X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/f9bf01c6616d5ddcf65b13b33cedf9e387ff7a63..cb9aa2694aba0ae4f946ed34b8e0f6c99c1cfe44:/runtime/JSFunction.cpp

diff --git a/runtime/JSFunction.cpp b/runtime/JSFunction.cpp
index d213b4a..0f47ac9 100644
--- a/runtime/JSFunction.cpp
+++ b/runtime/JSFunction.cpp
@@ -25,245 +25,511 @@
 #include "config.h"
 #include "JSFunction.h"
 
+#include "Arguments.h"
 #include "CodeBlock.h"
 #include "CommonIdentifiers.h"
 #include "CallFrame.h"
+#include "ExceptionHelpers.h"
 #include "FunctionPrototype.h"
+#include "GetterSetter.h"
+#include "JSArray.h"
+#include "JSBoundFunction.h"
+#include "JSFunctionInlines.h"
 #include "JSGlobalObject.h"
+#include "JSNameScope.h" 
+#include "JSNotAnObject.h"
 #include "Interpreter.h"
+#include "ObjectConstructor.h"
 #include "ObjectPrototype.h"
+#include "JSCInlines.h"
 #include "Parser.h"
 #include "PropertyNameArray.h"
-#include "ScopeChainMark.h"
-
-using namespace WTF;
-using namespace Unicode;
+#include "StackVisitor.h"
 
 namespace JSC {
 
-ASSERT_CLASS_FITS_IN_CELL(JSFunction);
+EncodedJSValue JSC_HOST_CALL callHostFunctionAsConstructor(ExecState* exec)
+{
+    return throwVMError(exec, createNotAConstructorError(exec, exec->callee()));
+}
 
-const ClassInfo JSFunction::info = { "Function", &InternalFunction::info, 0, 0 };
+const ClassInfo JSFunction::s_info = { "Function", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(JSFunction) };
 
 bool JSFunction::isHostFunctionNonInline() const
 {
     return isHostFunction();
 }
 
-JSFunction::JSFunction(NonNullPassRefPtr<Structure> structure)
-    : Base(structure)
-    , m_executable(adoptRef(new VPtrHackExecutable()))
+JSFunction* JSFunction::create(VM& vm, JSGlobalObject* globalObject, int length, const String& name, NativeFunction nativeFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)
 {
+    NativeExecutable* executable;
+#if !ENABLE(JIT)
+    UNUSED_PARAM(intrinsic);
+#else
+    if (intrinsic != NoIntrinsic && vm.canUseJIT()) {
+        ASSERT(nativeConstructor == callHostFunctionAsConstructor);
+        executable = vm.getHostFunction(nativeFunction, intrinsic);
+    } else
+#endif
+        executable = vm.getHostFunction(nativeFunction, nativeConstructor);
+
+    JSFunction* function = new (NotNull, allocateCell<JSFunction>(vm.heap)) JSFunction(vm, globalObject, globalObject->functionStructure());
+    // Can't do this during initialization because getHostFunction might do a GC allocation.
+    function->finishCreation(vm, executable, length, name);
+    return function;
 }
 
-JSFunction::JSFunction(ExecState* exec, NonNullPassRefPtr<Structure> structure, int length, const Identifier& name, NativeFunction func)
-    : Base(&exec->globalData(), structure, name)
-#if ENABLE(JIT)
-    , m_executable(adoptRef(new NativeExecutable(exec)))
-#endif
+void JSFunction::destroy(JSCell* cell)
 {
-#if ENABLE(JIT)
-    setNativeFunction(func);
-    putDirect(exec->propertyNames().length, jsNumber(exec, length), DontDelete | ReadOnly | DontEnum);
-#else
-    UNUSED_PARAM(length);
-    UNUSED_PARAM(func);
-    ASSERT_NOT_REACHED();
-#endif
+    static_cast<JSFunction*>(cell)->JSFunction::~JSFunction();
 }
 
-JSFunction::JSFunction(ExecState* exec, NonNullPassRefPtr<FunctionExecutable> executable, ScopeChainNode* scopeChainNode)
-    : Base(&exec->globalData(), exec->lexicalGlobalObject()->functionStructure(), executable->name())
-    , m_executable(executable)
+JSFunction::JSFunction(VM& vm, JSGlobalObject* globalObject, Structure* structure)
+    : Base(vm, structure)
+    , m_executable()
+    , m_scope(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(ClearWatchpoint)
 {
-    setScopeChain(scopeChainNode);
 }
 
