Only store a LocalDefId in hir::ImplItem.

Author: cjgillot

compiler/rustc_ast_lowering/src/item.rs

@@ -98,7 +98,7 @@ impl<'a> Visitor<'a> for ItemLowerer<'a, '_, '_> {
             }
             AssocCtxt::Impl => {
                 let hir_item = lctx.lower_impl_item(item);
-                let id = hir::ImplItemId { hir_id: hir_item.hir_id };
+                let id = hir_item.impl_item_id();
                 lctx.impl_items.insert(id, hir_item);
                 lctx.modules.get_mut(&lctx.current_module).unwrap().impl_items.insert(id);
             }
@@ -931,7 +931,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let has_value = true;
         let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value);
         hir::ImplItem {
-            hir_id: self.lower_node_id(i.id),
+            def_id: self.lower_node_id(i.id).expect_owner(),
             ident: i.ident,
             attrs: self.lower_attrs(&i.attrs),
             generics,
@@ -947,7 +947,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let has_value = true;
         let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value);
         hir::ImplItemRef {
-            id: hir::ImplItemId { hir_id: self.lower_node_id(i.id) },
+            id: hir::ImplItemId { def_id: self.lower_node_id(i.id).expect_owner() },
             ident: i.ident,
             span: i.span,
             vis: self.lower_visibility(&i.vis, Some(i.id)),

compiler/rustc_hir/src/hir.rs

@@ -1969,14 +1969,21 @@ pub enum TraitItemKind<'hir> {
 // so it can fetched later.
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Encodable, Debug)]
 pub struct ImplItemId {
-    pub hir_id: HirId,
+    pub def_id: LocalDefId,
+}
+
+impl ImplItemId {
+    pub fn hir_id(&self) -> HirId {
+        // Items are always HIR owners.
+        HirId::make_owner(self.def_id)
+    }
 }
 
 /// Represents anything within an `impl` block.
 #[derive(Debug)]
 pub struct ImplItem<'hir> {
     pub ident: Ident,
-    pub hir_id: HirId,
+    pub def_id: LocalDefId,
     pub vis: Visibility<'hir>,
     pub defaultness: Defaultness,
     pub attrs: &'hir [Attribute],
@@ -1985,6 +1992,17 @@ pub struct ImplItem<'hir> {
     pub span: Span,
 }
 
+impl ImplItem<'_> {
+    pub fn hir_id(&self) -> HirId {
+        // Items are always HIR owners.
+        HirId::make_owner(self.def_id)
+    }
+
+    pub fn impl_item_id(&self) -> ImplItemId {
+        ImplItemId { def_id: self.def_id }
+    }
+}
+
 /// Represents various kinds of content within an `impl`.
 #[derive(Debug, HashStable_Generic)]
 pub enum ImplItemKind<'hir> {
@@ -2903,11 +2921,10 @@ impl<'hir> Node<'hir> {
 
     pub fn hir_id(&self) -> Option<HirId> {
         match self {
-            Node::Item(Item { def_id, .. }) | Node::TraitItem(TraitItem { def_id, .. }) => {
-                Some(HirId::make_owner(*def_id))
-            }
+            Node::Item(Item { def_id, .. })
+            | Node::TraitItem(TraitItem { def_id, .. })
+            | Node::ImplItem(ImplItem { def_id, .. }) => Some(HirId::make_owner(*def_id)),
             Node::ForeignItem(ForeignItem { hir_id, .. })
-            | Node::ImplItem(ImplItem { hir_id, .. })
             | Node::Field(StructField { hir_id, .. })
             | Node::AnonConst(AnonConst { hir_id, .. })
             | Node::Expr(Expr { hir_id, .. })

compiler/rustc_hir/src/intravisit.rs

@@ -1004,7 +1004,7 @@ 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 {
-        hir_id: _,
+        def_id: _,
         ident,
         ref vis,
         ref defaultness,
@@ -1021,7 +1021,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
     visitor.visit_generics(generics);
     match *kind {
         ImplItemKind::Const(ref ty, body) => {
-            visitor.visit_id(impl_item.hir_id);
+            visitor.visit_id(impl_item.hir_id());
             visitor.visit_ty(ty);
             visitor.visit_nested_body(body);
         }
@@ -1031,11 +1031,11 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplIt
                 &sig.decl,
                 body_id,
                 impl_item.span,
-                impl_item.hir_id,
+                impl_item.hir_id(),
             );
         }
         ImplItemKind::TyAlias(ref ty) => {
-            visitor.visit_id(impl_item.hir_id);
+            visitor.visit_id(impl_item.hir_id());
             visitor.visit_ty(ty);
         }
     }

compiler/rustc_hir/src/stable_hash_impls.rs

@@ -53,11 +53,11 @@ impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for TraitItemId {
 }
 
 impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ImplItemId {
-    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)
     }
 }
 
@@ -103,7 +103,7 @@ impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ForeignItemId {
 
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ImplItemId {
     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)
     }
 }
 
