Use Arena inside hir::ImplItem.

src/librustc/hir/check_attr.rs

@@ -128,7 +128,7 @@ impl Target {
         }
     }
 
-    fn from_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item: &hir::ImplItem) -> Target {
+    fn from_impl_item<'tcx>(tcx: TyCtxt<'tcx>, impl_item: &hir::ImplItem<'_>) -> Target {
         match impl_item.kind {
             hir::ImplItemKind::Const(..) => Target::AssocConst,
             hir::ImplItemKind::Method(..) => {
@@ -510,7 +510,7 @@ impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         intravisit::walk_foreign_item(self, f_item)
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         let target = Target::from_impl_item(self.tcx, impl_item);
         self.check_attributes(impl_item.hir_id, &impl_item.attrs, &impl_item.span, target, None);
         intravisit::walk_impl_item(self, impl_item)

src/librustc/hir/intravisit.rs

@@ -301,7 +301,7 @@ pub trait Visitor<'v>: Sized {
     fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
         walk_trait_item_ref(self, ii)
     }
-    fn visit_impl_item(&mut self, ii: &'v ImplItem) {
+    fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
         walk_impl_item(self, ii)
     }
     fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
@@ -893,14 +893,14 @@ pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref:
     visitor.visit_defaultness(defaultness);
 }
 
-pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
+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: _,
         ident,
         ref vis,
         ref defaultness,
-        ref attrs,
+        attrs,
         ref generics,
         ref kind,
         span: _,

src/librustc/hir/itemlikevisit.rs

@@ -47,7 +47,7 @@ use super::intravisit::Visitor;
 pub trait ItemLikeVisitor<'hir> {
     fn visit_item(&mut self, item: &'hir Item<'hir>);
     fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>);
-    fn visit_impl_item(&mut self, impl_item: &'hir ImplItem);
+    fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>);
 }
 
 pub struct DeepVisitor<'v, V> {
@@ -73,7 +73,7 @@ impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
         self.visitor.visit_trait_item(trait_item);
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'hir ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) {
         self.visitor.visit_impl_item(impl_item);
     }
 }
@@ -82,7 +82,7 @@ impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
 pub trait ParItemLikeVisitor<'hir> {
     fn visit_item(&self, item: &'hir Item<'hir>);
     fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>);
-    fn visit_impl_item(&self, impl_item: &'hir ImplItem);
+    fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>);
 }
 
 pub trait IntoVisitor<'hir> {
@@ -103,7 +103,7 @@ impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
         self.0.into_visitor().visit_trait_item(trait_item);
     }
 
-    fn visit_impl_item(&self, impl_item: &'hir ImplItem) {
+    fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
         self.0.into_visitor().visit_impl_item(impl_item);
     }
 }

src/librustc/hir/lowering.rs

@@ -98,7 +98,7 @@ pub struct LoweringContext<'a, 'hir: 'a> {
     items: BTreeMap<hir::HirId, hir::Item<'hir>>,
 
     trait_items: BTreeMap<hir::TraitItemId, hir::TraitItem<'hir>>,
-    impl_items: BTreeMap<hir::ImplItemId, hir::ImplItem>,
+    impl_items: BTreeMap<hir::ImplItemId, hir::ImplItem<'hir>>,
     bodies: BTreeMap<hir::BodyId, hir::Body>,
     exported_macros: Vec<hir::MacroDef<'hir>>,
     non_exported_macro_attrs: Vec<ast::Attribute>,

src/librustc/hir/lowering/item.rs

@@ -906,14 +906,14 @@ impl LoweringContext<'_, 'hir> {
         self.expr(span, hir::ExprKind::Err, AttrVec::new())
     }
 
