X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/9dae56ea45a0f5f8136a5c93d6f3a7f99399ca73..1df5f87f1309a8daa30dabdee855f48ae40d14ab:/runtime/JSObject.cpp?ds=sidebyside

diff --git a/runtime/JSObject.cpp b/runtime/JSObject.cpp
index e9e95f6..dbf9ccf 100644
--- a/runtime/JSObject.cpp
+++ b/runtime/JSObject.cpp
@@ -1,7 +1,7 @@
 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
- *  Copyright (C) 2003, 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
+ *  Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Apple Inc. All rights reserved.
  *  Copyright (C) 2007 Eric Seidel (eric@webkit.org)
  *
  *  This library is free software; you can redistribute it and/or
@@ -27,9 +27,11 @@
 #include "DatePrototype.h"
 #include "ErrorConstructor.h"
 #include "GetterSetter.h"
+#include "JSFunction.h"
 #include "JSGlobalObject.h"
 #include "NativeErrorConstructor.h"
 #include "ObjectPrototype.h"
+#include "PropertyDescriptor.h"
 #include "PropertyNameArray.h"
 #include "Lookup.h"
 #include "Nodes.h"
@@ -37,54 +39,55 @@
 #include <math.h>
 #include <wtf/Assertions.h>
 
-#define JSOBJECT_MARK_TRACING 0
-
-#if JSOBJECT_MARK_TRACING
-
-#define JSOBJECT_MARK_BEGIN() \
-    static int markStackDepth = 0; \
-    for (int i = 0; i < markStackDepth; i++) \
-        putchar('-'); \
-    printf("%s (%p)\n", className().UTF8String().c_str(), this); \
-    markStackDepth++; \
-
-#define JSOBJECT_MARK_END() \
-    markStackDepth--;
+namespace JSC {
 
-#else // JSOBJECT_MARK_TRACING
+ASSERT_CLASS_FITS_IN_CELL(JSObject);
+ASSERT_CLASS_FITS_IN_CELL(JSNonFinalObject);
+ASSERT_CLASS_FITS_IN_CELL(JSFinalObject);
 
-#define JSOBJECT_MARK_BEGIN()
-#define JSOBJECT_MARK_END()
+const char* StrictModeReadonlyPropertyWriteError = "Attempted to assign to readonly property.";
 
-#endif // JSOBJECT_MARK_TRACING
+const ClassInfo JSObject::s_info = { "Object", 0, 0, 0 };
 
-namespace JSC {
+static inline void getClassPropertyNames(ExecState* exec, const ClassInfo* classInfo, PropertyNameArray& propertyNames, EnumerationMode mode)
+{
+    // Add properties from the static hashtables of properties
+    for (; classInfo; classInfo = classInfo->parentClass) {
+        const HashTable* table = classInfo->propHashTable(exec);
+        if (!table)
+            continue;
+        table->initializeIfNeeded(exec);
+        ASSERT(table->table);
 
-ASSERT_CLASS_FITS_IN_CELL(JSObject);
+        int hashSizeMask = table->compactSize - 1;
+        const HashEntry* entry = table->table;
+        for (int i = 0; i <= hashSizeMask; ++i, ++entry) {
+            if (entry->key() && (!(entry->attributes() & DontEnum) || (mode == IncludeDontEnumProperties)))
+                propertyNames.add(entry->key());
+        }
+    }
+}
 
-void JSObject::mark()
+void JSObject::visitChildren(SlotVisitor& visitor)
 {
-    JSOBJECT_MARK_BEGIN();
-
-    JSCell::mark();
-    m_structure->mark();
+    ASSERT_GC_OBJECT_INHERITS(this, &s_info);
+#ifndef NDEBUG
+    bool wasCheckingForDefaultMarkViolation = visitor.m_isCheckingForDefaultMarkViolation;
+    visitor.m_isCheckingForDefaultMarkViolation = false;
+#endif
 
-    size_t storageSize = m_structure->propertyStorageSize();
-    for (size_t i = 0; i < storageSize; ++i) {
-        JSValuePtr v = m_propertyStorage[i];
-        if (!v.marked())
-            v.mark();
-    }
+    visitChildrenDirect(visitor);
 
-    JSOBJECT_MARK_END();
+#ifndef NDEBUG
+    visitor.m_isCheckingForDefaultMarkViolation = wasCheckingForDefaultMarkViolation;
+#endif
 }
 
