JavaScriptCore-1218.35.tar.gz

[apple/javascriptcore.git] / runtime / JSFunction.cpp

diff --git a/runtime/JSFunction.cpp b/runtime/JSFunction.cpp
index cb18115428ab9f6576649705b212b911a21edf29..3b89f6d7ab5777cf1aecf01ef1212a3834fb4310 100644 (file)
--- a/runtime/JSFunction.cpp
+++ b/runtime/JSFunction.cpp
@@ -1,7 +1,7 @@
 /*
  *  Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
 /*
  *  Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)

- *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
+ *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

  *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
  *  Copyright (C) 2007 Maks Orlovich
  *
  *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
  *  Copyright (C) 2007 Maks Orlovich
  *


@@ -28,147 +28,456 @@
 #include "CodeBlock.h"
 #include "CommonIdentifiers.h"
 #include "CallFrame.h"
 #include "CodeBlock.h"
 #include "CommonIdentifiers.h"
 #include "CallFrame.h"

+#include "ExceptionHelpers.h"

 #include "FunctionPrototype.h"
 #include "FunctionPrototype.h"

+#include "GetterSetter.h"
+#include "JSArray.h"

 #include "JSGlobalObject.h"
 #include "JSGlobalObject.h"

+#include "JSNotAnObject.h"

 #include "Interpreter.h"
 #include "Interpreter.h"

+#include "ObjectConstructor.h"

 #include "ObjectPrototype.h"
 #include "ObjectPrototype.h"

+#include "Operations.h"

 #include "Parser.h"
 #include "PropertyNameArray.h"
 #include "Parser.h"
 #include "PropertyNameArray.h"

-#include "ScopeChainMark.h"

 
 using namespace WTF;
 using namespace Unicode;
 
 namespace JSC {
 
 using namespace WTF;
 using namespace Unicode;
 
 namespace JSC {

+EncodedJSValue JSC_HOST_CALL callHostFunctionAsConstructor(ExecState* exec)
+{
+    return throwVMError(exec, createNotAConstructorError(exec, exec->callee()));
+}

 
 

-ASSERT_CLASS_FITS_IN_CELL(JSFunction);
-
-const ClassInfo JSFunction::info = { "Function", &InternalFunction::info, 0, 0 };
+const ClassInfo JSFunction::s_info = { "Function", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(JSFunction) };

 
 

-JSFunction::JSFunction(ExecState* exec, const Identifier& name, FunctionBodyNode* body, ScopeChainNode* scopeChainNode)
-    : Base(&exec->globalData(), exec->lexicalGlobalObject()->functionStructure(), name)
-    , m_body(body)
-    , m_scopeChain(scopeChainNode)
+bool JSFunction::isHostFunctionNonInline() const

 {
 {

+    return isHostFunction();

 }
 
 }
 

-JSFunction::~JSFunction()
+JSFunction* JSFunction::create(ExecState* exec, JSGlobalObject* globalObject, int length, const String& name, NativeFunction nativeFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)

 {
 {

-#if ENABLE(JIT) 
-    // JIT code for other functions may have had calls linked directly to the code for this function; these links
-    // are based on a check for the this pointer value for this JSFunction - which will no longer be valid once
-    // this memory is freed and may be reused (potentially for another, different JSFunction).
-    if (m_body && m_body->isGenerated())
-        m_body->generatedBytecode().unlinkCallers();
+    NativeExecutable* executable;
+#if !ENABLE(JIT)
+    UNUSED_PARAM(intrinsic);
+#else
+    if (intrinsic != NoIntrinsic && exec->vm().canUseJIT()) {
+        ASSERT(nativeConstructor == callHostFunctionAsConstructor);
+        executable = exec->vm().getHostFunction(nativeFunction, intrinsic);
+    } else

