Make Object.freeze fast

src/property-details.h

 // Copyright 2012 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 21 matching lines @@
 #include "allocation.h"
 #include "utils.h"
 
 // Ecma-262 3rd 8.6.1
 enum PropertyAttributes {
   NONE              = v8::None,
   READ_ONLY         = v8::ReadOnly,
   DONT_ENUM         = v8::DontEnum,
   DONT_DELETE       = v8::DontDelete,
 
-  SEALED            = DONT_ENUM | DONT_DELETE,
+  SEALED            = DONT_DELETE,
   FROZEN            = SEALED | READ_ONLY,
 
   SYMBOLIC          = 8,  // Used to filter symbol names
   DONT_SHOW         = DONT_ENUM | SYMBOLIC,
   ABSENT            = 16  // Used in runtime to indicate a property is absent.
   // ABSENT can never be stored in or returned from a descriptor's attributes
   // bitfield.  It is only used as a return value meaning the attributes of
   // a non-existent property.
 };
 
@@ skipping 120 matching lines @@
         | RepresentationField::encode(EncodeRepresentation(representation));
   }
 
   int pointer() { return DescriptorPointer::decode(value_); }
 
   PropertyDetails set_pointer(int i) { return PropertyDetails(value_, i); }
 
   PropertyDetails CopyWithRepresentation(Representation representation) {
     return PropertyDetails(value_, representation);
   }
+  PropertyDetails CopyAddAttributes(PropertyAttributes new_attributes) {
+    new_attributes =
+        static_cast<PropertyAttributes>(attributes() | new_attributes);
+    return PropertyDetails(value_, new_attributes);
+  }
 
   // Conversion for storing details as Object*.
   explicit inline PropertyDetails(Smi* smi);
   inline Smi* AsSmi();
 
   static uint8_t EncodeRepresentation(Representation representation) {
     return representation.kind();
   }
 
   static Representation DecodeRepresentation(uint32_t bits) {
@@ skipping 37 matching lines @@
   static const int kInitialIndex = 1;
 
  private:
   PropertyDetails(int value, int pointer) {
     value_ = DescriptorPointer::update(value, pointer);
   }
   PropertyDetails(int value, Representation representation) {
     value_ = RepresentationField::update(
         value, EncodeRepresentation(representation));
   }
+  PropertyDetails(int value, PropertyAttributes attributes) {
+    value_ = AttributesField::update(value, attributes);
+  }
 
   uint32_t value_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_DETAILS_H_