-    fn lower_impl_item(&mut self, i: &AssocItem) -> hir::ImplItem {
+    fn lower_impl_item(&mut self, i: &AssocItem) -> hir::ImplItem<'hir> {
         let impl_item_def_id = self.resolver.definitions().local_def_id(i.id);
 
         let (generics, kind) = match i.kind {
             AssocItemKind::Const(ref ty, ref expr) => (
                 self.lower_generics(&i.generics, ImplTraitContext::disallowed()),
                 hir::ImplItemKind::Const(
-                    self.lower_ty(ty, ImplTraitContext::disallowed()),
+                    self.arena.alloc(self.lower_ty(ty, ImplTraitContext::disallowed()).into_inner()),
                     self.lower_const_body(i.span, expr.as_deref()),
                 ),
             ),
@@ -940,11 +940,13 @@ impl LoweringContext<'_, 'hir> {
                 let generics = self.lower_generics(&i.generics, ImplTraitContext::disallowed());
                 let kind = match ty {
                     None => {
-                        hir::ImplItemKind::TyAlias(P(self.ty(i.span, hir::TyKind::Err)))
+                        let ty = self.arena.alloc(self.ty(i.span, hir::TyKind::Err));
+                        hir::ImplItemKind::TyAlias(ty)
                     }
                     Some(ty) => match ty.kind.opaque_top_hack() {
                         None => {
                             let ty = self.lower_ty(ty, ImplTraitContext::disallowed());
+                            let ty = self.arena.alloc(ty.into_inner());
                             hir::ImplItemKind::TyAlias(ty)
                         }
                         Some(bs) => {
@@ -961,7 +963,7 @@ impl LoweringContext<'_, 'hir> {
         hir::ImplItem {
             hir_id: self.lower_node_id(i.id),
             ident: i.ident,
-            attrs: self.lower_attrs(&i.attrs),
+            attrs: self.lower_attrs_arena(&i.attrs),
             generics,
             vis: self.lower_visibility(&i.vis, None),
             defaultness: self.lower_defaultness(i.defaultness, true /* [1] */),

src/librustc/hir/map/blocks.rs

@@ -44,7 +44,7 @@ impl MaybeFnLike for ast::Item<'_> {
     }
 }
 
-impl MaybeFnLike for ast::ImplItem {
+impl MaybeFnLike for ast::ImplItem<'_> {
     fn is_fn_like(&self) -> bool {
         match self.kind {
             ast::ImplItemKind::Method(..) => true,

src/librustc/hir/map/collector.rs

@@ -410,7 +410,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
-    fn visit_impl_item(&mut self, ii: &'hir ImplItem) {
+    fn visit_impl_item(&mut self, ii: &'hir ImplItem<'hir>) {
         debug_assert_eq!(ii.hir_id.owner,
                          self.definitions.opt_def_index(self.hir_to_node_id[&ii.hir_id]).unwrap());
         self.with_dep_node_owner(ii.hir_id.owner, ii, |this| {

src/librustc/hir/map/hir_id_validator.rs

@@ -63,7 +63,7 @@ impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
         inner_visitor.check(i.hir_id, |this| intravisit::walk_trait_item(this, i));
     }
 
-    fn visit_impl_item(&mut self, i: &'hir hir::ImplItem) {
+    fn visit_impl_item(&mut self, i: &'hir hir::ImplItem<'hir>) {
         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
         inner_visitor.check(i.hir_id, |this| intravisit::walk_impl_item(this, i));
     }

src/librustc/hir/map/mod.rs

@@ -451,7 +451,7 @@ impl<'hir> Map<'hir> {
         self.forest.krate.trait_item(id)
     }
 
-    pub fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem {
+    pub fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
         self.read(id.hir_id);
 
         // N.B., intentionally bypass `self.forest.krate()` so that we
@@ -966,7 +966,7 @@ impl<'hir> Map<'hir> {
         }
     }
 
-    pub fn expect_impl_item(&self, id: HirId) -> &'hir ImplItem {
+    pub fn expect_impl_item(&self, id: HirId) -> &'hir ImplItem<'hir> {
         match self.find(id) {
             Some(Node::ImplItem(item)) => item,
             _ => bug!("expected impl item, found {}", self.node_to_string(id))
@@ -1253,7 +1253,7 @@ impl Named for ForeignItem<'_> { fn name(&self) -> Name { self.ident.name } }
 impl Named for Variant { fn name(&self) -> Name { self.ident.name } }
 impl Named for StructField { fn name(&self) -> Name { self.ident.name } }
 impl Named for TraitItem<'_> { fn name(&self) -> Name { self.ident.name } }
-impl Named for ImplItem { fn name(&self) -> Name { self.ident.name } }
+impl Named for ImplItem<'_> { fn name(&self) -> Name { self.ident.name } }
 
 pub fn map_crate<'hir>(sess: &crate::session::Session,
                        cstore: &CrateStoreDyn,

src/librustc/hir/mod.rs

@@ -759,7 +759,7 @@ pub struct Crate<'hir> {
     pub items: BTreeMap<HirId, Item<'hir>>,
 
     pub trait_items: BTreeMap<TraitItemId, TraitItem<'hir>>,
-    pub impl_items: BTreeMap<ImplItemId, ImplItem>,
+    pub impl_items: BTreeMap<ImplItemId, ImplItem<'hir>>,
     pub bodies: BTreeMap<BodyId, Body>,
     pub trait_impls: BTreeMap<DefId, Vec<HirId>>,
 