 UString JSObject::className() const
 {
     const ClassInfo* info = classInfo();
-    if (info)
-        return info->className;
-    return "Object";
+    ASSERT(info);
+    return info->className;
 }
 
 bool JSObject::getOwnPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
@@ -94,11 +97,11 @@ bool JSObject::getOwnPropertySlot(ExecState* exec, unsigned propertyName, Proper
 
 static void throwSetterError(ExecState* exec)
 {
-    throwError(exec, TypeError, "setting a property that has only a getter");
+    throwError(exec, createTypeError(exec, "setting a property that has only a getter"));
 }
 
 // ECMA 8.6.2.2
-void JSObject::put(ExecState* exec, const Identifier& propertyName, JSValuePtr value, PutPropertySlot& slot)
+void JSObject::put(ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
 {
     ASSERT(value);
     ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
@@ -107,37 +110,32 @@ void JSObject::put(ExecState* exec, const Identifier& propertyName, JSValuePtr v
         // Setting __proto__ to a non-object, non-null value is silently ignored to match Mozilla.
         if (!value.isObject() && !value.isNull())
             return;
-
-        JSValuePtr nextPrototypeValue = value;
-        while (nextPrototypeValue && nextPrototypeValue.isObject()) {
-            JSObject* nextPrototype = asObject(nextPrototypeValue)->unwrappedObject();
-            if (nextPrototype == this) {
-                throwError(exec, GeneralError, "cyclic __proto__ value");
-                return;
-            }
-            nextPrototypeValue = nextPrototype->prototype();
-        }
-
-        setPrototype(value);
+        if (!setPrototypeWithCycleCheck(exec->globalData(), value))
+            throwError(exec, createError(exec, "cyclic __proto__ value"));
         return;
     }
 
     // Check if there are any setters or getters in the prototype chain
-    JSValuePtr prototype;
+    JSValue prototype;
     for (JSObject* obj = this; !obj->structure()->hasGetterSetterProperties(); obj = asObject(prototype)) {
         prototype = obj->prototype();
         if (prototype.isNull()) {
-            putDirect(propertyName, value, 0, true, slot);
+            if (!putDirectInternal(exec->globalData(), propertyName, value, 0, true, slot) && slot.isStrictMode())
+                throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
             return;
         }
     }
     
     unsigned attributes;
-    if ((m_structure->get(propertyName, attributes) != WTF::notFound) && attributes & ReadOnly)
+    JSCell* specificValue;
+    if ((m_structure->get(exec->globalData(), propertyName, attributes, specificValue) != WTF::notFound) && attributes & ReadOnly) {
+        if (slot.isStrictMode())
+            throwError(exec, createTypeError(exec, StrictModeReadonlyPropertyWriteError));
         return;
+    }
 
     for (JSObject* obj = this; ; obj = asObject(prototype)) {
-        if (JSValuePtr gs = obj->getDirect(propertyName)) {
+        if (JSValue gs = obj->getDirect(exec->globalData(), propertyName)) {
             if (gs.isGetterSetter()) {
                 JSObject* setterFunc = asGetterSetter(gs)->setter();        
                 if (!setterFunc) {
@@ -147,7 +145,7 @@ void JSObject::put(ExecState* exec, const Identifier& propertyName, JSValuePtr v
                 
                 CallData callData;
                 CallType callType = setterFunc->getCallData(callData);
-                ArgList args;
+                MarkedArgumentBuffer args;
                 args.append(value);
                 call(exec, setterFunc, callType, callData, this, args);
                 return;
@@ -163,22 +161,43 @@ void JSObject::put(ExecState* exec, const Identifier& propertyName, JSValuePtr v
             break;
     }
 
-    putDirect(propertyName, value, 0, true, slot);
+    if (!putDirectInternal(exec->globalData(), propertyName, value, 0, true, slot) && slot.isStrictMode())
+        throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
     return;
 }
 
-void JSObject::put(ExecState* exec, unsigned propertyName, JSValuePtr value)
+void JSObject::put(ExecState* exec, unsigned propertyName, JSValue value)
 {
     PutPropertySlot slot;
     put(exec, Identifier::from(exec, propertyName), value, slot);
 }
 
