Only store a LocalDefId in hir::TraitItem.

compiler/rustc_ast_lowering/src/item.rs

@@ -92,7 +92,7 @@ impl<'a> Visitor<'a> for ItemLowerer<'a, '_, '_> {
         self.lctx.with_hir_id_owner(item.id, |lctx| match ctxt {
             AssocCtxt::Trait => {
                 let hir_item = lctx.lower_trait_item(item);
-                let id = hir::TraitItemId { hir_id: hir_item.hir_id };
+                let id = hir_item.trait_item_id();
                 lctx.trait_items.insert(id, hir_item);
                 lctx.modules.get_mut(&lctx.current_module).unwrap().trait_items.insert(id);
             }
@@ -846,7 +846,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         };
 
         hir::TraitItem {
-            hir_id: self.lower_node_id(i.id),
+            def_id: trait_item_def_id,
             ident: i.ident,
             attrs: self.lower_attrs(&i.attrs),
             generics,
@@ -866,7 +866,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             }
             AssocItemKind::MacCall(..) => unimplemented!(),
         };
-        let id = hir::TraitItemId { hir_id: self.lower_node_id(i.id) };
+        let id = hir::TraitItemId { def_id: self.lower_node_id(i.id).expect_owner() };
         let defaultness = hir::Defaultness::Default { has_value: has_default };
         hir::TraitItemRef { id, ident: i.ident, span: i.span, defaultness, kind }
     }

compiler/rustc_hir/src/hir.rs

@@ -1907,7 +1907,14 @@ pub struct FnSig<'hir> {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Encodable, Debug)]
 pub struct TraitItemId {
-    pub hir_id: HirId,
+    pub def_id: LocalDefId,
+}
+
+impl TraitItemId {
+    pub fn hir_id(&self) -> HirId {
+        // Items are always HIR owners.
+        HirId::make_owner(self.def_id)
+    }
 }
 
 /// Represents an item declaration within a trait declaration,
@@ -1917,13 +1924,24 @@ pub struct TraitItemId {
 #[derive(Debug)]
 pub struct TraitItem<'hir> {
     pub ident: Ident,
-    pub hir_id: HirId,
+    pub def_id: LocalDefId,
     pub attrs: &'hir [Attribute],
     pub generics: Generics<'hir>,
     pub kind: TraitItemKind<'hir>,
     pub span: Span,
 }
 
+impl TraitItem<'_> {
+    pub fn hir_id(&self) -> HirId {
+        // Items are always HIR owners.
+        HirId::make_owner(self.def_id)
+    }
+
+    pub fn trait_item_id(&self) -> TraitItemId {
+        TraitItemId { def_id: self.def_id }
+    }
+}
+
 /// Represents a trait method's body (or just argument names).
 #[derive(Encodable, Debug, HashStable_Generic)]
 pub enum TraitFn<'hir> {
@@ -2885,9 +2903,10 @@ impl<'hir> Node<'hir> {
 
     pub fn hir_id(&self) -> Option<HirId> {
         match self {
-            Node::Item(Item { def_id, .. }) => Some(HirId::make_owner(*def_id)),
+            Node::Item(Item { def_id, .. }) | Node::TraitItem(TraitItem { def_id, .. }) => {
+                Some(HirId::make_owner(*def_id))
+            }
             Node::ForeignItem(ForeignItem { hir_id, .. })
-            | Node::TraitItem(TraitItem { hir_id, .. })
             | Node::ImplItem(ImplItem { hir_id, .. })
             | Node::Field(StructField { hir_id, .. })
             | Node::AnonConst(AnonConst { hir_id, .. })
@@ -2922,7 +2941,7 @@ mod size_asserts {
     rustc_data_structures::static_assert_size!(super::Ty<'static>, 72);
 
     rustc_data_structures::static_assert_size!(super::Item<'static>, 200);
-    rustc_data_structures::static_assert_size!(super::TraitItem<'static>, 152);
+    rustc_data_structures::static_assert_size!(super::TraitItem<'static>, 144);
     rustc_data_structures::static_assert_size!(super::ImplItem<'static>, 168);
     rustc_data_structures::static_assert_size!(super::ForeignItem<'static>, 160);
 }