@@ -783,7 +783,7 @@ impl Crate<'hir> {
         &self.trait_items[&id]
     }
 
-    pub fn impl_item(&self, id: ImplItemId) -> &ImplItem {
+    pub fn impl_item(&self, id: ImplItemId) -> &ImplItem<'hir> {
         &self.impl_items[&id]
     }
 
@@ -1938,27 +1938,27 @@ pub struct ImplItemId {
 
 /// Represents anything within an `impl` block.
 #[derive(RustcEncodable, RustcDecodable, Debug)]
-pub struct ImplItem {
+pub struct ImplItem<'hir> {
     pub ident: Ident,
     pub hir_id: HirId,
     pub vis: Visibility,
     pub defaultness: Defaultness,
-    pub attrs: HirVec<Attribute>,
+    pub attrs: &'hir [Attribute],
     pub generics: Generics,
-    pub kind: ImplItemKind,
+    pub kind: ImplItemKind<'hir>,
     pub span: Span,
 }
 
 /// Represents various kinds of content within an `impl`.
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
-pub enum ImplItemKind {
+pub enum ImplItemKind<'hir> {
     /// An associated constant of the given type, set to the constant result
     /// of the expression.
-    Const(P<Ty>, BodyId),
+    Const(&'hir Ty, BodyId),
     /// A method implementation with the given signature and body.
     Method(FnSig, BodyId),
     /// An associated type.
-    TyAlias(P<Ty>),
+    TyAlias(&'hir Ty),
     /// An associated `type = impl Trait`.
     OpaqueTy(GenericBounds),
 }
@@ -2790,7 +2790,7 @@ pub enum Node<'hir> {
     Item(&'hir Item<'hir>),
     ForeignItem(&'hir ForeignItem<'hir>),
     TraitItem(&'hir TraitItem<'hir>),
-    ImplItem(&'hir ImplItem),
+    ImplItem(&'hir ImplItem<'hir>),
     Variant(&'hir Variant),
     Field(&'hir StructField),
     AnonConst(&'hir AnonConst),

src/librustc/hir/print.rs

@@ -882,7 +882,7 @@ impl<'a> State<'a> {
         self.ann.post(self, AnnNode::SubItem(ti.hir_id))
     }
 
-    pub fn print_impl_item(&mut self, ii: &hir::ImplItem) {
+    pub fn print_impl_item(&mut self, ii: &hir::ImplItem<'_>) {
         self.ann.pre(self, AnnNode::SubItem(ii.hir_id));
         self.hardbreak_if_not_bol();
         self.maybe_print_comment(ii.span.lo());

src/librustc/ich/impls_hir.rs

@@ -172,7 +172,7 @@ impl<'a> HashStable<StableHashingContext<'a>> for hir::TraitItem<'_> {
 }
 
 
-impl<'a> HashStable<StableHashingContext<'a>> for hir::ImplItem {
+impl<'a> HashStable<StableHashingContext<'a>> for hir::ImplItem<'_> {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         let hir::ImplItem {
             hir_id: _,

src/librustc/infer/error_reporting/mod.rs

@@ -271,7 +271,7 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
-    fn impl_item_scope_tag(item: &hir::ImplItem) -> &'static str {
+    fn impl_item_scope_tag(item: &hir::ImplItem<'_>) -> &'static str {
         match item.kind {
             hir::ImplItemKind::Method(..) => "method body",
             hir::ImplItemKind::Const(..)