 #endif
 #endif

+        executable = exec->vm().getHostFunction(nativeFunction, nativeConstructor);
+
+    JSFunction* function = new (NotNull, allocateCell<JSFunction>(*exec->heap())) JSFunction(exec, globalObject, globalObject->functionStructure());
+    // Can't do this during initialization because getHostFunction might do a GC allocation.
+    function->finishCreation(exec, executable, length, name);
+    return function;
+}
+
+void JSFunction::destroy(JSCell* cell)
+{
+    static_cast<JSFunction*>(cell)->JSFunction::~JSFunction();
+}
+
+JSFunction::JSFunction(ExecState* exec, JSGlobalObject* globalObject, Structure* structure)
+    : Base(exec->vm(), structure)
+    , m_executable()
+    , m_scope(exec->vm(), this, globalObject)
+    // We initialize blind so that changes to the prototype after function creation but before
+    // the optimizer kicks in don't disable optimizations. Once the optimizer kicks in, the
+    // watchpoint will start watching and any changes will both force deoptimization and disable
+    // future attempts to optimize. This is necessary because we are guaranteed that the
+    // allocation profile is changed exactly once prior to optimizations kicking in. We could be
+    // smarter and count the number of times the prototype is clobbered and only optimize if it
+    // was clobbered exactly once, but that seems like overkill. In almost all cases it will be
+    // clobbered once, and if it's clobbered more than once, that will probably only occur
+    // before we started optimizing, anyway.
+    , m_allocationProfileWatchpoint(InitializedBlind)
+{
+}
+
+void JSFunction::finishCreation(ExecState* exec, NativeExecutable* executable, int length, const String& name)
+{
+    Base::finishCreation(exec->vm());
+    ASSERT(inherits(&s_info));
+    m_executable.set(exec->vm(), this, executable);
+    putDirect(exec->vm(), exec->vm().propertyNames->name, jsString(exec, name), DontDelete | ReadOnly | DontEnum);
+    putDirect(exec->vm(), exec->propertyNames().length, jsNumber(length), DontDelete | ReadOnly | DontEnum);
+}
+
+ObjectAllocationProfile* JSFunction::createAllocationProfile(ExecState* exec, size_t inlineCapacity)
+{
+    VM& vm = exec->vm();
+    JSObject* prototype = jsDynamicCast<JSObject*>(get(exec, vm.propertyNames->prototype));
+    if (!prototype)
+        prototype = globalObject()->objectPrototype();
+    m_allocationProfile.initialize(globalObject()->vm(), this, prototype, inlineCapacity);
+    return &m_allocationProfile;
+}
+
+String JSFunction::name(ExecState* exec)
+{
+    return get(exec, exec->vm().propertyNames->name).toWTFString(exec);
+}
+
+String JSFunction::displayName(ExecState* exec)
+{
+    JSValue displayName = getDirect(exec->vm(), exec->vm().propertyNames->displayName);
+    
+    if (displayName && isJSString(displayName))
+        return asString(displayName)->tryGetValue();
+    
+    return String();

 }
 
 }
 

-void JSFunction::mark()
+const String JSFunction::calculatedDisplayName(ExecState* exec)

 {
 {

-    Base::mark();
-    m_body->mark();
-    m_scopeChain.mark();
+    const String explicitName = displayName(exec);
+    
+    if (!explicitName.isEmpty())
+        return explicitName;
+    
+    const String actualName = name(exec);
+    if (!actualName.isEmpty() || isHostFunction())
+        return actualName;
+    
+    return jsExecutable()->inferredName().string();

 }
 
 }
 

-CallType JSFunction::getCallData(CallData& callData)
+const SourceCode* JSFunction::sourceCode() const

 {
 {

-    callData.js.functionBody = m_body.get();
-    callData.js.scopeChain = m_scopeChain.node();
+    if (isHostFunction())
+        return 0;
+    return &jsExecutable()->source();
+}
+
+void JSFunction::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
+    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
+    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
+    Base::visitChildren(thisObject, visitor);
+
+    visitor.append(&thisObject->m_scope);
+    visitor.append(&thisObject->m_executable);
+    thisObject->m_allocationProfile.visitAggregate(visitor);
+}
+
+CallType JSFunction::getCallData(JSCell* cell, CallData& callData)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    if (thisObject->isHostFunction()) {
+        callData.native.function = thisObject->nativeFunction();
+        return CallTypeHost;
+    }
+    callData.js.functionExecutable = thisObject->jsExecutable();
+    callData.js.scope = thisObject->scope();

     return CallTypeJS;
 }
 
     return CallTypeJS;
 }
 

-JSValuePtr JSFunction::call(ExecState* exec, JSValuePtr thisValue, const ArgList& args)
+JSValue JSFunction::argumentsGetter(ExecState* exec, JSValue slotBase, PropertyName)

