Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 207 insertions, 109 deletions

diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 69ad623b7..129f8d235 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -4,7 +4,6 @@ version = "0.0.0"
 edition = "2021"
 
 [lib]
-doctest = false
 
 [dependencies]
 rustc_arena = { path = "../rustc_arena" }
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index e7c26bd72..4ef4aad90 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -314,74 +314,75 @@ pub enum Res<Id = hir::HirId> {
     /// **Belongs to the type namespace.**
     PrimTy(hir::PrimTy),
 
-    /// The `Self` type, optionally with the [`DefId`] of the trait it belongs to and
-    /// optionally with the [`DefId`] of the item introducing the `Self` type alias.
+    /// The `Self` type, as used within a trait.
+    ///
+    /// **Belongs to the type namespace.**
+    ///
+    /// See the examples on [`Res::SelfTyAlias`] for details.
+    SelfTyParam {
+        /// The trait this `Self` is a generic parameter for.
+        trait_: DefId,
+    },
+
+    /// The `Self` type, as used somewhere other than within a trait.
     ///
     /// **Belongs to the type namespace.**
     ///
     /// Examples:
     /// ```
-    /// struct Bar(Box<Self>);
-    /// // `Res::SelfTy { trait_: None, alias_of: Some(Bar) }`
+    /// struct Bar(Box<Self>); // SelfTyAlias
     ///
     /// trait Foo {
-    ///     fn foo() -> Box<Self>;
-    ///     // `Res::SelfTy { trait_: Some(Foo), alias_of: None }`
+    ///     fn foo() -> Box<Self>; // SelfTyParam
     /// }
     ///
     /// impl Bar {
     ///     fn blah() {
-    ///         let _: Self;
-    ///         // `Res::SelfTy { trait_: None, alias_of: Some(::{impl#0}) }`
+    ///         let _: Self; // SelfTyAlias
     ///     }
     /// }
     ///
     /// impl Foo for Bar {
-    ///     fn foo() -> Box<Self> {
-    ///     // `Res::SelfTy { trait_: Some(Foo), alias_of: Some(::{impl#1}) }`
-    ///         let _: Self;
-    ///         // `Res::SelfTy { trait_: Some(Foo), alias_of: Some(::{impl#1}) }`
+    ///     fn foo() -> Box<Self> { // SelfTyAlias
+    ///         let _: Self;        // SelfTyAlias
     ///
     ///         todo!()
     ///     }
     /// }
     /// ```
-    ///
     /// *See also [`Res::SelfCtor`].*
     ///
-    /// -----
-    ///
-    /// HACK(min_const_generics): self types also have an optional requirement to **not** mention
-    /// any generic parameters to allow the following with `min_const_generics`:
-    /// ```
-    /// # struct Foo;
-    /// impl Foo { fn test() -> [u8; std::mem::size_of::<Self>()] { todo!() } }
-    ///
-    /// struct Bar([u8; baz::<Self>()]);
-    /// const fn baz<T>() -> usize { 10 }
-    /// ```
-    /// We do however allow `Self` in repeat expression even if it is generic to not break code
-    /// which already works on stable while causing the `const_evaluatable_unchecked` future compat
-    /// lint:
-    /// ```
-    /// fn foo<T>() {
-    ///     let _bar = [1_u8; std::mem::size_of::<*mut T>()];
-    /// }
-    /// ```
-    // FIXME(generic_const_exprs): Remove this bodge once that feature is stable.
-    SelfTy {
-        /// The trait this `Self` is a generic arg for.
-        trait_: Option<DefId>,
+    SelfTyAlias {
         /// The item introducing the `Self` type alias. Can be used in the `type_of` query
-        /// to get the underlying type. Additionally whether the `Self` type is disallowed
-        /// from mentioning generics (i.e. when used in an anonymous constant).
-        alias_to: Option<(DefId, bool)>,
-    },
+        /// to get the underlying type.
+        alias_to: DefId,
 