-void JSObject::putWithAttributes(ExecState*, const Identifier& propertyName, JSValuePtr value, unsigned attributes)
+void JSObject::putWithAttributes(JSGlobalData* globalData, const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot)
+{
+    putDirectInternal(*globalData, propertyName, value, attributes, checkReadOnly, slot);
+}
+
+void JSObject::putWithAttributes(JSGlobalData* globalData, const Identifier& propertyName, JSValue value, unsigned attributes)
+{
+    putDirectInternal(*globalData, propertyName, value, attributes);
+}
+
+void JSObject::putWithAttributes(JSGlobalData* globalData, unsigned propertyName, JSValue value, unsigned attributes)
+{
+    putWithAttributes(globalData, Identifier::from(globalData, propertyName), value, attributes);
+}
+
+void JSObject::putWithAttributes(ExecState* exec, const Identifier& propertyName, JSValue value, unsigned attributes, bool checkReadOnly, PutPropertySlot& slot)
+{
+    putDirectInternal(exec->globalData(), propertyName, value, attributes, checkReadOnly, slot);
+}
+
+void JSObject::putWithAttributes(ExecState* exec, const Identifier& propertyName, JSValue value, unsigned attributes)
 {
-    putDirect(propertyName, value, attributes);
+    putDirectInternal(exec->globalData(), propertyName, value, attributes);
 }
 
-void JSObject::putWithAttributes(ExecState* exec, unsigned propertyName, JSValuePtr value, unsigned attributes)
+void JSObject::putWithAttributes(ExecState* exec, unsigned propertyName, JSValue value, unsigned attributes)
 {
     putWithAttributes(exec, Identifier::from(exec, propertyName), value, attributes);
 }
@@ -199,10 +218,11 @@ bool JSObject::hasProperty(ExecState* exec, unsigned propertyName) const
 bool JSObject::deleteProperty(ExecState* exec, const Identifier& propertyName)
 {
     unsigned attributes;
-    if (m_structure->get(propertyName, attributes) != WTF::notFound) {
+    JSCell* specificValue;
+    if (m_structure->get(exec->globalData(), propertyName, attributes, specificValue) != WTF::notFound) {
         if ((attributes & DontDelete))
             return false;
-        removeDirect(propertyName);
+        removeDirect(exec->globalData(), propertyName);
         return true;
     }
 
@@ -226,11 +246,11 @@ bool JSObject::deleteProperty(ExecState* exec, unsigned propertyName)
     return deleteProperty(exec, Identifier::from(exec, propertyName));
 }
 
-static ALWAYS_INLINE JSValuePtr callDefaultValueFunction(ExecState* exec, const JSObject* object, const Identifier& propertyName)
+static ALWAYS_INLINE JSValue callDefaultValueFunction(ExecState* exec, const JSObject* object, const Identifier& propertyName)
 {
-    JSValuePtr function = object->get(exec, propertyName);
+    JSValue function = object->get(exec, propertyName);
     CallData callData;
-    CallType callType = function.getCallData(callData);
+    CallType callType = getCallData(function, callData);
     if (callType == CallTypeNone)
         return exec->exception();
 
@@ -239,16 +259,16 @@ static ALWAYS_INLINE JSValuePtr callDefaultValueFunction(ExecState* exec, const
     if (exec->hadException())
         return exec->exception();
 
-    JSValuePtr result = call(exec, function, callType, callData, const_cast<JSObject*>(object), exec->emptyList());
+    JSValue result = call(exec, function, callType, callData, const_cast<JSObject*>(object), exec->emptyList());
     ASSERT(!result.isGetterSetter());
     if (exec->hadException())
         return exec->exception();
     if (result.isObject())
-        return noValue();
+        return JSValue();
     return result;
 }
 
-bool JSObject::getPrimitiveNumber(ExecState* exec, double& number, JSValuePtr& result)
+bool JSObject::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result)
 {
     result = defaultValue(exec, PreferNumber);
     number = result.toNumber(exec);
@@ -256,18 +276,18 @@ bool JSObject::getPrimitiveNumber(ExecState* exec, double& number, JSValuePtr& r
 }
 
 // ECMA 8.6.2.6
-JSValuePtr JSObject::defaultValue(ExecState* exec, PreferredPrimitiveType hint) const
+JSValue JSObject::defaultValue(ExecState* exec, PreferredPrimitiveType hint) const
 {
     // Must call toString first for Date objects.
     if ((hint == PreferString) || (hint != PreferNumber && prototype() == exec->lexicalGlobalObject()->datePrototype())) {
-        JSValuePtr value = callDefaultValueFunction(exec, this, exec->propertyNames().toString);
+        JSValue value = callDefaultValueFunction(exec, this, exec->propertyNames().toString);
         if (value)
             return value;
         value = callDefaultValueFunction(exec, this, exec->propertyNames().valueOf);
         if (value)
             return value;
     } else {
-        JSValuePtr value = callDefaultValueFunction(exec, this, exec->propertyNames().valueOf);
+        JSValue value = callDefaultValueFunction(exec, this, exec->propertyNames().valueOf);
         if (value)
             return value;
         value = callDefaultValueFunction(exec, this, exec->propertyNames().toString);
@@ -277,7 +297,7 @@ JSValuePtr JSObject::defaultValue(ExecState* exec, PreferredPrimitiveType hint)
 
