make distinct Hir() nodes in the graph for impl items

Author: nikomatsakis

src/librustc/dep_graph/visit.rs

@@ -47,13 +47,12 @@ pub fn visit_all_item_likes_in_krate<'a, 'tcx, V, F>(tcx: TyCtxt<'a, 'tcx, 'tcx>
         }
 
         fn visit_impl_item(&mut self, i: &'tcx hir::ImplItem) {
-            // TODO -- use the def-id of the impl for now
-            let impl_def_id = self.tcx.map.get_parent_did(i.id);
-            let task_id = (self.dep_node_fn)(impl_def_id);
+            let impl_item_def_id = self.tcx.map.local_def_id(i.id);
+            let task_id = (self.dep_node_fn)(impl_item_def_id);
             let _task = self.tcx.dep_graph.in_task(task_id.clone());
             debug!("Started task {:?}", task_id);
-            assert!(!self.tcx.map.is_inlined_def_id(impl_def_id));
-            self.tcx.dep_graph.read(DepNode::Hir(impl_def_id));
+            assert!(!self.tcx.map.is_inlined_def_id(impl_item_def_id));
+            self.tcx.dep_graph.read(DepNode::Hir(impl_item_def_id));
             self.visitor.visit_impl_item(i);
             debug!("Ended task {:?}", task_id);
         }

src/librustc/hir/map/mod.rs

@@ -254,9 +254,14 @@ impl<'ast> Map<'ast> {
                         return DepNode::Hir(def_id);
                     }
 
+                    EntryImplItem(..) => {
+                        let def_id = self.local_def_id(id);
+                        assert!(!self.is_inlined_def_id(def_id));
+                        return DepNode::Hir(def_id);
+                    }
+
                     EntryForeignItem(p, _) |
                     EntryTraitItem(p, _) |
-                    EntryImplItem(p, _) |
                     EntryVariant(p, _) |
                     EntryExpr(p, _) |
                     EntryStmt(p, _) |
@@ -379,7 +384,6 @@ impl<'ast> Map<'ast> {
     }
 
     pub fn impl_item(&self, id: ImplItemId) -> &'ast ImplItem {
-        // TODO right now this triggers a read of the whole impl
         self.read(id.id);
 
         // NB: intentionally bypass `self.forest.krate()` so that we

src/librustc_incremental/calculate_svh/mod.rs

@@ -207,6 +207,11 @@ impl<'a, 'tcx> Visitor<'tcx> for HashItemsVisitor<'a, 'tcx> {
         visit::walk_item(self, item);
     }
 
+    fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+        self.calculate_node_id(impl_item.id, |v| v.visit_impl_item(impl_item));
+        visit::walk_impl_item(self, impl_item);
+    }
+
     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem) {
         self.calculate_node_id(item.id, |v| v.visit_foreign_item(item));
         visit::walk_foreign_item(self, item);

src/librustc_incremental/calculate_svh/svh_visitor.rs

@@ -503,10 +503,8 @@ impl<'a, 'hash, 'tcx> visit::Visitor<'tcx> for StrictVersionHashVisitor<'a, 'has
         // Each item is hashed independently; ignore nested items.
     }
 
-    fn visit_nested_impl_item(&mut self, impl_item_id: ImplItemId) {
-        // For now, we hash impl items as part of the containing impl.
-        let impl_item = self.tcx.map.impl_item(impl_item_id);
-        self.visit_impl_item(impl_item);
+    fn visit_nested_impl_item(&mut self, _: ImplItemId) {
+        // Impl items are hashed independently; ignore nested impl items.
     }
 
     fn visit_variant_data(&mut self,