 {
 {

-    return exec->interpreter()->execute(m_body.get(), exec, this, thisValue.toThisObject(exec), args, m_scopeChain.node(), exec->exceptionSlot());
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObj);

 }
 
 }
 

-JSValuePtr JSFunction::argumentsGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+JSValue JSFunction::callerGetter(ExecState* exec, JSValue slotBase, PropertyName)

 {
 {

-    JSFunction* thisObj = asFunction(slot.slotBase());
-    return exec->interpreter()->retrieveArguments(exec, thisObj);
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    JSValue caller = exec->interpreter()->retrieveCallerFromVMCode(exec, thisObj);
+
+    // See ES5.1 15.3.5.4 - Function.caller may not be used to retrieve a strict caller.
+    if (!caller.isObject() || !asObject(caller)->inherits(&JSFunction::s_info))
+        return caller;
+    JSFunction* function = jsCast<JSFunction*>(caller);
+    if (function->isHostFunction() || !function->jsExecutable()->isStrictMode())
+        return caller;
+    return throwTypeError(exec, ASCIILiteral("Function.caller used to retrieve strict caller"));

 }
 
 }
 

-JSValuePtr JSFunction::callerGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+JSValue JSFunction::lengthGetter(ExecState*, JSValue slotBase, PropertyName)

 {
 {

-    JSFunction* thisObj = asFunction(slot.slotBase());
-    return exec->interpreter()->retrieveCaller(exec, thisObj);
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return jsNumber(thisObj->jsExecutable()->parameterCount());

 }
 
 }
 

-JSValuePtr JSFunction::lengthGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+JSValue JSFunction::nameGetter(ExecState*, JSValue slotBase, PropertyName)

 {
 {

-    JSFunction* thisObj = asFunction(slot.slotBase());
-    return jsNumber(exec, thisObj->m_body->parameterCount());
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return thisObj->jsExecutable()->nameValue();

 }
 
 }
 

-bool JSFunction::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
+bool JSFunction::getOwnPropertySlot(JSCell* cell, ExecState* exec, PropertyName propertyName, PropertySlot& slot)

 {
 {

-    if (propertyName == exec->propertyNames().prototype) {
-        JSValuePtr* location = getDirectLocation(propertyName);
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    if (thisObject->isHostFunction())
+        return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);

 
 

-        if (!location) {
-            JSObject* prototype = new (exec) JSObject(m_scopeChain.globalObject()->emptyObjectStructure());
-            prototype->putDirect(exec->propertyNames().constructor, this, DontEnum);
-            putDirect(exec->propertyNames().prototype, prototype, DontDelete);
-            location = getDirectLocation(propertyName);
+    if (propertyName == exec->propertyNames().prototype) {
+        VM& vm = exec->vm();
+        PropertyOffset offset = thisObject->getDirectOffset(vm, propertyName);
+        if (!isValidOffset(offset)) {
+            JSObject* prototype = constructEmptyObject(exec);
+            prototype->putDirect(vm, exec->propertyNames().constructor, thisObject, DontEnum);
+            thisObject->putDirect(vm, exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
+            offset = thisObject->getDirectOffset(vm, exec->propertyNames().prototype);
+            ASSERT(isValidOffset(offset));

         }
 
         }
 

-        slot.setValueSlot(this, location, offsetForLocation(location));
+        slot.setValue(thisObject, thisObject->getDirect(offset), offset);

     }
 
     if (propertyName == exec->propertyNames().arguments) {
     }
 
     if (propertyName == exec->propertyNames().arguments) {

-        slot.setCustom(this, argumentsGetter);
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+            if (!result) {
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+                ASSERT(result);
+            }
+            return result;
+        }
+        slot.setCacheableCustom(thisObject, argumentsGetter);