     ASSERT(!exec->hadException());
 
-    return throwError(exec, TypeError, "No default value");
+    return throwError(exec, createTypeError(exec, "No default value"));
 }
 
 const HashEntry* JSObject::findPropertyHashEntry(ExecState* exec, const Identifier& propertyName) const
@@ -291,65 +311,72 @@ const HashEntry* JSObject::findPropertyHashEntry(ExecState* exec, const Identifi
     return 0;
 }
 
-void JSObject::defineGetter(ExecState* exec, const Identifier& propertyName, JSObject* getterFunction)
+void JSObject::defineGetter(ExecState* exec, const Identifier& propertyName, JSObject* getterFunction, unsigned attributes)
 {
-    JSValuePtr object = getDirect(propertyName);
+    if (propertyName == exec->propertyNames().underscoreProto) {
+        // Defining a getter for __proto__ is silently ignored.
+        return;
+    }
+
+    JSValue object = getDirect(exec->globalData(), propertyName);
     if (object && object.isGetterSetter()) {
         ASSERT(m_structure->hasGetterSetterProperties());
-        asGetterSetter(object)->setGetter(getterFunction);
+        asGetterSetter(object)->setGetter(exec->globalData(), getterFunction);
         return;
     }
 
+    JSGlobalData& globalData = exec->globalData();
     PutPropertySlot slot;
-    GetterSetter* getterSetter = new (exec) GetterSetter;
-    putDirect(propertyName, getterSetter, None, true, slot);
+    GetterSetter* getterSetter = new (exec) GetterSetter(exec);
+    putDirectInternal(globalData, propertyName, getterSetter, attributes | Getter, true, slot);
 
     // putDirect will change our Structure if we add a new property. For
     // getters and setters, though, we also need to change our Structure
     // if we override an existing non-getter or non-setter.
     if (slot.type() != PutPropertySlot::NewProperty) {
-        if (!m_structure->isDictionary()) {
-            RefPtr<Structure> structure = Structure::getterSetterTransition(m_structure);
-            setStructure(structure.release());
-        }
+        if (!m_structure->isDictionary())
+            setStructure(exec->globalData(), Structure::getterSetterTransition(globalData, m_structure.get()));
     }
 
     m_structure->setHasGetterSetterProperties(true);
-    getterSetter->setGetter(getterFunction);
+    getterSetter->setGetter(globalData, getterFunction);
 }
 
-void JSObject::defineSetter(ExecState* exec, const Identifier& propertyName, JSObject* setterFunction)
+void JSObject::defineSetter(ExecState* exec, const Identifier& propertyName, JSObject* setterFunction, unsigned attributes)
 {
-    JSValuePtr object = getDirect(propertyName);
+    if (propertyName == exec->propertyNames().underscoreProto) {
+        // Defining a setter for __proto__ is silently ignored.
+        return;
+    }
+
+    JSValue object = getDirect(exec->globalData(), propertyName);
     if (object && object.isGetterSetter()) {
         ASSERT(m_structure->hasGetterSetterProperties());
-        asGetterSetter(object)->setSetter(setterFunction);
+        asGetterSetter(object)->setSetter(exec->globalData(), setterFunction);
         return;
     }
 
     PutPropertySlot slot;
-    GetterSetter* getterSetter = new (exec) GetterSetter;
-    putDirect(propertyName, getterSetter, None, true, slot);
+    GetterSetter* getterSetter = new (exec) GetterSetter(exec);
+    putDirectInternal(exec->globalData(), propertyName, getterSetter, attributes | Setter, true, slot);
 
     // putDirect will change our Structure if we add a new property. For
     // getters and setters, though, we also need to change our Structure
     // if we override an existing non-getter or non-setter.
     if (slot.type() != PutPropertySlot::NewProperty) {
-        if (!m_structure->isDictionary()) {
-            RefPtr<Structure> structure = Structure::getterSetterTransition(m_structure);
-            setStructure(structure.release());
-        }
+        if (!m_structure->isDictionary())
+            setStructure(exec->globalData(), Structure::getterSetterTransition(exec->globalData(), m_structure.get()));
     }
 
     m_structure->setHasGetterSetterProperties(true);
-    getterSetter->setSetter(setterFunction);
+    getterSetter->setSetter(exec->globalData(), setterFunction);
 }
 
