Better typing and type verification

src/compiler/graph.cc

Index: src/compiler/graph.cc
diff --git a/src/compiler/graph.cc b/src/compiler/graph.cc
index 3f47eace8159e9d7ef97566db8bfe39a1e1acc8c..a0ec171aba77668a53076c7981970267da4786d2 100644
--- a/src/compiler/graph.cc
+++ b/src/compiler/graph.cc
@@ -20,17 +20,26 @@ namespace compiler {
 
 Graph::Graph(Zone* zone)
     : GenericGraph<Node>(zone),
-      decorators_(DecoratorVector::allocator_type(zone)) {}
+      decorators_(DecoratorVector::allocator_type(zone)),
+      is_typed_(false) {}
+
+
+void Graph::Decorate(Node* node) {
+  for (DecoratorVector::iterator i = decorators_.begin();
+       i != decorators_.end(); ++i) {
+    (*i)->Decorate(node);
+  }
+  // Iff the graph is typed, then there _must_ be a decorator to type new nodes.
+  DCHECK(NodeProperties::IsTyped(node) ==
+         (is_typed_ && OperatorProperties::HasValueOutput(node->op())));
+}
 
 
 Node* Graph::NewNode(Operator* op, int input_count, Node** inputs) {
   DCHECK(op->InputCount() <= input_count);
   Node* result = Node::New(this, input_count, inputs);
   result->Initialize(op);
-  for (DecoratorVector::iterator i = decorators_.begin();
-       i != decorators_.end(); ++i) {
-    (*i)->Decorate(result);
-  }
+  Decorate(result);
   return result;
 }