-    /// A tool attribute module; e.g., the `rustfmt` in `#[rustfmt::skip]`.
-    ///
-    /// **Belongs to the type namespace.**
-    ToolMod,
+        /// Whether the `Self` type is disallowed from mentioning generics (i.e. when used in an
+        /// anonymous constant).
+        ///
+        /// HACK(min_const_generics): self types also have an optional requirement to **not**
+        /// mention any generic parameters to allow the following with `min_const_generics`:
+        /// ```
+        /// # struct Foo;
+        /// impl Foo { fn test() -> [u8; std::mem::size_of::<Self>()] { todo!() } }
+        ///
+        /// struct Bar([u8; baz::<Self>()]);
+        /// const fn baz<T>() -> usize { 10 }
+        /// ```
+        /// We do however allow `Self` in repeat expression even if it is generic to not break code
+        /// which already works on stable while causing the `const_evaluatable_unchecked` future
+        /// compat lint:
+        /// ```
+        /// fn foo<T>() {
+        ///     let _bar = [1_u8; std::mem::size_of::<*mut T>()];
+        /// }
+        /// ```
+        // FIXME(generic_const_exprs): Remove this bodge once that feature is stable.
+        forbid_generic: bool,
+
+        /// Is this within an `impl Foo for bar`?
+        is_trait_impl: bool,
+    },
 
     // Value namespace
     /// The `Self` constructor, along with the [`DefId`]
@@ -389,7 +390,7 @@ pub enum Res<Id = hir::HirId> {
     ///
     /// **Belongs to the value namespace.**
     ///
-    /// *See also [`Res::SelfTy`].*
+    /// *See also [`Res::SelfTyParam`] and [`Res::SelfTyAlias`].*
     SelfCtor(DefId),
 
     /// A local variable or function parameter.
@@ -397,6 +398,11 @@ pub enum Res<Id = hir::HirId> {
     /// **Belongs to the value namespace.**
     Local(Id),
 
+    /// A tool attribute module; e.g., the `rustfmt` in `#[rustfmt::skip]`.
+    ///
+    /// **Belongs to the type namespace.**
+    ToolMod,
+
     // Macro namespace
     /// An attribute that is *not* implemented via macro.
     /// E.g., `#[inline]` and `#[rustfmt::skip]`, which are essentially directives,
@@ -458,6 +464,16 @@ impl PartialRes {
     pub fn unresolved_segments(&self) -> usize {
         self.unresolved_segments
     }
+
+    #[inline]
+    pub fn full_res(&self) -> Option<Res<NodeId>> {
+        (self.unresolved_segments == 0).then_some(self.base_res)
+    }
+
+    #[inline]
+    pub fn expect_full_res(&self) -> Res<NodeId> {
+        self.full_res().expect("unexpected unresolved segments")
+    }
 }
 
 /// Different kinds of symbols can coexist even if they share the same textual name.
@@ -606,7 +622,8 @@ impl<Id> Res<Id> {
 
             Res::Local(..)
             | Res::PrimTy(..)
-            | Res::SelfTy { .. }
+            | Res::SelfTyParam { .. }
+            | Res::SelfTyAlias { .. }
             | Res::SelfCtor(..)
             | Res::ToolMod
             | Res::NonMacroAttr(..)
@@ -629,7 +646,7 @@ impl<Id> Res<Id> {
             Res::SelfCtor(..) => "self constructor",
             Res::PrimTy(..) => "builtin type",
             Res::Local(..) => "local variable",
-            Res::SelfTy { .. } => "self type",
+            Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => "self type",
             Res::ToolMod => "tool module",
             Res::NonMacroAttr(attr_kind) => attr_kind.descr(),
             Res::Err => "unresolved item",
@@ -652,7 +669,10 @@ impl<Id> Res<Id> {
             Res::SelfCtor(id) => Res::SelfCtor(id),
             Res::PrimTy(id) => Res::PrimTy(id),
             Res::Local(id) => Res::Local(map(id)),
-            Res::SelfTy { trait_, alias_to } => Res::SelfTy { trait_, alias_to },
+            Res::SelfTyParam { trait_ } => Res::SelfTyParam { trait_ },
+            Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } => {
+                Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl }
+            }
             Res::ToolMod => Res::ToolMod,
             Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
             Res::Err => Res::Err,
@@ -665,7 +685,10 @@ impl<Id> Res<Id> {
             Res::SelfCtor(id) => Res::SelfCtor(id),
             Res::PrimTy(id) => Res::PrimTy(id),
             Res::Local(id) => Res::Local(map(id)?),
-            Res::SelfTy { trait_, alias_to } => Res::SelfTy { trait_, alias_to },
+            Res::SelfTyParam { trait_ } => Res::SelfTyParam { trait_ },
+            Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } => {
+                Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl }
+            }
             Res::ToolMod => Res::ToolMod,
             Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
             Res::Err => Res::Err,
@@ -692,7 +715,9 @@ impl<Id> Res<Id> {
     pub fn ns(&self) -> Option<Namespace> {
         match self {
             Res::Def(kind, ..) => kind.ns(),
-            Res::PrimTy(..) | Res::SelfTy { .. } | Res::ToolMod => Some(Namespace::TypeNS),
+            Res::PrimTy(..) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::ToolMod => {
+                Some(Namespace::TypeNS)
+            }
             Res::SelfCtor(..) | Res::Local(..) => Some(Namespace::ValueNS),
             Res::NonMacroAttr(..) => Some(Namespace::MacroNS),
             Res::Err => None,
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index a8436ea64..ef00c1ffc 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1,6 +1,6 @@
 use crate::def::{CtorKind, DefKind, Res};
 use crate::def_id::DefId;
-pub(crate) use crate::hir_id::{HirId, ItemLocalId};
+pub(crate) use crate::hir_id::{HirId, ItemLocalId, OwnerId};
 use crate::intravisit::FnKind;
 use crate::LangItem;
 