-JSValuePtr JSObject::lookupGetter(ExecState*, const Identifier& propertyName)
+JSValue JSObject::lookupGetter(ExecState* exec, const Identifier& propertyName)
 {
     JSObject* object = this;
     while (true) {
-        if (JSValuePtr value = object->getDirect(propertyName)) {
+        if (JSValue value = object->getDirect(exec->globalData(), propertyName)) {
             if (!value.isGetterSetter())
                 return jsUndefined();
             JSObject* functionObject = asGetterSetter(value)->getter();
@@ -364,11 +391,11 @@ JSValuePtr JSObject::lookupGetter(ExecState*, const Identifier& propertyName)
     }
 }
 
-JSValuePtr JSObject::lookupSetter(ExecState*, const Identifier& propertyName)
+JSValue JSObject::lookupSetter(ExecState* exec, const Identifier& propertyName)
 {
     JSObject* object = this;
     while (true) {
-        if (JSValuePtr value = object->getDirect(propertyName)) {
+        if (JSValue value = object->getDirect(exec->globalData(), propertyName)) {
             if (!value.isGetterSetter())
                 return jsUndefined();
             JSObject* functionObject = asGetterSetter(value)->setter();
@@ -383,15 +410,15 @@ JSValuePtr JSObject::lookupSetter(ExecState*, const Identifier& propertyName)
     }
 }
 
-bool JSObject::hasInstance(ExecState* exec, JSValuePtr value, JSValuePtr proto)
+bool JSObject::hasInstance(ExecState* exec, JSValue value, JSValue proto)
 {
-    if (!proto.isObject()) {
-        throwError(exec, TypeError, "instanceof called on an object with an invalid prototype property.");
+    if (!value.isObject())
         return false;
-    }
 
-    if (!value.isObject())
+    if (!proto.isObject()) {
+        throwError(exec, createTypeError(exec, "instanceof called on an object with an invalid prototype property."));
         return false;
+    }
 
     JSObject* object = asObject(value);
     while ((object = object->prototype().getObject())) {
@@ -403,30 +430,50 @@ bool JSObject::hasInstance(ExecState* exec, JSValuePtr value, JSValuePtr proto)
 
 bool JSObject::propertyIsEnumerable(ExecState* exec, const Identifier& propertyName) const
 {
-    unsigned attributes;
-    if (!getPropertyAttributes(exec, propertyName, attributes))
+    PropertyDescriptor descriptor;
+    if (!const_cast<JSObject*>(this)->getOwnPropertyDescriptor(exec, propertyName, descriptor))
         return false;
-    return !(attributes & DontEnum);
+    return descriptor.enumerable();
 }
 
-bool JSObject::getPropertyAttributes(ExecState* exec, const Identifier& propertyName, unsigned& attributes) const
+bool JSObject::getPropertySpecificValue(ExecState* exec, const Identifier& propertyName, JSCell*& specificValue) const
 {
-    if (m_structure->get(propertyName, attributes) != WTF::notFound)
-        return true;
-    
-    // Look in the static hashtable of properties
-    const HashEntry* entry = findPropertyHashEntry(exec, propertyName);
-    if (entry) {
-        attributes = entry->attributes();
+    unsigned attributes;
+    if (m_structure->get(exec->globalData(), propertyName, attributes, specificValue) != WTF::notFound)
         return true;
-    }
-    
+
+    // This could be a function within the static table? - should probably
+    // also look in the hash?  This currently should not be a problem, since
+    // we've currently always call 'get' first, which should have populated
+    // the normal storage.
     return false;
 }
 
-void JSObject::getPropertyNames(ExecState* exec, PropertyNameArray& propertyNames)
+void JSObject::getPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
+{
+    getOwnPropertyNames(exec, propertyNames, mode);
+
+    if (prototype().isNull())
+        return;
+
+    JSObject* prototype = asObject(this->prototype());
+    while(1) {
+        if (prototype->structure()->typeInfo().overridesGetPropertyNames()) {
+            prototype->getPropertyNames(exec, propertyNames, mode);
+            break;
+        }
+        prototype->getOwnPropertyNames(exec, propertyNames, mode);
+        JSValue nextProto = prototype->prototype();
+        if (nextProto.isNull())
+            break;
+        prototype = asObject(nextProto);
+    }
+}
+
+void JSObject::getOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 {
-    m_structure->getEnumerablePropertyNames(exec, propertyNames, this);
+    m_structure->getPropertyNames(exec->globalData(), propertyNames, mode);
+    getClassPropertyNames(exec, classInfo(), propertyNames, mode);
 }
 