-JSFunction::~JSFunction()
+void JSFunction::finishCreation(VM& vm, NativeExecutable* executable, int length, const String& name)
 {
-    ASSERT(vptr() == JSGlobalData::jsFunctionVPtr);
-
-    // 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 (!isHostFunction()) {
-#if ENABLE(JIT_OPTIMIZE_CALL)
-        ASSERT(m_executable);
-        if (jsExecutable()->isGenerated())
-            jsExecutable()->generatedBytecode().unlinkCallers();
-#endif
-        scopeChain().~ScopeChain(); // FIXME: Don't we need to do this in the interpreter too?
-    }
+    Base::finishCreation(vm);
+    ASSERT(inherits(info()));
+    m_executable.set(vm, this, executable);
+    putDirect(vm, vm.propertyNames->name, jsString(&vm, name), DontDelete | ReadOnly | DontEnum);
+    putDirect(vm, vm.propertyNames->length, jsNumber(length), DontDelete | ReadOnly | DontEnum);
 }
 
-void JSFunction::markChildren(MarkStack& markStack)
+void JSFunction::addNameScopeIfNeeded(VM& vm)
 {
-    Base::markChildren(markStack);
-    if (!isHostFunction()) {
-        jsExecutable()->markAggregate(markStack);
-        scopeChain().markAggregate(markStack);
-    }
+    FunctionExecutable* executable = jsCast<FunctionExecutable*>(m_executable.get());
+    if (!functionNameIsInScope(executable->name(), executable->functionMode()))
+        return;
+    if (!functionNameScopeIsDynamic(executable->usesEval(), executable->isStrictMode()))
+        return;
+    m_scope.set(vm, this, JSNameScope::create(vm, m_scope->globalObject(), executable->name(), this, ReadOnly | DontDelete, m_scope.get()));
 }
 
-CallType JSFunction::getCallData(CallData& callData)
+JSFunction* JSFunction::createBuiltinFunction(VM& vm, FunctionExecutable* executable, JSGlobalObject* globalObject)
 {
-    if (isHostFunction()) {
-        callData.native.function = nativeFunction();
+    JSFunction* function = create(vm, executable, globalObject);
+    function->putDirect(vm, vm.propertyNames->name, jsString(&vm, executable->name().string()), DontDelete | ReadOnly | DontEnum);
+    function->putDirect(vm, vm.propertyNames->length, jsNumber(executable->parameterCount()), DontDelete | ReadOnly | DontEnum);
+    return function;
+}
+
+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();
+}
+
+const String JSFunction::calculatedDisplayName(ExecState* exec)
+{
+    const String explicitName = displayName(exec);
+    
+    if (!explicitName.isEmpty())
+        return explicitName;
+    
+    const String actualName = name(exec);
+    if (!actualName.isEmpty() || isHostOrBuiltinFunction())
+        return actualName;
+    
+    return jsExecutable()->inferredName().string();
+}
+
+const SourceCode* JSFunction::sourceCode() const
+{
+    if (isHostOrBuiltinFunction())
+        return 0;
+    return &jsExecutable()->source();
+}
+    
+void JSFunction::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, 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 = jsExecutable();
-    callData.js.scopeChain = scopeChain().node();
+    callData.js.functionExecutable = thisObject->jsExecutable();
+    callData.js.scope = thisObject->scope();
     return CallTypeJS;
 }
 
-JSValue JSFunction::call(ExecState* exec, JSValue thisValue, const ArgList& args)
+class RetrieveArgumentsFunctor {
+public:
+    RetrieveArgumentsFunctor(JSFunction* functionObj)
+        : m_targetCallee(jsDynamicCast<JSObject*>(functionObj))
+        , m_result(jsNull())
+    {
+    }
+
+    JSValue result() const { return m_result; }
+
+    StackVisitor::Status operator()(StackVisitor& visitor)
+    {
+        JSObject* callee = visitor->callee();
+        if (callee != m_targetCallee)
+            return StackVisitor::Continue;
+
+        m_result = JSValue(visitor->createArguments());
+        return StackVisitor::Done;
+    }
+
+private:
+    JSObject* m_targetCallee;
+    JSValue m_result;
+};
+
+static JSValue retrieveArguments(ExecState* exec, JSFunction* functionObj)
 {
-    ASSERT(!isHostFunction());
-    return exec->interpreter()->execute(jsExecutable(), exec, this, thisValue.toThisObject(exec), args, scopeChain().node(), exec->exceptionSlot());
+    RetrieveArgumentsFunctor functor(functionObj);
+    exec->iterate(functor);
+    return functor.result();
 }
 
