hir: remove parent_node from NodeCollector

Author: ljedrz

src/librustc/hir/map/collector.rs

@@ -27,8 +27,6 @@ pub(super) struct NodeCollector<'a, 'hir> {
     /// The node map
     map: Vec<Option<Entry<'hir>>>,
     /// The parent of this node
-    parent_node: NodeId,
-
     parent_hir: hir::HirId,
 
     // These fields keep track of the currently relevant DepNodes during
@@ -149,7 +147,6 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
             krate,
             source_map: sess.source_map(),
             map: repeat(None).take(sess.current_node_id_count()).collect(),
-            parent_node: CRATE_NODE_ID,
             parent_hir: hir::CRATE_HIR_ID,
             current_signature_dep_index: root_mod_sig_dep_index,
             current_full_dep_index: root_mod_full_dep_index,
@@ -233,7 +230,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 
     fn insert(&mut self, span: Span, hir_id: HirId, node: Node<'hir>) {
         let entry = Entry {
-            parent: self.parent_node,
+            parent: self.hir_to_node_id[&self.parent_hir],
             parent_hir: self.parent_hir,
             dep_node: if self.currently_in_body {
                 self.current_full_dep_index
@@ -286,17 +283,13 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 
     fn with_parent<F: FnOnce(&mut Self)>(
         &mut self,
-        parent_node_id: NodeId,
         parent_hir_id: HirId,
         f: F,
     ) {
-        let parent_node = self.parent_node;
-        self.parent_node = parent_node_id;
         let parent_hir = self.parent_hir;
         self.parent_hir = parent_hir_id;
         f(self);
         self.parent_hir = parent_hir;
-        self.parent_node = parent_node;
     }
 
     fn with_dep_node_owner<T: for<'b> HashStable<StableHashingContext<'b>>,
@@ -366,7 +359,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
                          self.definitions.opt_def_index(i.id).unwrap());
         self.with_dep_node_owner(i.hir_id.owner, i, |this| {
             this.insert(i.span, i.hir_id, Node::Item(i));
-            this.with_parent(i.id, i.hir_id, |this| {
+            this.with_parent(i.hir_id, |this| {
                 if let ItemKind::Struct(ref struct_def, _) = i.node {
                     // If this is a tuple-like struct, register the constructor.
                     if !struct_def.is_struct() {
@@ -381,7 +374,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_foreign_item(&mut self, foreign_item: &'hir ForeignItem) {
         self.insert(foreign_item.span, foreign_item.hir_id, Node::ForeignItem(foreign_item));
 
-        self.with_parent(foreign_item.id, foreign_item.hir_id, |this| {
+        self.with_parent(foreign_item.hir_id, |this| {
             intravisit::walk_foreign_item(this, foreign_item);
         });
     }
@@ -397,7 +390,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         self.with_dep_node_owner(ti.hir_id.owner, ti, |this| {
             this.insert(ti.span, ti.hir_id, Node::TraitItem(ti));
 
-            this.with_parent(ti.id, ti.hir_id, |this| {
+            this.with_parent(ti.hir_id, |this| {
                 intravisit::walk_trait_item(this, ti);
             });
         });
@@ -409,7 +402,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         self.with_dep_node_owner(ii.hir_id.owner, ii, |this| {
             this.insert(ii.span, ii.hir_id, Node::ImplItem(ii));
 
-            this.with_parent(ii.id, ii.hir_id, |this| {
+            this.with_parent(ii.hir_id, |this| {
                 intravisit::walk_impl_item(this, ii);
             });
         });
@@ -423,31 +416,31 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         };
         self.insert(pat.span, pat.hir_id, node);
 
-        self.with_parent(pat.id, pat.hir_id, |this| {
+        self.with_parent(pat.hir_id, |this| {
             intravisit::walk_pat(this, pat);
         });
     }
 
     fn visit_anon_const(&mut self, constant: &'hir AnonConst) {
         self.insert(DUMMY_SP, constant.hir_id, Node::AnonConst(constant));
 
-        self.with_parent(constant.id, constant.hir_id, |this| {
+        self.with_parent(constant.hir_id, |this| {
             intravisit::walk_anon_const(this, constant);
         });
     }
 
     fn visit_expr(&mut self, expr: &'hir Expr) {
         self.insert(expr.span, expr.hir_id, Node::Expr(expr));
 
-        self.with_parent(expr.id, expr.hir_id, |this| {
+        self.with_parent(expr.hir_id, |this| {
             intravisit::walk_expr(this, expr);
         });
     }
 
     fn visit_stmt(&mut self, stmt: &'hir Stmt) {
         self.insert(stmt.span, stmt.hir_id, Node::Stmt(stmt));
 
-        self.with_parent(stmt.id, stmt.hir_id, |this| {
+        self.with_parent(stmt.hir_id, |this| {
             intravisit::walk_stmt(this, stmt);
         });
     }
@@ -463,15 +456,15 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_ty(&mut self, ty: &'hir Ty) {
         self.insert(ty.span, ty.hir_id, Node::Ty(ty));
 
-        self.with_parent(ty.id, ty.hir_id, |this| {
+        self.with_parent(ty.hir_id, |this| {
             intravisit::walk_ty(this, ty);
         });
     }
 
     fn visit_trait_ref(&mut self, tr: &'hir TraitRef) {
         self.insert(tr.path.span, tr.hir_ref_id, Node::TraitRef(tr));
 
-        self.with_parent(tr.ref_id, tr.hir_ref_id, |this| {
+        self.with_parent(tr.hir_ref_id, |this| {
             intravisit::walk_trait_ref(this, tr);
         });
     }
@@ -484,14 +477,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
 
     fn visit_block(&mut self, block: &'hir Block) {
         self.insert(block.span, block.hir_id, Node::Block(block));
-        self.with_parent(block.id, block.hir_id, |this| {
+        self.with_parent(block.hir_id, |this| {
             intravisit::walk_block(this, block);
         });
     }
 
     fn visit_local(&mut self, l: &'hir Local) {
         self.insert(l.span, l.hir_id, Node::Local(l));
-        self.with_parent(l.id, l.hir_id, |this| {
+        self.with_parent(l.hir_id, |this| {
             intravisit::walk_local(this, l)
         })
     }
@@ -505,9 +498,9 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
             VisibilityKind::Public |
             VisibilityKind::Crate(_) |
             VisibilityKind::Inherited => {}
-            VisibilityKind::Restricted { id, hir_id, .. } => {
+            VisibilityKind::Restricted { hir_id, .. } => {
                 self.insert(visibility.span, hir_id, Node::Visibility(visibility));
-                self.with_parent(id, hir_id, |this| {
+                self.with_parent(hir_id, |this| {
                     intravisit::walk_vis(this, visibility);
                 });
             }
@@ -524,14 +517,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
 
     fn visit_variant(&mut self, v: &'hir Variant, g: &'hir Generics, item_id: HirId) {
         self.insert(v.span, v.node.data.hir_id(), Node::Variant(v));
-        self.with_parent(v.node.data.id(), v.node.data.hir_id(), |this| {
+        self.with_parent(v.node.data.hir_id(), |this| {
             intravisit::walk_variant(this, v, g, item_id);
         });
     }
 
     fn visit_struct_field(&mut self, field: &'hir StructField) {
         self.insert(field.span, field.hir_id, Node::Field(field));
-        self.with_parent(field.id, field.hir_id, |this| {
+        self.with_parent(field.hir_id, |this| {
             intravisit::walk_struct_field(this, field);
         });
     }