 bool JSObject::toBoolean(ExecState*) const
@@ -436,7 +483,7 @@ bool JSObject::toBoolean(ExecState*) const
 
 double JSObject::toNumber(ExecState* exec) const
 {
-    JSValuePtr primitive = toPrimitive(exec, PreferNumber);
+    JSValue primitive = toPrimitive(exec, PreferNumber);
     if (exec->hadException()) // should be picked up soon in Nodes.cpp
         return 0.0;
     return primitive.toNumber(exec);
@@ -444,13 +491,13 @@ double JSObject::toNumber(ExecState* exec) const
 
 UString JSObject::toString(ExecState* exec) const
 {
-    JSValuePtr primitive = toPrimitive(exec, PreferString);
+    JSValue primitive = toPrimitive(exec, PreferString);
     if (exec->hadException())
         return "";
     return primitive.toString(exec);
 }
 
-JSObject* JSObject::toObject(ExecState*) const
+JSObject* JSObject::toObject(ExecState*, JSGlobalObject*) const
 {
     return const_cast<JSObject*>(this);
 }
@@ -460,59 +507,294 @@ JSObject* JSObject::toThisObject(ExecState*) const
     return const_cast<JSObject*>(this);
 }
 
+JSValue JSObject::toStrictThisObject(ExecState*) const
+{
+    return const_cast<JSObject*>(this);
+}
+
 JSObject* JSObject::unwrappedObject()
 {
     return this;
 }
 
-void JSObject::removeDirect(const Identifier& propertyName)
+void JSObject::seal(JSGlobalData& globalData)
 {
+    if (isSealed(globalData))
+        return;
+    preventExtensions(globalData);
+    setStructure(globalData, Structure::sealTransition(globalData, m_structure.get()));
+}
+
+void JSObject::freeze(JSGlobalData& globalData)
+{
+    if (isFrozen(globalData))
+        return;
+    preventExtensions(globalData);
+    setStructure(globalData, Structure::freezeTransition(globalData, m_structure.get()));
+}
+
+void JSObject::preventExtensions(JSGlobalData& globalData)
+{
+    if (isExtensible())
+        setStructure(globalData, Structure::preventExtensionsTransition(globalData, m_structure.get()));
+}
+
+void JSObject::removeDirect(JSGlobalData& globalData, const Identifier& propertyName)
+{
+    if (m_structure->get(globalData, propertyName) == WTF::notFound)
+        return;
+
     size_t offset;
-    if (m_structure->isDictionary()) {
-        offset = m_structure->removePropertyWithoutTransition(propertyName);
+    if (m_structure->isUncacheableDictionary()) {
+        offset = m_structure->removePropertyWithoutTransition(globalData, propertyName);
         if (offset != WTF::notFound)
-            m_propertyStorage[offset] = jsUndefined();
+            putUndefinedAtDirectOffset(offset);
         return;
     }
 
-    RefPtr<Structure> structure = Structure::removePropertyTransition(m_structure, propertyName, offset);
+    setStructure(globalData, Structure::removePropertyTransition(globalData, m_structure.get(), propertyName, offset));
     if (offset != WTF::notFound)
-        m_propertyStorage[offset] = jsUndefined();
-    setStructure(structure.release());
+        putUndefinedAtDirectOffset(offset);
 }
 
 void JSObject::putDirectFunction(ExecState* exec, InternalFunction* function, unsigned attr)
 {
-    putDirect(Identifier(exec, function->name(&exec->globalData())), function, attr);
+    putDirectFunction(exec->globalData(), Identifier(exec, function->name(exec)), function, attr);
+}
+
+void JSObject::putDirectFunction(ExecState* exec, JSFunction* function, unsigned attr)
+{
+    putDirectFunction(exec->globalData(), Identifier(exec, function->name(exec)), function, attr);
 }
 
 void JSObject::putDirectFunctionWithoutTransition(ExecState* exec, InternalFunction* function, unsigned attr)
 {
-    putDirectWithoutTransition(Identifier(exec, function->name(&exec->globalData())), function, attr);
+    putDirectFunctionWithoutTransition(exec->globalData(), Identifier(exec, function->name(exec)), function, attr);
 }
 
