Use Arena inside hir::TraitItem.

Author: cjgillot

src/librustc/hir/check_attr.rs

@@ -107,7 +107,7 @@ impl Target {
         }
     }
 
-    fn from_trait_item(trait_item: &TraitItem) -> Target {
+    fn from_trait_item(trait_item: &TraitItem<'_>) -> Target {
         match trait_item.kind {
             TraitItemKind::Const(..) => Target::AssocConst,
             TraitItemKind::Method(_, hir::TraitMethod::Required(_)) => {
@@ -498,7 +498,7 @@ impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         intravisit::walk_item(self, item)
     }
 
-    fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem) {
+    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);
         intravisit::walk_trait_item(self, trait_item)

src/librustc/hir/intravisit.rs

@@ -295,7 +295,7 @@ pub trait Visitor<'v>: Sized {
     fn visit_use(&mut self, path: &'v Path, hir_id: HirId) {
         walk_use(self, path, hir_id)
     }
-    fn visit_trait_item(&mut self, ti: &'v TraitItem) {
+    fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
         walk_trait_item(self, ti)
     }
     fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
@@ -849,9 +849,9 @@ pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
     visitor.visit_nested_body(body_id)
 }
 
-pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
+pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
     visitor.visit_ident(trait_item.ident);
-    walk_list!(visitor, visit_attribute, &trait_item.attrs);
+    walk_list!(visitor, visit_attribute, trait_item.attrs);
     visitor.visit_generics(&trait_item.generics);
     match trait_item.kind {
         TraitItemKind::Const(ref ty, default) => {

src/librustc/hir/itemlikevisit.rs

@@ -46,7 +46,7 @@ use super::intravisit::Visitor;
 /// needed.
 pub trait ItemLikeVisitor<'hir> {
     fn visit_item(&mut self, item: &'hir Item<'hir>);
-    fn visit_trait_item(&mut self, trait_item: &'hir TraitItem);
+    fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>);
     fn visit_impl_item(&mut self, impl_item: &'hir ImplItem);
 }
 
@@ -69,7 +69,7 @@ impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
         self.visitor.visit_item(item);
     }
 
-    fn visit_trait_item(&mut self, trait_item: &'hir TraitItem) {
+    fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) {
         self.visitor.visit_trait_item(trait_item);
     }
 
@@ -81,7 +81,7 @@ impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
 /// A parallel variant of `ItemLikeVisitor`.
 pub trait ParItemLikeVisitor<'hir> {
     fn visit_item(&self, item: &'hir Item<'hir>);
-    fn visit_trait_item(&self, trait_item: &'hir TraitItem);
+    fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>);
     fn visit_impl_item(&self, impl_item: &'hir ImplItem);
 }
 
@@ -99,7 +99,7 @@ impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
         self.0.into_visitor().visit_item(item);
     }
 
-    fn visit_trait_item(&self, trait_item: &'hir TraitItem) {
+    fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
         self.0.into_visitor().visit_trait_item(trait_item);
     }
 

src/librustc/hir/lowering.rs

@@ -97,7 +97,7 @@ pub struct LoweringContext<'a, 'hir: 'a> {
     /// The items being lowered are collected here.
     items: BTreeMap<hir::HirId, hir::Item<'hir>>,
 
-    trait_items: BTreeMap<hir::TraitItemId, hir::TraitItem>,
+    trait_items: BTreeMap<hir::TraitItemId, hir::TraitItem<'hir>>,
     impl_items: BTreeMap<hir::ImplItemId, hir::ImplItem>,
     bodies: BTreeMap<hir::BodyId, hir::Body>,
     exported_macros: Vec<hir::MacroDef<'hir>>,

src/librustc/hir/lowering/item.rs

@@ -816,14 +816,14 @@ impl LoweringContext<'_, 'hir> {
         }
     }
 
-    fn lower_trait_item(&mut self, i: &AssocItem) -> hir::TraitItem {
+    fn lower_trait_item(&mut self, i: &AssocItem) -> hir::TraitItem<'hir> {
         let trait_item_def_id = self.resolver.definitions().local_def_id(i.id);
 
         let (generics, kind) = match i.kind {
             AssocItemKind::Const(ref ty, ref default) => (
                 self.lower_generics(&i.generics, ImplTraitContext::disallowed()),
                 hir::TraitItemKind::Const(
-                    self.lower_ty(ty, ImplTraitContext::disallowed()),
+                    self.arena.alloc(self.lower_ty(ty, ImplTraitContext::disallowed()).into_inner()),
                     default
                         .as_ref()
                         .map(|x| self.lower_const_body(i.span, Some(x))),
@@ -852,12 +852,13 @@ impl LoweringContext<'_, 'hir> {
                 (generics, hir::TraitItemKind::Method(sig, hir::TraitMethod::Provided(body_id)))
             }
             AssocItemKind::TyAlias(ref bounds, ref default) => {
+                let ty = default.as_ref().map(|x| -> &'hir hir::Ty { self.arena.alloc(
+                        self.lower_ty(x, ImplTraitContext::disallowed()).into_inner())
+                });
                 let generics = self.lower_generics(&i.generics, ImplTraitContext::disallowed());
                 let kind = hir::TraitItemKind::Type(
                     self.lower_param_bounds(bounds, ImplTraitContext::disallowed()),
-                    default
-                        .as_ref()
-                        .map(|x| self.lower_ty(x, ImplTraitContext::disallowed())),
+                    ty,
                 );
 
