Use a local variable to save/restore the context on entry/exit, instead of

runtime/vm/parser.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "vm/ast.h"
@@ skipping 17 matching lines @@
 struct FieldInitExpression;
 
 // The class ParsedFunction holds the result of parsing a function.
 class ParsedFunction : ValueObject {
  public:
   explicit ParsedFunction(const Function& function)
       : function_(function),
         node_sequence_(NULL),
         instantiator_(NULL),
         default_parameter_values_(Array::Handle()),
+        saved_context_var_(NULL),
         first_parameter_index_(0),
         first_stack_local_index_(0),
         copied_parameter_count_(0),
         stack_local_count_(0) { }
 
   const Function& function() const { return function_; }
 
   SequenceNode* node_sequence() const { return node_sequence_; }
   void set_node_sequence(SequenceNode* node_sequence) {
     ASSERT(node_sequence != NULL);
     node_sequence_ = node_sequence;
   }
 
   AstNode* instantiator() const { return instantiator_; }
   void set_instantiator(AstNode* instantiator) {
     // May be NULL.
     instantiator_ = instantiator;
   }
 
   const Array& default_parameter_values() const {
     return default_parameter_values_;
   }
   void set_default_parameter_values(const Array& default_parameter_values) {
     default_parameter_values_ = default_parameter_values.raw();
   }
 
+  LocalVariable* saved_context_var() const { return saved_context_var_; }
+  void set_saved_context_var(LocalVariable* saved_context_var) {
+    ASSERT(saved_context_var != NULL);
+    saved_context_var_ = saved_context_var;
+  }
+
   int first_parameter_index() const { return first_parameter_index_; }
   int first_stack_local_index() const { return first_stack_local_index_; }
   int copied_parameter_count() const { return copied_parameter_count_; }
   int stack_local_count() const { return stack_local_count_; }
 
   void AllocateVariables();
 
  private:
   const Function& function_;
   SequenceNode* node_sequence_;
   AstNode* instantiator_;
   Array& default_parameter_values_;
+  LocalVariable* saved_context_var_;
 
   int first_parameter_index_;
   int first_stack_local_index_;
   int copied_parameter_count_;
   int stack_local_count_;
 
   DISALLOW_COPY_AND_ASSIGN(ParsedFunction);
 };
 
 
@@ skipping 410 matching lines @@
   // code at all points in the try block where an exit from the block is
   // done using 'return', 'break' or 'continue' statements.
   TryBlocks* try_blocks_list_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_