@@ -731,6 +731,7 @@ pub enum PredicateOrigin {
 /// A type bound (e.g., `for<'c> Foo: Send + Clone + 'c`).
 #[derive(Debug, HashStable_Generic)]
 pub struct WhereBoundPredicate<'hir> {
+    pub hir_id: HirId,
     pub span: Span,
     /// Origin of the predicate.
     pub origin: PredicateOrigin,
@@ -2206,14 +2207,14 @@ pub struct FnSig<'hir> {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub struct TraitItemId {
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
 }
 
 impl TraitItemId {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 }
 
@@ -2224,7 +2225,7 @@ impl TraitItemId {
 #[derive(Debug, HashStable_Generic)]
 pub struct TraitItem<'hir> {
     pub ident: Ident,
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
     pub generics: &'hir Generics<'hir>,
     pub kind: TraitItemKind<'hir>,
     pub span: Span,
@@ -2235,11 +2236,11 @@ impl TraitItem<'_> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 
     pub fn trait_item_id(&self) -> TraitItemId {
-        TraitItemId { def_id: self.def_id }
+        TraitItemId { owner_id: self.owner_id }
     }
 }
 
@@ -2270,14 +2271,14 @@ pub enum TraitItemKind<'hir> {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub struct ImplItemId {
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
 }
 
 impl ImplItemId {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 }
 
@@ -2285,7 +2286,7 @@ impl ImplItemId {
 #[derive(Debug, HashStable_Generic)]
 pub struct ImplItem<'hir> {
     pub ident: Ident,
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
     pub generics: &'hir Generics<'hir>,
     pub kind: ImplItemKind<'hir>,
     pub defaultness: Defaultness,
@@ -2297,11 +2298,11 @@ impl ImplItem<'_> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 
     pub fn impl_item_id(&self) -> ImplItemId {
-        ImplItemId { def_id: self.def_id }
+        ImplItemId { owner_id: self.owner_id }
     }
 }
 
@@ -2314,7 +2315,7 @@ pub enum ImplItemKind<'hir> {
     /// An associated function implementation with the given signature and body.
     Fn(FnSig<'hir>, BodyId),
     /// An associated type.
-    TyAlias(&'hir Ty<'hir>),
+    Type(&'hir Ty<'hir>),
 }
 
 // The name of the associated type for `Fn` return types.
@@ -2403,8 +2404,9 @@ impl<'hir> Ty<'hir> {
             return None;
         };
         match path.res {
-            Res::Def(DefKind::TyParam, def_id)
-            | Res::SelfTy { trait_: Some(def_id), alias_to: None } => Some((def_id, segment.ident)),
+            Res::Def(DefKind::TyParam, def_id) | Res::SelfTyParam { trait_: def_id } => {
+                Some((def_id, segment.ident))
+            }
             _ => None,
         }
     }
@@ -2416,6 +2418,30 @@ impl<'hir> Ty<'hir> {
         }
         final_ty
     }
+
+    pub fn find_self_aliases(&self) -> Vec<Span> {
+        use crate::intravisit::Visitor;
+        struct MyVisitor(Vec<Span>);
+        impl<'v> Visitor<'v> for MyVisitor {
+            fn visit_ty(&mut self, t: &'v Ty<'v>) {
+                if matches!(
+                    &t.kind,
+                    TyKind::Path(QPath::Resolved(
+                        _,
+                        Path { res: crate::def::Res::SelfTyAlias { .. }, .. },
+                    ))
+                ) {
+                    self.0.push(t.span);
+                    return;
+                }
+                crate::intravisit::walk_ty(self, t);
+            }
+        }
+
+        let mut my_visitor = MyVisitor(vec![]);
+        my_visitor.visit_ty(self);
+        my_visitor.0
+    }
 }
 