-JSValue JSFunction::argumentsGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+EncodedJSValue JSFunction::argumentsGetter(ExecState* exec, JSObject* slotBase, EncodedJSValue, PropertyName)
 {
-    JSFunction* thisObj = asFunction(slot.slotBase());
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
     ASSERT(!thisObj->isHostFunction());
-    return exec->interpreter()->retrieveArguments(exec, thisObj);
+
+    return JSValue::encode(retrieveArguments(exec, thisObj));
 }
 
-JSValue JSFunction::callerGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+class RetrieveCallerFunctionFunctor {
+public:
+    RetrieveCallerFunctionFunctor(JSFunction* functionObj)
+        : m_targetCallee(jsDynamicCast<JSObject*>(functionObj))
+        , m_hasFoundFrame(false)
+        , m_hasSkippedToCallerFrame(false)
+        , m_result(jsNull())
+    {
+    }
+
+    JSValue result() const { return m_result; }
+
+    StackVisitor::Status operator()(StackVisitor& visitor)
+    {
+        JSObject* callee = visitor->callee();
+
+        if (callee && callee->inherits(JSBoundFunction::info()))
+            return StackVisitor::Continue;
+
+        if (!m_hasFoundFrame && (callee != m_targetCallee))
+            return StackVisitor::Continue;
+
+        m_hasFoundFrame = true;
+        if (!m_hasSkippedToCallerFrame) {
+            m_hasSkippedToCallerFrame = true;
+            return StackVisitor::Continue;
+        }
+
+        if (callee)
+            m_result = callee;
+        return StackVisitor::Done;
+    }
+
+private:
+    JSObject* m_targetCallee;
+    bool m_hasFoundFrame;
+    bool m_hasSkippedToCallerFrame;
+    JSValue m_result;
+};
+
+static JSValue retrieveCallerFunction(ExecState* exec, JSFunction* functionObj)
+{
+    RetrieveCallerFunctionFunctor functor(functionObj);
+    exec->iterate(functor);
+    return functor.result();
+}
+
+EncodedJSValue JSFunction::callerGetter(ExecState* exec, JSObject* slotBase, EncodedJSValue, PropertyName)
 {
-    JSFunction* thisObj = asFunction(slot.slotBase());
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
     ASSERT(!thisObj->isHostFunction());
-    return exec->interpreter()->retrieveCaller(exec, thisObj);
+    JSValue caller = retrieveCallerFunction(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::info()))
+        return JSValue::encode(caller);
+    JSFunction* function = jsCast<JSFunction*>(caller);
+    if (function->isHostOrBuiltinFunction() || !function->jsExecutable()->isStrictMode())
+        return JSValue::encode(caller);
+    return JSValue::encode(throwTypeError(exec, ASCIILiteral("Function.caller used to retrieve strict caller")));
 }
 
-JSValue JSFunction::lengthGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
+EncodedJSValue JSFunction::lengthGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
 {
-    JSFunction* thisObj = asFunction(slot.slotBase());
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
     ASSERT(!thisObj->isHostFunction());
-    return jsNumber(exec, thisObj->jsExecutable()->parameterCount());
+    return JSValue::encode(jsNumber(thisObj->jsExecutable()->parameterCount()));
 }
 
-bool JSFunction::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
+EncodedJSValue JSFunction::nameGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
 {
-    if (isHostFunction())
-        return Base::getOwnPropertySlot(exec, propertyName, slot);
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return JSValue::encode(thisObj->jsExecutable()->nameValue());
+}
 
-    if (propertyName == exec->propertyNames().prototype) {
-        JSValue* location = getDirectLocation(propertyName);
+bool JSFunction::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (thisObject->isHostOrBuiltinFunction())
+        return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 
-        if (!location) {
-            JSObject* prototype = new (exec) JSObject(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();
+        unsigned attributes;
+        PropertyOffset offset = thisObject->getDirectOffset(vm, propertyName, attributes);
+        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, attributes);
+            ASSERT(isValidOffset(offset));
         }
 
-        slot.setValueSlot(this, location, offsetForLocation(location));
+        slot.setValue(thisObject, attributes, thisObject->getDirect(offset), offset);
     }
 
     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->vm()), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+                ASSERT(result);
+            }
+            return result;
+        }
+        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, argumentsGetter);
         return true;
     }
 
     if (propertyName == exec->propertyNames().length) {
-        slot.setCustom(this, lengthGetter);
+        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, lengthGetter);
+        return true;
+    }
+
+    if (propertyName == exec->propertyNames().name) {
+        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, nameGetter);
         return true;
     }
 
     if (propertyName == exec->propertyNames().caller) {
-        slot.setCustom(this, callerGetter);
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+            if (!result) {
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
+                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
+                ASSERT(result);
+            }
+            return result;
+        }
+        slot.setCacheableCustom(thisObject, ReadOnly | DontEnum | DontDelete, callerGetter);
         return true;
     }
 
