Change the handling of catch blocks to use context extension objects...

src/ast.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 59 matching lines @@
   V(DebuggerStatement)                          \
   V(FunctionLiteral)                            \
   V(FunctionBoilerplateLiteral)                 \
   V(Conditional)                                \
   V(Slot)                                       \
   V(VariableProxy)                              \
   V(Literal)                                    \
   V(RegExpLiteral)                              \
   V(ObjectLiteral)                              \
   V(ArrayLiteral)                               \
+  V(CatchExtensionObject)                       \
   V(Assignment)                                 \
   V(Throw)                                      \
   V(Property)                                   \
   V(Call)                                       \
   V(CallEval)                                   \
   V(CallNew)                                    \
   V(CallRuntime)                                \
   V(UnaryOperation)                             \
   V(CountOperation)                             \
   V(BinaryOperation)                            \
@@ skipping 625 matching lines @@
 
   Handle<FixedArray> literals() const { return literals_; }
   ZoneList<Expression*>* values() const { return values_; }
 
  private:
   Handle<FixedArray> literals_;
   ZoneList<Expression*>* values_;
 };
 
 
+// Node for constructing a context extension object for a catch block.
+// The catch context extension object has one property, the catch
+// variable, which should be DontDelete.
+class CatchExtensionObject: public Expression {
+ public:
+  CatchExtensionObject(Literal* key, VariableProxy* value)
+      : key_(key), value_(value) {
+  }
+
+  virtual void Accept(AstVisitor* v);
+
+  Literal* key() const { return key_; }
+  VariableProxy* value() const { return value_; }
+
+ private:
+  Literal* key_;
+  VariableProxy* value_;
+};
+
+
 class VariableProxy: public Expression {
  public:
   virtual void Accept(AstVisitor* v);
 
   // Type testing & conversion
   virtual Property* AsProperty() {
     return var_ == NULL ? NULL : var_->AsProperty();
   }
   virtual VariableProxy* AsVariableProxy()  { return this; }
 
@@ skipping 851 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_