compiler/rustc_hir/src/intravisit.rs

@@ -964,12 +964,12 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v Trai
     visitor.visit_generics(&trait_item.generics);
     match trait_item.kind {
         TraitItemKind::Const(ref ty, default) => {
-            visitor.visit_id(trait_item.hir_id);
+            visitor.visit_id(trait_item.hir_id());
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_nested_body, default);
         }
         TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
-            visitor.visit_id(trait_item.hir_id);
+            visitor.visit_id(trait_item.hir_id());
             visitor.visit_fn_decl(&sig.decl);
             for &param_name in param_names {
                 visitor.visit_ident(param_name);
@@ -981,11 +981,11 @@ pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v Trai
                 &sig.decl,
                 body_id,
                 trait_item.span,
-                trait_item.hir_id,
+                trait_item.hir_id(),
             );
         }
         TraitItemKind::Type(bounds, ref default) => {
-            visitor.visit_id(trait_item.hir_id);
+            visitor.visit_id(trait_item.hir_id());
             walk_list!(visitor, visit_param_bound, bounds);
             walk_list!(visitor, visit_ty, default);
         }

compiler/rustc_hir/src/stable_hash_impls.rs

@@ -44,11 +44,11 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ItemId {
 }
 
 impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for TraitItemId {
-    type KeyType = (DefPathHash, ItemLocalId);
+    type KeyType = DefPathHash;
 
     #[inline]
-    fn to_stable_hash_key(&self, hcx: &HirCtx) -> (DefPathHash, ItemLocalId) {
-        self.hir_id.to_stable_hash_key(hcx)
+    fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
+        hcx.local_def_path_hash(self.def_id)
     }
 }
 
@@ -109,7 +109,7 @@ impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ImplItemId {
 
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for TraitItemId {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_reference_to_item(self.hir_id, hasher)
+        hcx.hash_reference_to_item(self.hir_id(), hasher)
     }
 }
 
@@ -139,7 +139,7 @@ impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for VisibilityKind<'_>
 
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for TraitItem<'_> {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        let TraitItem { hir_id: _, ident, ref attrs, ref generics, ref kind, span } = *self;
+        let TraitItem { def_id: _, ident, ref attrs, ref generics, ref kind, span } = *self;
 
         hcx.hash_hir_item_like(|hcx| {
             ident.name.hash_stable(hcx, hasher);

compiler/rustc_hir_pretty/src/lib.rs

@@ -934,7 +934,7 @@ impl<'a> State<'a> {
     }
 
     pub fn print_trait_item(&mut self, ti: &hir::TraitItem<'_>) {
-        self.ann.pre(self, AnnNode::SubItem(ti.hir_id));
+        self.ann.pre(self, AnnNode::SubItem(ti.hir_id()));
         self.hardbreak_if_not_bol();
         self.maybe_print_comment(ti.span.lo());
         self.print_outer_attributes(&ti.attrs);
@@ -969,7 +969,7 @@ impl<'a> State<'a> {
                 );
             }
         }
-        self.ann.post(self, AnnNode::SubItem(ti.hir_id))
+        self.ann.post(self, AnnNode::SubItem(ti.hir_id()))
     }
 
     pub fn print_impl_item(&mut self, ii: &hir::ImplItem<'_>) {

compiler/rustc_incremental/src/assert_dep_graph.rs

@@ -172,7 +172,7 @@ impl Visitor<'tcx> for IfThisChanged<'tcx> {
     }
 
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
-        self.process_attrs(trait_item.hir_id, &trait_item.attrs);
+        self.process_attrs(trait_item.hir_id(), &trait_item.attrs);
         intravisit::walk_trait_item(self, trait_item);
     }
 

compiler/rustc_incremental/src/persist/dirty_clean.rs

@@ -454,7 +454,7 @@ impl ItemLikeVisitor<'tcx> for DirtyCleanVisitor<'tcx> {
     }
 
     fn visit_trait_item(&mut self, item: &hir::TraitItem<'_>) {
-        self.check_item(item.hir_id, item.span);
+        self.check_item(item.hir_id(), item.span);
     }
 