 /// Not represented directly in the AST; referred to by name through a `ty_path`.
@@ -2888,14 +2914,14 @@ impl<'hir> VariantData<'hir> {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
 pub struct ItemId {
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
 }
 
 impl ItemId {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 }
 
@@ -2905,7 +2931,7 @@ impl ItemId {
 #[derive(Debug, HashStable_Generic)]
 pub struct Item<'hir> {
     pub ident: Ident,
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
     pub kind: ItemKind<'hir>,
     pub span: Span,
     pub vis_span: Span,
@@ -2915,11 +2941,11 @@ impl Item<'_> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 
     pub fn item_id(&self) -> ItemId {
-        ItemId { def_id: self.def_id }
+        ItemId { owner_id: self.owner_id }
     }
 }
 
@@ -3132,14 +3158,14 @@ pub enum AssocItemKind {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub struct ForeignItemId {
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
 }
 
 impl ForeignItemId {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 }
 
@@ -3160,7 +3186,7 @@ pub struct ForeignItemRef {
 pub struct ForeignItem<'hir> {
     pub ident: Ident,
     pub kind: ForeignItemKind<'hir>,
-    pub def_id: LocalDefId,
+    pub owner_id: OwnerId,
     pub span: Span,
     pub vis_span: Span,
 }
@@ -3169,11 +3195,11 @@ impl ForeignItem<'_> {
     #[inline]
     pub fn hir_id(&self) -> HirId {
         // Items are always HIR owners.
-        HirId::make_owner(self.def_id)
+        HirId::make_owner(self.owner_id.def_id)
     }
 
     pub fn foreign_item_id(&self) -> ForeignItemId {
-        ForeignItemId { def_id: self.def_id }
+        ForeignItemId { owner_id: self.owner_id }
     }
 }
 
@@ -3263,12 +3289,12 @@ impl<'hir> OwnerNode<'hir> {
         Node::generics(self.into())
     }
 
-    pub fn def_id(self) -> LocalDefId {
+    pub fn def_id(self) -> OwnerId {
         match self {
-            OwnerNode::Item(Item { def_id, .. })
-            | OwnerNode::TraitItem(TraitItem { def_id, .. })
-            | OwnerNode::ImplItem(ImplItem { def_id, .. })
-            | OwnerNode::ForeignItem(ForeignItem { def_id, .. }) => *def_id,
+            OwnerNode::Item(Item { owner_id, .. })
+            | OwnerNode::TraitItem(TraitItem { owner_id, .. })
+            | OwnerNode::ImplItem(ImplItem { owner_id, .. })
+            | OwnerNode::ForeignItem(ForeignItem { owner_id, .. }) => *owner_id,
             OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
         }
     }
@@ -3512,7 +3538,7 @@ impl<'hir> Node<'hir> {
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 mod size_asserts {
     use super::*;
-    // These are in alphabetical order, which is easy to maintain.
+    // tidy-alphabetical-start
     static_assert_size!(Block<'_>, 48);
     static_assert_size!(Body<'_>, 32);
     static_assert_size!(Expr<'_>, 64);
@@ -3520,30 +3546,27 @@ mod size_asserts {
     static_assert_size!(FnDecl<'_>, 40);
     static_assert_size!(ForeignItem<'_>, 72);
     static_assert_size!(ForeignItemKind<'_>, 40);
-    #[cfg(not(bootstrap))]
     static_assert_size!(GenericArg<'_>, 24);
     static_assert_size!(GenericBound<'_>, 48);
     static_assert_size!(Generics<'_>, 56);
     static_assert_size!(Impl<'_>, 80);
-    #[cfg(not(bootstrap))]
     static_assert_size!(ImplItem<'_>, 80);
-    #[cfg(not(bootstrap))]
     static_assert_size!(ImplItemKind<'_>, 32);
     static_assert_size!(Item<'_>, 80);
     static_assert_size!(ItemKind<'_>, 48);
     static_assert_size!(Local<'_>, 64);
     static_assert_size!(Param<'_>, 32);
     static_assert_size!(Pat<'_>, 72);
+    static_assert_size!(Path<'_>, 40);
+    static_assert_size!(PathSegment<'_>, 48);
     static_assert_size!(PatKind<'_>, 48);
-    static_assert_size!(Path<'_>, 48);
-    static_assert_size!(PathSegment<'_>, 56);
     static_assert_size!(QPath<'_>, 24);
+    static_assert_size!(Res, 12);
     static_assert_size!(Stmt<'_>, 32);
     static_assert_size!(StmtKind<'_>, 16);
-    #[cfg(not(bootstrap))]
     static_assert_size!(TraitItem<'_>, 88);
-    #[cfg(not(bootstrap))]
     static_assert_size!(TraitItemKind<'_>, 48);
     static_assert_size!(Ty<'_>, 48);
     static_assert_size!(TyKind<'_>, 32);
+    // tidy-alphabetical-end
 }
diff --git a/compiler/rustc_hir/src/hir_id.rs b/compiler/rustc_hir/src/hir_id.rs
index 84b0740c7..752f760ea 100644
--- a/compiler/rustc_hir/src/hir_id.rs
+++ b/compiler/rustc_hir/src/hir_id.rs
@@ -1,6 +1,43 @@
-use crate::def_id::{LocalDefId, CRATE_DEF_ID};
+use crate::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
+use rustc_span::{def_id::DefPathHash, HashStableContext};
 use std::fmt;
 