         return true;
     }
 
     if (propertyName == exec->propertyNames().length) {
         return true;
     }
 
     if (propertyName == exec->propertyNames().length) {

-        slot.setCustom(this, lengthGetter);
+        slot.setCacheableCustom(thisObject, lengthGetter);
+        return true;
+    }
+
+    if (propertyName == exec->propertyNames().name) {
+        slot.setCacheableCustom(thisObject, nameGetter);
+        return true;
+    }
+
+    if (propertyName == exec->propertyNames().caller) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+            if (!result) {
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+                ASSERT(result);
+            }
+            return result;
+        }
+        slot.setCacheableCustom(thisObject, callerGetter);
+        return true;
+    }
+
+    return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+}
+
+bool JSFunction::getOwnPropertyDescriptor(JSObject* object, ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (thisObject->isHostFunction())
+        return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+    
+    if (propertyName == exec->propertyNames().prototype) {
+        PropertySlot slot;
+        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
+        return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+    }
+    
+    if (propertyName == exec->propertyNames().arguments) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+            if (!result) {
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+                ASSERT(result);
+            }
+            return result;
+        }
+        descriptor.setDescriptor(exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);
+        return true;
+    }
+    
+    if (propertyName == exec->propertyNames().length) {
+        descriptor.setDescriptor(jsNumber(thisObject->jsExecutable()->parameterCount()), ReadOnly | DontEnum | DontDelete);
+        return true;
+    }
+    
+    if (propertyName == exec->propertyNames().name) {
+        descriptor.setDescriptor(thisObject->jsExecutable()->nameValue(), ReadOnly | DontEnum | DontDelete);

         return true;
     }
 
     if (propertyName == exec->propertyNames().caller) {
         return true;
     }
 
     if (propertyName == exec->propertyNames().caller) {

-        slot.setCustom(this, callerGetter);
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+            if (!result) {
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+                ASSERT(result);
+            }
+            return result;
+        }
+        descriptor.setDescriptor(exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);

         return true;
     }
         return true;
     }

+    
+    return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
+}

 
 

-    return Base::getOwnPropertySlot(exec, propertyName, slot);
+void JSFunction::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (!thisObject->isHostFunction() && (mode == IncludeDontEnumProperties)) {
+        // Make sure prototype has been reified.
+        PropertySlot slot;
+        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, exec->propertyNames().prototype, slot);
+
+        propertyNames.add(exec->propertyNames().arguments);
+        propertyNames.add(exec->propertyNames().caller);
+        propertyNames.add(exec->propertyNames().length);
+        propertyNames.add(exec->propertyNames().name);
+    }
+    Base::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);

 }
 
 }
 

-void JSFunction::put(ExecState* exec, const Identifier& propertyName, JSValuePtr value, PutPropertySlot& slot)
+void JSFunction::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)

 {
 {

-    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length)
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    if (thisObject->isHostFunction()) {
+        Base::put(thisObject, exec, propertyName, value, slot);
+        return;
+    }
+    if (propertyName == exec->propertyNames().prototype) {
+        // Make sure prototype has been reified, such that it can only be overwritten
+        // following the rules set out in ECMA-262 8.12.9.
+        PropertySlot slot;
+        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
+        thisObject->m_allocationProfile.clear();
+        thisObject->m_allocationProfileWatchpoint.notifyWrite();
+        // Don't allow this to be cached, since a [[Put]] must clear m_allocationProfile.
+        PutPropertySlot dontCache;
+        Base::put(thisObject, exec, propertyName, value, dontCache);

         return;
         return;

-    Base::put(exec, propertyName, value, slot);
+    }
+    if (thisObject->jsExecutable()->isStrictMode() && (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().caller)) {
+        // This will trigger the property to be reified, if this is not already the case!
+        bool okay = thisObject->hasProperty(exec, propertyName);
+        ASSERT_UNUSED(okay, okay);
+        Base::put(thisObject, exec, propertyName, value, slot);
+        return;
+    }
+    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().name || propertyName == exec->propertyNames().caller) {
+        if (slot.isStrictMode())
+            throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
+        return;
+    }
+    Base::put(thisObject, exec, propertyName, value, slot);

 }
 
 }
 

-bool JSFunction::deleteProperty(ExecState* exec, const Identifier& propertyName)
+bool JSFunction::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)