-NEVER_INLINE void JSObject::fillGetterPropertySlot(PropertySlot& slot, JSValuePtr* location)
+void JSObject::putDirectFunctionWithoutTransition(ExecState* exec, JSFunction* function, unsigned attr)
 {
-    if (JSObject* getterFunction = asGetterSetter(*location)->getter())
-        slot.setGetterSlot(getterFunction);
-    else
+    putDirectFunctionWithoutTransition(exec->globalData(), Identifier(exec, function->name(exec)), function, attr);
+}
+
+NEVER_INLINE void JSObject::fillGetterPropertySlot(PropertySlot& slot, WriteBarrierBase<Unknown>* location)
+{
+    if (JSObject* getterFunction = asGetterSetter(location->get())->getter()) {
+        if (!structure()->isDictionary())
+            slot.setCacheableGetterSlot(this, getterFunction, offsetForLocation(location));
+        else
+            slot.setGetterSlot(getterFunction);
+    } else
         slot.setUndefined();
 }
 
-Structure* JSObject::createInheritorID()
+Structure* JSObject::createInheritorID(JSGlobalData& globalData)
 {
-    m_inheritorID = JSObject::createStructure(this);
+    m_inheritorID.set(globalData, this, createEmptyObjectStructure(globalData, this));
+    ASSERT(m_inheritorID->isEmpty());
     return m_inheritorID.get();
 }
 