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Encodable, Decodable)]
+pub struct OwnerId {
+    pub def_id: LocalDefId,
+}
+
+impl From<OwnerId> for HirId {
+    fn from(owner: OwnerId) -> HirId {
+        HirId { owner, local_id: ItemLocalId::from_u32(0) }
+    }
+}
+
+impl OwnerId {
+    #[inline]
+    pub fn to_def_id(self) -> DefId {
+        self.def_id.to_def_id()
+    }
+}
+
+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"),
@@ -15,22 +52,23 @@ use std::fmt;
 #[derive(Encodable, Decodable, HashStable_Generic)]
 #[rustc_pass_by_value]
 pub struct HirId {
-    pub owner: LocalDefId,
+    pub owner: OwnerId,
     pub local_id: ItemLocalId,
 }
 
 impl HirId {
     /// Signal local id which should never be used.
-    pub const INVALID: HirId = HirId { owner: CRATE_DEF_ID, local_id: ItemLocalId::INVALID };
+    pub const INVALID: HirId =
+        HirId { owner: OwnerId { def_id: CRATE_DEF_ID }, local_id: ItemLocalId::INVALID };
 
     #[inline]
-    pub fn expect_owner(self) -> LocalDefId {
+    pub fn expect_owner(self) -> OwnerId {
         assert_eq!(self.local_id.index(), 0);
         self.owner
     }
 
     #[inline]
-    pub fn as_owner(self) -> Option<LocalDefId> {
+    pub fn as_owner(self) -> Option<OwnerId> {
         if self.local_id.index() == 0 { Some(self.owner) } else { None }
     }
 
@@ -41,11 +79,14 @@ impl HirId {
 
     #[inline]
     pub fn make_owner(owner: LocalDefId) -> Self {
-        Self { owner, local_id: ItemLocalId::from_u32(0) }
+        Self { owner: OwnerId { def_id: owner }, local_id: ItemLocalId::from_u32(0) }
     }
 
     pub fn index(self) -> (usize, usize) {
-        (rustc_index::vec::Idx::index(self.owner), rustc_index::vec::Idx::index(self.local_id))
+        (
+            rustc_index::vec::Idx::index(self.owner.def_id),
+            rustc_index::vec::Idx::index(self.local_id),
+        )
     }
 }
 