src/librustc/lint/context.rs

@@ -1085,7 +1085,7 @@ for LateContextAndPass<'a, 'tcx, T> {
         self.context.generics = generics;
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+    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| {

src/librustc/lint/mod.rs

@@ -126,8 +126,8 @@ macro_rules! late_lint_methods {
             );
             fn check_trait_item(a: &$hir hir::TraitItem<$hir>);
             fn check_trait_item_post(a: &$hir hir::TraitItem<$hir>);
-            fn check_impl_item(a: &$hir hir::ImplItem);
-            fn check_impl_item_post(a: &$hir hir::ImplItem);
+            fn check_impl_item(a: &$hir hir::ImplItem<$hir>);
+            fn check_impl_item_post(a: &$hir hir::ImplItem<$hir>);
             fn check_struct_def(a: &$hir hir::VariantData);
             fn check_struct_def_post(a: &$hir hir::VariantData);
             fn check_struct_field(a: &$hir hir::StructField);
@@ -655,7 +655,7 @@ impl intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> {
         });
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         self.with_lint_attrs(impl_item.hir_id, &impl_item.attrs, |builder| {
             intravisit::walk_impl_item(builder, impl_item);
         });

src/librustc/middle/diagnostic_items.rs

@@ -33,7 +33,7 @@ impl<'v, 'tcx> ItemLikeVisitor<'v> for DiagnosticItemCollector<'tcx> {
         self.observe_item(&trait_item.attrs, trait_item.hir_id);
     }
 
-    fn visit_impl_item(&mut self, impl_item: &hir::ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {
         self.observe_item(&impl_item.attrs, impl_item.hir_id);
     }
 }

src/librustc/middle/lang_items.rs

@@ -155,7 +155,7 @@ impl ItemLikeVisitor<'v> for LanguageItemCollector<'tcx> {
         // At present, lang items are always items, not trait items.
     }
 
-    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
+    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {
         // At present, lang items are always items, not impl items.
     }
 }

src/librustc/middle/reachable.rs

@@ -47,7 +47,7 @@ fn item_might_be_inlined(tcx: TyCtxt<'tcx>, item: &hir::Item<'_>, attrs: Codegen
 
 fn method_might_be_inlined(
     tcx: TyCtxt<'_>,
-    impl_item: &hir::ImplItem,
+    impl_item: &hir::ImplItem<'_>,
     impl_src: DefId,
 ) -> bool {
     let codegen_fn_attrs = tcx.codegen_fn_attrs(impl_item.hir_id.owner_def_id());
@@ -389,7 +389,7 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx
 
     fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {}
 
-    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
+    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {
         // processed in visit_item above
     }
 }

src/librustc/middle/resolve_lifetime.rs

@@ -823,7 +823,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         use self::hir::ImplItemKind::*;
         match impl_item.kind {
             Method(ref sig, _) => {

src/librustc/middle/stability.rs

@@ -289,7 +289,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
         });
     }
 
-    fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) {
         let kind = if self.in_trait_impl {
             AnnotationKind::Prohibited
         } else {
@@ -373,7 +373,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'a, 'tcx> {
         intravisit::walk_trait_item(self, ti);
     }
 
-    fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) {
         let impl_def_id = self.tcx.hir().local_def_id(
             self.tcx.hir().get_parent_item(ii.hir_id));
         if self.tcx.impl_trait_ref(impl_def_id).is_none() {

src/librustc_codegen_utils/symbol_names_test.rs

@@ -65,7 +65,7 @@ impl hir::itemlikevisit::ItemLikeVisitor<'tcx> for SymbolNamesTest<'tcx> {
         self.process_attrs(trait_item.hir_id);
     }
 
-    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         self.process_attrs(impl_item.hir_id);
     }
 }

src/librustc_incremental/assert_dep_graph.rs

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

src/librustc_incremental/persist/dirty_clean.rs

@@ -540,7 +540,7 @@ impl ItemLikeVisitor<'tcx> for DirtyCleanVisitor<'tcx> {
         self.check_item(item.hir_id, item.span);
     }
 
-    fn visit_impl_item(&mut self, item: &hir::ImplItem) {
+    fn visit_impl_item(&mut self, item: &hir::ImplItem<'_>) {
         self.check_item(item.hir_id, item.span);
     }
 }

src/librustc_interface/proc_macro_decls.rs

@@ -33,7 +33,7 @@ impl<'v> ItemLikeVisitor<'v> for Finder {
     fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {
     }
 
-    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem) {
+    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {
     }
 }