Optimizing nested, constant object literals (like JSON objects) by building o...

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 111 matching lines @@
   virtual VariableProxy* AsVariableProxy() { return NULL; }
   virtual Property* AsProperty() { return NULL; }
   virtual Call* AsCall() { return NULL; }
   virtual TargetCollector* AsTargetCollector() { return NULL; }
   virtual BreakableStatement* AsBreakableStatement() { return NULL; }
   virtual IterationStatement* AsIterationStatement() { return NULL; }
   virtual UnaryOperation* AsUnaryOperation() { return NULL; }
   virtual BinaryOperation* AsBinaryOperation() { return NULL; }
   virtual Assignment* AsAssignment() { return NULL; }
   virtual FunctionLiteral* AsFunctionLiteral() { return NULL; }
+  virtual ObjectLiteral* AsObjectLiteral() { return NULL; }
 
   void set_statement_pos(int statement_pos) { statement_pos_ = statement_pos; }
   int statement_pos() const { return statement_pos_; }
 
  private:
   int statement_pos_;
 };
 
 
 class Statement: public Node {
@@ skipping 502 matching lines @@
 // for minimizing the work when constructing it at runtime.
 class ObjectLiteral: public MaterializedLiteral {
  public:
   // Property is used for passing information
   // about an object literal's properties from the parser
   // to the code generator.
   class Property: public ZoneObject {
    public:
 
     enum Kind {
-      CONSTANT,       // Property with constant value (at compile time).
-      COMPUTED,       // Property with computed value (at execution time).
+      CONSTANT,        // Property with constant value (at compile time).
+      COMPUTED,        // Property with computed value (at execution time).
+      OBJECT_LITERAL,  // Property value is an object literal.
       GETTER, SETTER,  // Property is an accessor function.
-      PROTOTYPE       // Property is __proto__.
+      PROTOTYPE        // Property is __proto__.
     };
 
     Property(Literal* key, Expression* value);
     Property(bool is_getter, FunctionLiteral* value);
 
     Literal* key() { return key_; }
     Expression* value() { return value_; }
     Kind kind() { return kind_; }
 
    private:
     Literal* key_;
     Expression* value_;
     Kind kind_;
   };
 
   ObjectLiteral(Handle<FixedArray> constant_properties,
                 ZoneList<Property*>* properties,
-                int literal_index)
+                int literal_index,
+                bool is_simple)
       : MaterializedLiteral(literal_index),
         constant_properties_(constant_properties),
-        properties_(properties) {
+        properties_(properties),
+        is_simple_(is_simple) {
   }
 
+  virtual ObjectLiteral* AsObjectLiteral() { return this; }
   virtual void Accept(AstVisitor* v);
 
   Handle<FixedArray> constant_properties() const {
     return constant_properties_;
   }
   ZoneList<Property*>* properties() const { return properties_; }
 
+  // An object literal is simple if the values consist of only
+  // constants and simple object literals.
+  bool is_simple() const { return is_simple_; }
+
  private:
   Handle<FixedArray> constant_properties_;
   ZoneList<Property*>* properties_;
+  bool is_simple_;
 };
 
 
 // Node for capturing a regexp literal.
 class RegExpLiteral: public MaterializedLiteral {
  public:
   RegExpLiteral(Handle<String> pattern,
                 Handle<String> flags,
                 int literal_index)
       : MaterializedLiteral(literal_index),
@@ skipping 943 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_