     fn visit_impl_item(&mut self, item: &hir::ImplItem<'_>) {

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs

@@ -8,8 +8,7 @@ use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorRepor
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_ty, ErasedMap, NestedVisitorMap, Visitor};
 use rustc_hir::{
-    self as hir, GenericBound, ImplItem, Item, ItemKind, Lifetime, LifetimeName, Node, TraitItem,
-    TyKind,
+    self as hir, GenericBound, ImplItem, Item, ItemKind, Lifetime, LifetimeName, Node, TyKind,
 };
 use rustc_middle::ty::{self, AssocItemContainer, RegionKind, Ty, TypeFoldable, TypeVisitor};
 use rustc_span::symbol::Ident;
@@ -352,8 +351,8 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                     _ => None,
                 }
             }
-            Some(Node::TraitItem(TraitItem { ident, hir_id, .. })) => {
-                let parent_id = tcx.hir().get_parent_item(*hir_id);
+            Some(Node::TraitItem(trait_item)) => {
+                let parent_id = tcx.hir().get_parent_item(trait_item.hir_id());
                 match tcx.hir().find(parent_id) {
                     Some(Node::Item(Item { kind: ItemKind::Trait(..), .. })) => {
                         // The method being called is defined in the `trait`, but the `'static`
@@ -389,7 +388,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                             })
                             .next()
                         {
-                            Some(self_ty) => Some((*ident, self_ty)),
+                            Some(self_ty) => Some((trait_item.ident, self_ty)),
                             _ => None,
                         }
                     }

compiler/rustc_lint/src/builtin.rs

@@ -586,7 +586,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
                 if let hir::VisibilityKind::Inherited = it.vis.node {
                     self.private_traits.insert(it.hir_id());
                     for trait_item_ref in trait_item_refs {
-                        self.private_traits.insert(trait_item_ref.id.hir_id);
+                        self.private_traits.insert(trait_item_ref.id.hir_id());
                     }
                     return;
                 }
@@ -626,16 +626,15 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'_>, trait_item: &hir::TraitItem<'_>) {
-        if self.private_traits.contains(&trait_item.hir_id) {
+        if self.private_traits.contains(&trait_item.hir_id()) {
             return;
         }
 
-        let def_id = cx.tcx.hir().local_def_id(trait_item.hir_id);
-        let (article, desc) = cx.tcx.article_and_description(def_id.to_def_id());
+        let (article, desc) = cx.tcx.article_and_description(trait_item.def_id.to_def_id());
 
         self.check_missing_docs_attrs(
             cx,
-            Some(trait_item.hir_id),
+            Some(trait_item.hir_id()),
             &trait_item.attrs,
             trait_item.span,
             article,

compiler/rustc_lint/src/late.rs

@@ -301,8 +301,8 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
         let generics = self.context.generics.take();
         self.context.generics = Some(&trait_item.generics);
-        self.with_lint_attrs(trait_item.hir_id, &trait_item.attrs, |cx| {
-            cx.with_param_env(trait_item.hir_id, |cx| {
+        self.with_lint_attrs(trait_item.hir_id(), &trait_item.attrs, |cx| {
+            cx.with_param_env(trait_item.hir_id(), |cx| {
                 lint_callback!(cx, check_trait_item, trait_item);
                 hir_visit::walk_trait_item(cx, trait_item);
                 lint_callback!(cx, check_trait_item_post, trait_item);

compiler/rustc_lint/src/levels.rs

@@ -631,7 +631,7 @@ impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> {
     }
 
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
-        self.with_lint_attrs(trait_item.hir_id, &trait_item.attrs, |builder| {
+        self.with_lint_attrs(trait_item.hir_id(), &trait_item.attrs, |builder| {
             intravisit::walk_trait_item(builder, trait_item);
         });
     }

compiler/rustc_middle/src/hir/map/blocks.rs

@@ -229,7 +229,7 @@ impl<'a> FnLikeNode<'a> {
             },
             Node::TraitItem(ti) => match ti.kind {
                 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
-                    method(ti.hir_id, ti.ident, sig, None, body, ti.span, &ti.attrs)
+                    method(ti.hir_id(), ti.ident, sig, None, body, ti.span, &ti.attrs)
                 }
                 _ => bug!("trait method FnLikeNode that is not fn-like"),
             },

compiler/rustc_middle/src/hir/map/collector.rs

@@ -391,14 +391,10 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     }
 
     fn visit_trait_item(&mut self, ti: &'hir TraitItem<'hir>) {
-        debug_assert_eq!(
-            ti.hir_id.owner,
-            self.definitions.opt_hir_id_to_local_def_id(ti.hir_id).unwrap()
-        );
-        self.with_dep_node_owner(ti.hir_id.owner, ti, |this, hash| {
-            this.insert_with_hash(ti.span, ti.hir_id, Node::TraitItem(ti), hash);
+        self.with_dep_node_owner(ti.def_id, ti, |this, hash| {
+            this.insert_with_hash(ti.span, ti.hir_id(), Node::TraitItem(ti), hash);
 
