Use phase-local zone in the graph builder.

src/compiler/graph-builder.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_GRAPH_BUILDER_H_
 #define V8_COMPILER_GRAPH_BUILDER_H_
 
 #include "src/v8.h"
 
 #include "src/allocation.h"
@@ skipping 104 matching lines @@
   void set_environment(Environment* env) { environment_ = env; }
 
   Node* current_context() const { return current_context_; }
   void set_current_context(Node* context) { current_context_ = context; }
 
   Node* exit_control() const { return exit_control_; }
   void set_exit_control(Node* node) { exit_control_ = node; }
 
   Node* dead_control();
 
-  // TODO(mstarzinger): Use phase-local zone instead!
-  Zone* zone() const { return graph()->zone(); }
-  Isolate* isolate() const { return zone()->isolate(); }
+  Zone* graph_zone() const { return graph()->zone(); }
+  Zone* local_zone() { return &local_zone_; }
+  Isolate* isolate() const { return graph_zone()->isolate(); }
   CommonOperatorBuilder* common() const { return common_; }
 
   // Helper to wrap a Handle<T> into a Unique<T>.
   template <class T>
   Unique<T> MakeUnique(Handle<T> object) {
     return Unique<T>::CreateUninitialized(object);
   }
 
   // Support for control flow builders. The concrete type of the environment
   // depends on the graph builder, but environments themselves are not virtual.
   virtual Environment* CopyEnvironment(Environment* env);
 
   // Helper to indicate a node exits the function body.
   void UpdateControlDependencyToLeaveFunction(Node* exit);
 
  private:
   CommonOperatorBuilder* common_;
   Environment* environment_;
 
+  // Zone local to the builder for data not leaking into the graph.
+  Zone local_zone_;
+
   // Node representing the control dependency for dead code.
   SetOncePointer<Node> dead_control_;
 
   // Node representing the current context within the function body.
   Node* current_context_;
 
   // Merge of all control nodes that exit the function body.
   Node* exit_control_;
 
   DISALLOW_COPY_AND_ASSIGN(StructuredGraphBuilder);
@@ skipping 43 matching lines @@
 
   // Copies this environment at a loop header control-flow point.
   Environment* CopyForLoop() {
     PrepareForLoop();
     return builder()->CopyEnvironment(this);
   }
 
   Node* GetContext() { return builder_->current_context(); }
 
  protected:
-  // TODO(mstarzinger): Use phase-local zone instead!
-  Zone* zone() const { return graph()->zone(); }
+  Zone* zone() const { return builder_->local_zone(); }
   Graph* graph() const { return builder_->graph(); }
   StructuredGraphBuilder* builder() const { return builder_; }
   CommonOperatorBuilder* common() { return builder_->common(); }
   NodeVector* values() { return &values_; }
 
   // Prepare environment to be used as loop header.
   void PrepareForLoop();
 
  private:
   StructuredGraphBuilder* builder_;
   Node* control_dependency_;
   Node* effect_dependency_;
   NodeVector values_;
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_GRAPH_BUILDER_H__