 {
 {

-    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length)
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    // For non-host functions, don't let these properties by deleted - except by DefineOwnProperty.
+    if (!thisObject->isHostFunction() && !exec->vm().isInDefineOwnProperty()
+        && (propertyName == exec->propertyNames().arguments
+            || propertyName == exec->propertyNames().length
+            || propertyName == exec->propertyNames().name
+            || propertyName == exec->propertyNames().prototype
+            || propertyName == exec->propertyNames().caller))

         return false;
         return false;

-    return Base::deleteProperty(exec, propertyName);
+    return Base::deleteProperty(thisObject, exec, propertyName);
+}
+
+bool JSFunction::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor, bool throwException)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (thisObject->isHostFunction())
+        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+
+    if (propertyName == exec->propertyNames().prototype) {
+        // Make sure prototype has been reified, such that it can only be overwritten
+        // following the rules set out in ECMA-262 8.12.9.
+        PropertySlot slot;
+        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
+        thisObject->m_allocationProfile.clear();
+        thisObject->m_allocationProfileWatchpoint.notifyWrite();
+        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+    }
+
+    bool valueCheck;
+    if (propertyName == exec->propertyNames().arguments) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            if (!Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor))
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+        }
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject));
+    } else if (propertyName == exec->propertyNames().caller) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            if (!Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor))
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
+            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+        }
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject));
+    } else if (propertyName == exec->propertyNames().length)
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), jsNumber(thisObject->jsExecutable()->parameterCount()));
+    else if (propertyName == exec->propertyNames().name)
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), thisObject->jsExecutable()->nameValue());
+    else
+        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+     
+    if (descriptor.configurablePresent() && descriptor.configurable()) {
+        if (throwException)
+            throwError(exec, createTypeError(exec, ASCIILiteral("Attempting to configurable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.enumerablePresent() && descriptor.enumerable()) {
+        if (throwException)
+            throwError(exec, createTypeError(exec, ASCIILiteral("Attempting to change enumerable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.isAccessorDescriptor()) {
+        if (throwException)
+            throwError(exec, createTypeError(exec, ASCIILiteral("Attempting to change access mechanism for an unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.writablePresent() && descriptor.writable()) {
+        if (throwException)
+            throwError(exec, createTypeError(exec, ASCIILiteral("Attempting to change writable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (!valueCheck) {
+        if (throwException)
+            throwError(exec, createTypeError(exec, ASCIILiteral("Attempting to change value of a readonly property.")));
+        return false;
+    }
+    return true;

 }
 
 // ECMA 13.2.2 [[Construct]]
 }
 
 // ECMA 13.2.2 [[Construct]]

-ConstructType JSFunction::getConstructData(ConstructData& constructData)
+ConstructType JSFunction::getConstructData(JSCell* cell, ConstructData& constructData)

 {
 {

-    constructData.js.functionBody = m_body.get();
-    constructData.js.scopeChain = m_scopeChain.node();
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    if (thisObject->isHostFunction()) {
+        constructData.native.function = thisObject->nativeConstructor();
+        return ConstructTypeHost;
+    }
+    constructData.js.functionExecutable = thisObject->jsExecutable();
+    constructData.js.scope = thisObject->scope();

     return ConstructTypeJS;
 }
 
     return ConstructTypeJS;
 }
 

-JSObject* JSFunction::construct(ExecState* exec, const ArgList& args)
+String getCalculatedDisplayName(CallFrame* callFrame, JSObject* object)

 {
 {

-    Structure* structure;
-    JSValuePtr prototype = get(exec, exec->propertyNames().prototype);
-    if (prototype.isObject())
-        structure = asObject(prototype)->inheritorID();
-    else
-        structure = exec->lexicalGlobalObject()->emptyObjectStructure();
-    JSObject* thisObj = new (exec) JSObject(structure);
-
-    JSValuePtr result = exec->interpreter()->execute(m_body.get(), exec, this, thisObj, args, m_scopeChain.node(), exec->exceptionSlot());
-    if (exec->hadException() || !result.isObject())
-        return thisObj;
-    return asObject(result);
+    if (JSFunction* function = jsDynamicCast<JSFunction*>(object))
+        return function->calculatedDisplayName(callFrame);
+    if (InternalFunction* function = jsDynamicCast<InternalFunction*>(object))
+        return function->calculatedDisplayName(callFrame);
+    return "";

 }
 
 } // namespace JSC
 }
 
 } // namespace JSC