 void JSObject::allocatePropertyStorage(size_t oldSize, size_t newSize)
 {
-    allocatePropertyStorageInline(oldSize, newSize);
+    ASSERT(newSize > oldSize);
+
+    // It's important that this function not rely on m_structure, since
+    // we might be in the middle of a transition.
+    bool wasInline = (oldSize < JSObject::baseExternalStorageCapacity);
+
+    PropertyStorage oldPropertyStorage = m_propertyStorage;
+    PropertyStorage newPropertyStorage = new WriteBarrierBase<Unknown>[newSize];
+
+    for (unsigned i = 0; i < oldSize; ++i)
+       newPropertyStorage[i] = oldPropertyStorage[i];
+
+    if (!wasInline)
+        delete [] oldPropertyStorage;
+
+    m_propertyStorage = newPropertyStorage;
+}
+
+bool JSObject::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
+{
+    unsigned attributes = 0;
+    JSCell* cell = 0;
+    size_t offset = m_structure->get(exec->globalData(), propertyName, attributes, cell);
+    if (offset == WTF::notFound)
+        return false;
+    descriptor.setDescriptor(getDirectOffset(offset), attributes);
+    return true;
+}
+
+bool JSObject::getPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
+{
+    JSObject* object = this;
+    while (true) {
+        if (object->getOwnPropertyDescriptor(exec, propertyName, descriptor))
+            return true;
+        JSValue prototype = object->prototype();
+        if (!prototype.isObject())
+            return false;
+        object = asObject(prototype);
+    }
+}
+
+static bool putDescriptor(ExecState* exec, JSObject* target, const Identifier& propertyName, PropertyDescriptor& descriptor, unsigned attributes, const PropertyDescriptor& oldDescriptor)
+{
+    if (descriptor.isGenericDescriptor() || descriptor.isDataDescriptor()) {
+        if (descriptor.isGenericDescriptor() && oldDescriptor.isAccessorDescriptor()) {
+            GetterSetter* accessor = new (exec) GetterSetter(exec);
+            if (oldDescriptor.getter()) {
+                attributes |= Getter;
+                accessor->setGetter(exec->globalData(), asObject(oldDescriptor.getter()));
+            }
+            if (oldDescriptor.setter()) {
+                attributes |= Setter;
+                accessor->setSetter(exec->globalData(), asObject(oldDescriptor.setter()));
+            }
+            target->putWithAttributes(exec, propertyName, accessor, attributes);
+            return true;
+        }
+        JSValue newValue = jsUndefined();
+        if (descriptor.value())
+            newValue = descriptor.value();
+        else if (oldDescriptor.value())
+            newValue = oldDescriptor.value();
+        target->putWithAttributes(exec, propertyName, newValue, attributes & ~(Getter | Setter));
+        return true;
+    }
+    attributes &= ~ReadOnly;
+    if (descriptor.getter() && descriptor.getter().isObject())
+        target->defineGetter(exec, propertyName, asObject(descriptor.getter()), attributes);
+    if (exec->hadException())
+        return false;
+    if (descriptor.setter() && descriptor.setter().isObject())
+        target->defineSetter(exec, propertyName, asObject(descriptor.setter()), attributes);
+    return !exec->hadException();
+}
+
+bool JSObject::defineOwnProperty(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor, bool throwException)
+{
+    // If we have a new property we can just put it on normally
+    PropertyDescriptor current;
+    if (!getOwnPropertyDescriptor(exec, propertyName, current)) {
+        // unless extensions are prevented!
+        if (!isExtensible()) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to define property on object that is not extensible."));
+            return false;
+        }
+        PropertyDescriptor oldDescriptor;
+        oldDescriptor.setValue(jsUndefined());
+        return putDescriptor(exec, this, propertyName, descriptor, descriptor.attributes(), oldDescriptor);
+    }
+
+    if (descriptor.isEmpty())
+        return true;
+
+    if (current.equalTo(exec, descriptor))
+        return true;
+
+    // Filter out invalid changes
+    if (!current.configurable()) {
+        if (descriptor.configurable()) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to configurable attribute of unconfigurable property."));
+            return false;
+        }
+        if (descriptor.enumerablePresent() && descriptor.enumerable() != current.enumerable()) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to change enumerable attribute of unconfigurable property."));
+            return false;
+        }
+    }
+
+    // A generic descriptor is simply changing the attributes of an existing property
+    if (descriptor.isGenericDescriptor()) {
+        if (!current.attributesEqual(descriptor)) {
+            deleteProperty(exec, propertyName);
+            putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current);
+        }
+        return true;
+    }
+
+    // Changing between a normal property or an accessor property
+    if (descriptor.isDataDescriptor() != current.isDataDescriptor()) {
+        if (!current.configurable()) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to change access mechanism for an unconfigurable property."));
+            return false;
+        }
+        deleteProperty(exec, propertyName);
+        return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current);
+    }
+
+    // Changing the value and attributes of an existing property
+    if (descriptor.isDataDescriptor()) {
+        if (!current.configurable()) {
+            if (!current.writable() && descriptor.writable()) {
+                if (throwException)
+                    throwError(exec, createTypeError(exec, "Attempting to change writable attribute of unconfigurable property."));
+                return false;
+            }
+            if (!current.writable()) {
+                if (descriptor.value() || !JSValue::strictEqual(exec, current.value(), descriptor.value())) {
+                    if (throwException)
+                        throwError(exec, createTypeError(exec, "Attempting to change value of a readonly property."));
+                    return false;
+                }
+            }
+        } else if (current.attributesEqual(descriptor)) {
+            if (!descriptor.value())
+                return true;
+            PutPropertySlot slot;
+            put(exec, propertyName, descriptor.value(), slot);
+            if (exec->hadException())
+                return false;
+            return true;
+        }
+        deleteProperty(exec, propertyName);
+        return putDescriptor(exec, this, propertyName, descriptor, current.attributesWithOverride(descriptor), current);
+    }
+
+    // Changing the accessor functions of an existing accessor property
+    ASSERT(descriptor.isAccessorDescriptor());
+    if (!current.configurable()) {
+        if (descriptor.setterPresent() && !(current.setterPresent() && JSValue::strictEqual(exec, current.setter(), descriptor.setter()))) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to change the setter of an unconfigurable property."));
+            return false;
+        }
+        if (descriptor.getterPresent() && !(current.getterPresent() && JSValue::strictEqual(exec, current.getter(), descriptor.getter()))) {
+            if (throwException)
+                throwError(exec, createTypeError(exec, "Attempting to change the getter of an unconfigurable property."));
+            return false;
+        }
+    }
+    JSValue accessor = getDirect(exec->globalData(), propertyName);
+    if (!accessor)
+        return false;
+    GetterSetter* getterSetter = asGetterSetter(accessor);
+    if (current.attributesEqual(descriptor)) {
+        if (descriptor.setter())
+            getterSetter->setSetter(exec->globalData(), asObject(descriptor.setter()));
+        if (descriptor.getter())
+            getterSetter->setGetter(exec->globalData(), asObject(descriptor.getter()));
+        return true;
+    }
+    deleteProperty(exec, propertyName);
+    unsigned attrs = current.attributesWithOverride(descriptor);
+    if (descriptor.setter())
+        attrs |= Setter;
+    if (descriptor.getter())
+        attrs |= Getter;
+    putDirect(exec->globalData(), propertyName, getterSetter, attrs);
+    return true;
 }
 
-JSObject* constructEmptyObject(ExecState* exec)
+JSObject* throwTypeError(ExecState* exec, const UString& message)
 {
-    return new (exec) JSObject(exec->lexicalGlobalObject()->emptyObjectStructure());
+    return throwError(exec, createTypeError(exec, message));
 }
 
 } // namespace JSC