Initialize reaching definitions state for all flow graph nodes.

src/ast.h

 // Copyright 2010 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 186 matching lines @@
 
   Expression()
       : bitfields_(0),
         def_(NULL),
         defined_vars_(NULL) {}
 
   virtual Expression* AsExpression()  { return this; }
 
   virtual bool IsValidLeftHandSide() { return false; }
 
+  virtual Variable* AssignedVar() { return NULL; }
+
   // Symbols that cannot be parsed as array indices are considered property
   // names.  We do not treat symbols that can be array indexes as property
   // names because [] for string objects is handled only by keyed ICs.
   virtual bool IsPropertyName() { return false; }
 
   // True if the expression does not have (evaluated) subexpressions.
   // Function literals are leaves because their subexpressions are not
   // evaluated.
   virtual bool IsLeaf() { return false; }
 
@@ skipping 1054 matching lines @@
  public:
   CountOperation(bool is_prefix, Token::Value op, Expression* expression)
       : is_prefix_(is_prefix), op_(op), expression_(expression) {
     ASSERT(Token::IsCountOp(op));
   }
 
   virtual void Accept(AstVisitor* v);
 
   virtual CountOperation* AsCountOperation() { return this; }
 
+  virtual Variable* AssignedVar() {
+    return expression()->AsVariableProxy()->AsVariable();
+  }
+
   bool is_prefix() const { return is_prefix_; }
   bool is_postfix() const { return !is_prefix_; }
   Token::Value op() const { return op_; }
   Token::Value binary_op() {
     return op_ == Token::INC ? Token::ADD : Token::SUB;
   }
   Expression* expression() const { return expression_; }
 
   virtual void MarkAsStatement() { is_prefix_ = true; }
 
@@ skipping 60 matching lines @@
       : op_(op), target_(target), value_(value), pos_(pos),
         block_start_(false), block_end_(false) {
     ASSERT(Token::IsAssignmentOp(op));
   }
 
   virtual void Accept(AstVisitor* v);
   virtual Assignment* AsAssignment() { return this; }
 
   Assignment* AsSimpleAssignment() { return !is_compound() ? this : NULL; }
 
+  virtual Variable* AssignedVar() {
+    return target()->AsVariableProxy()->AsVariable();
+  }
+
   Token::Value binary_op() const;
 
   Token::Value op() const { return op_; }
   Expression* target() const { return target_; }
   Expression* value() const { return value_; }
   int position() { return pos_; }
   // This check relies on the definition order of token in token.h.
   bool is_compound() const { return op() > Token::ASSIGN; }
 
   // An initialization block is a series of statments of the form
@@ skipping 539 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_