@@ -154,7 +154,7 @@ impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for TraitItem<'_> {
 impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for ImplItem<'_> {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
         let ImplItem {
-            hir_id: _,
+            def_id: _,
             ident,
             ref vis,
             defaultness,

compiler/rustc_hir_pretty/src/lib.rs

@@ -973,7 +973,7 @@ impl<'a> State<'a> {
     }
 
     pub fn print_impl_item(&mut self, ii: &hir::ImplItem<'_>) {
-        self.ann.pre(self, AnnNode::SubItem(ii.hir_id));
+        self.ann.pre(self, AnnNode::SubItem(ii.hir_id()));
         self.hardbreak_if_not_bol();
         self.maybe_print_comment(ii.span.lo());
         self.print_outer_attributes(&ii.attrs);
@@ -995,7 +995,7 @@ impl<'a> State<'a> {
                 self.print_associated_type(ii.ident, &ii.generics, None, Some(ty));
             }
         }
-        self.ann.post(self, AnnNode::SubItem(ii.hir_id))
+        self.ann.post(self, AnnNode::SubItem(ii.hir_id()))
     }
 
     pub fn print_local(&mut self, init: Option<&hir::Expr<'_>>, decl: impl Fn(&mut Self)) {

compiler/rustc_incremental/src/assert_dep_graph.rs

@@ -177,7 +177,7 @@ impl Visitor<'tcx> for IfThisChanged<'tcx> {
     }
 
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
-        self.process_attrs(impl_item.hir_id, &impl_item.attrs);
+        self.process_attrs(impl_item.hir_id(), &impl_item.attrs);
         intravisit::walk_impl_item(self, impl_item);
     }
 

compiler/rustc_incremental/src/persist/dirty_clean.rs

@@ -458,7 +458,7 @@ impl ItemLikeVisitor<'tcx> for DirtyCleanVisitor<'tcx> {
     }
 
     fn visit_impl_item(&mut self, item: &hir::ImplItem<'_>) {
-        self.check_item(item.hir_id, item.span);
+        self.check_item(item.hir_id(), item.span);
     }
 
     fn visit_foreign_item(&mut self, item: &hir::ForeignItem<'_>) {

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

@@ -7,9 +7,7 @@ use crate::traits::{ObligationCauseCode, UnifyReceiverContext};
 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorReported};
 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, TyKind,
-};
+use rustc_hir::{self as hir, GenericBound, Item, ItemKind, Lifetime, LifetimeName, Node, TyKind};
 use rustc_middle::ty::{self, AssocItemContainer, RegionKind, Ty, TypeFoldable, TypeVisitor};
 use rustc_span::symbol::Ident;
 use rustc_span::{MultiSpan, Span};
@@ -342,12 +340,12 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     ) -> Option<(Ident, &'tcx hir::Ty<'tcx>)> {
         let tcx = self.tcx();
         match tcx.hir().get_if_local(def_id) {
-            Some(Node::ImplItem(ImplItem { ident, hir_id, .. })) => {
-                match tcx.hir().find(tcx.hir().get_parent_item(*hir_id)) {
+            Some(Node::ImplItem(impl_item)) => {
+                match tcx.hir().find(tcx.hir().get_parent_item(impl_item.hir_id())) {
                     Some(Node::Item(Item {
                         kind: ItemKind::Impl(hir::Impl { self_ty, .. }),
                         ..
-                    })) => Some((*ident, self_ty)),
+                    })) => Some((impl_item.ident, self_ty)),
                     _ => None,
                 }
             }

compiler/rustc_lint/src/builtin.rs

@@ -600,7 +600,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
                     if let Some(Node::Item(item)) = cx.tcx.hir().find(hir_id) {
                         if let hir::VisibilityKind::Inherited = item.vis.node {
                             for impl_item_ref in items {
-                                self.private_traits.insert(impl_item_ref.id.hir_id);
+                                self.private_traits.insert(impl_item_ref.id.hir_id());
                             }
                         }
                     }
@@ -644,15 +644,14 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
 
     fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
         // If the method is an impl for a trait, don't doc.
-        if method_context(cx, impl_item.hir_id) == MethodLateContext::TraitImpl {
+        if method_context(cx, impl_item.hir_id()) == MethodLateContext::TraitImpl {
             return;
         }
 
-        let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
-        let (article, desc) = cx.tcx.article_and_description(def_id.to_def_id());
+        let (article, desc) = cx.tcx.article_and_description(impl_item.def_id.to_def_id());
         self.check_missing_docs_attrs(
             cx,
-            Some(impl_item.hir_id),
+            Some(impl_item.hir_id()),
             &impl_item.attrs,
             impl_item.span,
             article,
@@ -1378,7 +1377,7 @@ impl<'tcx> LateLintPass<'tcx> for UnreachablePub {
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
-        self.perform_lint(cx, "item", impl_item.hir_id, &impl_item.vis, impl_item.span, false);
+        self.perform_lint(cx, "item", impl_item.hir_id(), &impl_item.vis, impl_item.span, false);
     }
 }
 

compiler/rustc_lint/src/late.rs

@@ -314,8 +314,8 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         let generics = self.context.generics.take();
         self.context.generics = Some(&impl_item.generics);
-        self.with_lint_attrs(impl_item.hir_id, &impl_item.attrs, |cx| {
-            cx.with_param_env(impl_item.hir_id, |cx| {
+        self.with_lint_attrs(impl_item.hir_id(), &impl_item.attrs, |cx| {
+            cx.with_param_env(impl_item.hir_id(), |cx| {
                 lint_callback!(cx, check_impl_item, impl_item);
                 hir_visit::walk_impl_item(cx, impl_item);
                 lint_callback!(cx, check_impl_item_post, impl_item);