-            this.with_parent(ti.hir_id, |this| {
+            this.with_parent(ti.hir_id(), |this| {
                 intravisit::walk_trait_item(this, ti);
             });
         });

compiler/rustc_middle/src/hir/map/mod.rs

@@ -308,7 +308,7 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
-        match self.find(id.hir_id).unwrap() {
+        match self.find(id.hir_id()).unwrap() {
             Node::TraitItem(item) => item,
             _ => bug!(),
         }

compiler/rustc_middle/src/ty/error.rs

@@ -816,7 +816,7 @@ fn foo(&self) -> Self::T { String::new() }
                             // an assoc type as a return type (#72076).
                             if let hir::Defaultness::Default { has_value: true } = item.defaultness
                             {
-                                if self.type_of(self.hir().local_def_id(item.id.hir_id)) == found {
+                                if self.type_of(item.id.def_id) == found {
                                     db.span_label(
                                         item.span,
                                         "associated type defaults can't be assumed inside the \

compiler/rustc_passes/src/check_attr.rs

@@ -1081,7 +1081,13 @@ impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
 
     fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) {
         let target = Target::from_trait_item(trait_item);
-        self.check_attributes(trait_item.hir_id, &trait_item.attrs, &trait_item.span, target, None);
+        self.check_attributes(
+            trait_item.hir_id(),
+            &trait_item.attrs,
+            &trait_item.span,
+            target,
+            None,
+        );
         intravisit::walk_trait_item(self, trait_item)
     }
 

compiler/rustc_passes/src/dead.rs

@@ -440,9 +440,9 @@ impl<'v, 'k, 'tcx> ItemLikeVisitor<'v> for LifeSeeder<'k, 'tcx> {
     fn visit_trait_item(&mut self, trait_item: &hir::TraitItem<'_>) {
         use hir::TraitItemKind::{Const, Fn};
         if matches!(trait_item.kind, Const(_, Some(_)) | Fn(_, hir::TraitFn::Provided(_)))
-            && has_allow_dead_code_or_lang_attr(self.tcx, trait_item.hir_id, &trait_item.attrs)
+            && has_allow_dead_code_or_lang_attr(self.tcx, trait_item.hir_id(), &trait_item.attrs)
         {
-            self.worklist.push(trait_item.hir_id);
+            self.worklist.push(trait_item.hir_id());
         }
     }
 

compiler/rustc_passes/src/diagnostic_items.rs

@@ -31,7 +31,7 @@ impl<'v, 'tcx> ItemLikeVisitor<'v> for DiagnosticItemCollector<'tcx> {
     }
 
     fn visit_trait_item(&mut self, trait_item: &hir::TraitItem<'_>) {
-        self.observe_item(&trait_item.attrs, trait_item.hir_id);
+        self.observe_item(&trait_item.attrs, trait_item.hir_id());
     }
 
     fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {

compiler/rustc_passes/src/hir_id_validator.rs

@@ -61,7 +61,7 @@ impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
 
     fn visit_trait_item(&mut self, i: &'hir hir::TraitItem<'hir>) {
         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
-        inner_visitor.check(i.hir_id, |this| intravisit::walk_trait_item(this, i));
+        inner_visitor.check(i.hir_id(), |this| intravisit::walk_trait_item(this, i));
     }
 
     fn visit_impl_item(&mut self, i: &'hir hir::ImplItem<'hir>) {

compiler/rustc_passes/src/hir_stats.rs

@@ -187,7 +187,7 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     }
 
     fn visit_trait_item(&mut self, ti: &'v hir::TraitItem<'v>) {
-        self.record("TraitItem", Id::Node(ti.hir_id), ti);
+        self.record("TraitItem", Id::Node(ti.hir_id()), ti);
         hir_visit::walk_trait_item(self, ti)
     }
 

compiler/rustc_passes/src/lang_items.rs

@@ -42,7 +42,7 @@ impl ItemLikeVisitor<'v> for LanguageItemCollector<'tcx> {
     fn visit_trait_item(&mut self, trait_item: &hir::TraitItem<'_>) {
         self.check_for_lang(
             Target::from_trait_item(trait_item),
-            trait_item.hir_id,
+            trait_item.hir_id(),
             trait_item.attrs,
         )
     }

compiler/rustc_passes/src/stability.rs

@@ -389,7 +389,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
 
     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) {
         self.annotate(
-            ti.hir_id,
+            ti.hir_id(),
             &ti.attrs,
             ti.span,
             AnnotationKind::Required,
@@ -571,7 +571,7 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
     }
 
     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) {
-        self.check_missing_stability(ti.hir_id, ti.span);
+        self.check_missing_stability(ti.hir_id(), ti.span);
         intravisit::walk_trait_item(self, ti);
     }