@@ -94,4 +135,7 @@ impl ItemLocalId {
 }
 
 /// The `HirId` corresponding to `CRATE_NODE_ID` and `CRATE_DEF_ID`.
-pub const CRATE_HIR_ID: HirId = HirId { owner: CRATE_DEF_ID, local_id: ItemLocalId::from_u32(0) };
+pub const CRATE_HIR_ID: HirId =
+    HirId { owner: OwnerId { def_id: CRATE_DEF_ID }, local_id: ItemLocalId::from_u32(0) };
+
+pub const CRATE_OWNER_ID: OwnerId = OwnerId { def_id: CRATE_DEF_ID };
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index 8f5f314ec..be77e6fd3 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -847,20 +847,28 @@ pub fn walk_where_predicate<'v, V: Visitor<'v>>(
 ) {
     match *predicate {
         WherePredicate::BoundPredicate(WhereBoundPredicate {
+            hir_id,
             ref bounded_ty,
             bounds,
             bound_generic_params,
-            ..
+            origin: _,
+            span: _,
         }) => {
+            visitor.visit_id(hir_id);
             visitor.visit_ty(bounded_ty);
             walk_list!(visitor, visit_param_bound, bounds);
             walk_list!(visitor, visit_generic_param, bound_generic_params);
         }
-        WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
+        WherePredicate::RegionPredicate(WhereRegionPredicate {
+            ref lifetime,
+            bounds,
+            span: _,
+            in_where_clause: _,
+        }) => {
             visitor.visit_lifetime(lifetime);
             walk_list!(visitor, visit_param_bound, bounds);
         }
-        WherePredicate::EqPredicate(WhereEqPredicate { ref lhs_ty, ref rhs_ty, .. }) => {
+        WherePredicate::EqPredicate(WhereEqPredicate { ref lhs_ty, ref rhs_ty, span: _ }) => {
             visitor.visit_ty(lhs_ty);
             visitor.visit_ty(rhs_ty);
         }
@@ -904,7 +912,7 @@ pub fn walk_fn<'v, V: Visitor<'v>>(
 
 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
     // N.B., deliberately force a compilation error if/when new fields are added.
-    let TraitItem { ident, generics, ref defaultness, ref kind, span, def_id: _ } = *trait_item;
+    let TraitItem { ident, generics, ref defaultness, ref kind, span, owner_id: _ } = *trait_item;
     let hir_id = trait_item.hir_id();
     visitor.visit_ident(ident);
     visitor.visit_generics(&generics);
@@ -944,7 +952,7 @@ pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref:
 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
     // N.B., deliberately force a compilation error if/when new fields are added.
     let ImplItem {
-        def_id: _,
+        owner_id: _,
         ident,
         ref generics,
         ref kind,
@@ -971,7 +979,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
                 impl_item.hir_id(),
             );
         }
-        ImplItemKind::TyAlias(ref ty) => {
+        ImplItemKind::Type(ref ty) => {
             visitor.visit_id(impl_item.hir_id());
             visitor.visit_ty(ty);
         }
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index 946da9265..1c4aa420c 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -4,8 +4,7 @@
 
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
-#![feature(const_btree_new)]
-#![cfg_attr(bootstrap, feature(let_else))]
+#![feature(const_btree_len)]
 #![feature(once_cell)]
 #![feature(min_specialization)]
 #![feature(never_type)]
diff --git a/compiler/rustc_hir/src/stable_hash_impls.rs b/compiler/rustc_hir/src/stable_hash_impls.rs
index 5b9c42686..23423e8f3 100644
--- a/compiler/rustc_hir/src/stable_hash_impls.rs
+++ b/compiler/rustc_hir/src/stable_hash_impls.rs
@@ -20,7 +20,7 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for HirId {
 
     #[inline]
     fn to_stable_hash_key(&self, hcx: &HirCtx) -> (DefPathHash, ItemLocalId) {
-        let def_path_hash = self.owner.to_stable_hash_key(hcx);
+        let def_path_hash = self.owner.def_id.to_stable_hash_key(hcx);
         (def_path_hash, self.local_id)
     }
 }
@@ -49,7 +49,7 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ItemId {
 
     #[inline]
     fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
-        self.def_id.to_stable_hash_key(hcx)
+        self.owner_id.def_id.to_stable_hash_key(hcx)
     }
 }
 
@@ -58,7 +58,7 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for TraitItemId {
 
     #[inline]
     fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
-        self.def_id.to_stable_hash_key(hcx)
+        self.owner_id.def_id.to_stable_hash_key(hcx)
     }
 }
 
@@ -67,7 +67,7 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ImplItemId {
 
     #[inline]
     fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
-        self.def_id.to_stable_hash_key(hcx)
+        self.owner_id.def_id.to_stable_hash_key(hcx)
     }
 }
 
@@ -76,7 +76,7 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ForeignItemId
 
     #[inline]
     fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
-        self.def_id.to_stable_hash_key(hcx)
+        self.owner_id.def_id.to_stable_hash_key(hcx)
     }
 }