                 (generics, kind)
@@ -868,7 +869,7 @@ impl LoweringContext<'_, 'hir> {
         hir::TraitItem {
             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,
             kind,
             span: i.span,

src/librustc/hir/map/blocks.rs

@@ -53,7 +53,7 @@ impl MaybeFnLike for ast::ImplItem {
     }
 }
 
-impl MaybeFnLike for ast::TraitItem {
+impl MaybeFnLike for ast::TraitItem<'_> {
     fn is_fn_like(&self) -> bool {
         match self.kind {
             ast::TraitItemKind::Method(_, ast::TraitMethod::Provided(_)) => true,

src/librustc/hir/map/collector.rs

@@ -398,7 +398,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         intravisit::walk_generic_param(self, param);
     }
 
-    fn visit_trait_item(&mut self, ti: &'hir TraitItem) {
+    fn visit_trait_item(&mut self, ti: &'hir TraitItem<'hir>) {
         debug_assert_eq!(ti.hir_id.owner,
                          self.definitions.opt_def_index(self.hir_to_node_id[&ti.hir_id]).unwrap());
         self.with_dep_node_owner(ti.hir_id.owner, ti, |this| {

src/librustc/hir/map/hir_id_validator.rs

@@ -58,7 +58,7 @@ impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
         inner_visitor.check(i.hir_id, |this| intravisit::walk_item(this, i));
     }
 
-    fn visit_trait_item(&mut self, i: &'hir hir::TraitItem) {
+    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));
     }

src/librustc/hir/map/mod.rs

@@ -443,7 +443,7 @@ impl<'hir> Map<'hir> {
         self.forest.krate()
     }
 
-    pub fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem {
+    pub fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
         self.read(id.hir_id);
 
         // N.B., intentionally bypass `self.forest.krate()` so that we
@@ -973,7 +973,7 @@ impl<'hir> Map<'hir> {
         }
     }
 
-    pub fn expect_trait_item(&self, id: HirId) -> &'hir TraitItem {
+    pub fn expect_trait_item(&self, id: HirId) -> &'hir TraitItem<'hir> {
         match self.find(id) {
             Some(Node::TraitItem(item)) => item,
             _ => bug!("expected trait item, found {}", self.node_to_string(id))
@@ -1252,7 +1252,7 @@ impl Named for Item<'_> { fn name(&self) -> Name { self.ident.name } }
 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 TraitItem<'_> { 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,

src/librustc/hir/mod.rs

@@ -758,7 +758,7 @@ pub struct Crate<'hir> {
     // slightly different results.
     pub items: BTreeMap<HirId, Item<'hir>>,
 
-    pub trait_items: BTreeMap<TraitItemId, TraitItem>,
+    pub trait_items: BTreeMap<TraitItemId, TraitItem<'hir>>,
     pub impl_items: BTreeMap<ImplItemId, ImplItem>,
     pub bodies: BTreeMap<BodyId, Body>,
     pub trait_impls: BTreeMap<DefId, Vec<HirId>>,
@@ -779,7 +779,7 @@ impl Crate<'hir> {
         &self.items[&id]
     }
 
-    pub fn trait_item(&self, id: TraitItemId) -> &TraitItem {
+    pub fn trait_item(&self, id: TraitItemId) -> &TraitItem<'hir> {
         &self.trait_items[&id]
     }
 
@@ -1897,12 +1897,12 @@ pub struct TraitItemId {
 /// either required (meaning it doesn't have an implementation, just a
 /// signature) or provided (meaning it has a default implementation).
 #[derive(RustcEncodable, RustcDecodable, Debug)]
-pub struct TraitItem {
+pub struct TraitItem<'hir> {
     pub ident: Ident,
     pub hir_id: HirId,
-    pub attrs: HirVec<Attribute>,
+    pub attrs: &'hir [Attribute],
     pub generics: Generics,
-    pub kind: TraitItemKind,
+    pub kind: TraitItemKind<'hir>,
     pub span: Span,
 }
 
@@ -1918,14 +1918,14 @@ pub enum TraitMethod {
 
 /// Represents a trait method or associated constant or type
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
-pub enum TraitItemKind {
+pub enum TraitItemKind<'hir> {
     /// An associated constant with an optional value (otherwise `impl`s must contain a value).
-    Const(P<Ty>, Option<BodyId>),
+    Const(&'hir Ty, Option<BodyId>),
     /// A method with an optional body.
     Method(FnSig, TraitMethod),
     /// An associated type with (possibly empty) bounds and optional concrete
     /// type.
-    Type(GenericBounds, Option<P<Ty>>),
+    Type(GenericBounds, Option<&'hir Ty>),
 }
 
 // The bodies for items are stored "out of line", in a separate
@@ -2789,7 +2789,7 @@ pub enum Node<'hir> {
     Param(&'hir Param),
     Item(&'hir Item<'hir>),
     ForeignItem(&'hir ForeignItem<'hir>),
-    TraitItem(&'hir TraitItem),
+    TraitItem(&'hir TraitItem<'hir>),
     ImplItem(&'hir ImplItem),
     Variant(&'hir Variant),
     Field(&'hir StructField),