-    return Base::getOwnPropertySlot(exec, propertyName, slot);
+    return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 }
 
-    bool JSFunction::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
-    {
-        if (isHostFunction())
-            return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
-        
-        if (propertyName == exec->propertyNames().prototype) {
-            PropertySlot slot;
-            getOwnPropertySlot(exec, propertyName, slot);
-            return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
-        }
-        
-        if (propertyName == exec->propertyNames().arguments) {
-            descriptor.setDescriptor(exec->interpreter()->retrieveArguments(exec, this), ReadOnly | DontEnum | DontDelete);
-            return true;
-        }
-        
-        if (propertyName == exec->propertyNames().length) {
-            descriptor.setDescriptor(jsNumber(exec, jsExecutable()->parameterCount()), ReadOnly | DontEnum | DontDelete);
-            return true;
-        }
-        
-        if (propertyName == exec->propertyNames().caller) {
-            descriptor.setDescriptor(exec->interpreter()->retrieveCaller(exec, this), ReadOnly | DontEnum | DontDelete);
-            return true;
-        }
-        
-        return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
-    }
-    
-void JSFunction::getOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
+void JSFunction::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 {
-    if (!isHostFunction() && (mode == IncludeDontEnumProperties)) {
-        propertyNames.add(exec->propertyNames().arguments);
-        propertyNames.add(exec->propertyNames().callee);
-        propertyNames.add(exec->propertyNames().caller);
-        propertyNames.add(exec->propertyNames().length);
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (!thisObject->isHostOrBuiltinFunction() && (mode == IncludeDontEnumProperties)) {
+        VM& vm = exec->vm();
+        // Make sure prototype has been reified.
+        PropertySlot slot(thisObject);
+        thisObject->methodTable(vm)->getOwnPropertySlot(thisObject, exec, vm.propertyNames->prototype, slot);
+
+        propertyNames.add(vm.propertyNames->arguments);
+        propertyNames.add(vm.propertyNames->caller);
+        propertyNames.add(vm.propertyNames->length);
+        propertyNames.add(vm.propertyNames->name);
     }
-    Base::getOwnPropertyNames(exec, propertyNames, mode);
+    Base::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
 }
 
-void JSFunction::put(ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
+void JSFunction::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 {
-    if (isHostFunction()) {
-        Base::put(exec, propertyName, value, slot);
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    if (thisObject->isHostOrBuiltinFunction()) {
+        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);
+        thisObject->methodTable(exec->vm())->getOwnPropertySlot(thisObject, exec, propertyName, slot);
+        thisObject->m_allocationProfile.clear();
+        thisObject->m_allocationProfileWatchpoint.fireAll();
+        // Don't allow this to be cached, since a [[Put]] must clear m_allocationProfile.
+        PutPropertySlot dontCache(thisObject);
+        Base::put(thisObject, exec, propertyName, value, dontCache);
+        return;
+    }
+    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)
+    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(exec, propertyName, value, slot);
+    }
+    Base::put(thisObject, exec, propertyName, value, slot);
+}
+
+bool JSFunction::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+    // For non-host functions, don't let these properties by deleted - except by DefineOwnProperty.
+    if (!thisObject->isHostOrBuiltinFunction() && !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 Base::deleteProperty(thisObject, exec, propertyName);
 }
 
-bool JSFunction::deleteProperty(ExecState* exec, const Identifier& propertyName)
+bool JSFunction::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool throwException)
 {
-    if (isHostFunction())
-        return Base::deleteProperty(exec, propertyName);
-    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length)
+    JSFunction* thisObject = jsCast<JSFunction*>(object);
+    if (thisObject->isHostOrBuiltinFunction())
+        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);
+        thisObject->methodTable(exec->vm())->getOwnPropertySlot(thisObject, exec, propertyName, slot);
+        thisObject->m_allocationProfile.clear();
+        thisObject->m_allocationProfileWatchpoint.fireAll();
+        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+    }
+
+    bool valueCheck;
+    if (propertyName == exec->propertyNames().arguments) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            PropertySlot slot(thisObject);
+            if (!Base::getOwnPropertySlot(thisObject, exec, propertyName, slot))
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
+            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+        }
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), retrieveArguments(exec, thisObject));
+    } else if (propertyName == exec->propertyNames().caller) {
+        if (thisObject->jsExecutable()->isStrictMode()) {
+            PropertySlot slot(thisObject);
+            if (!Base::getOwnPropertySlot(thisObject, exec, propertyName, slot))
+                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec->vm()), DontDelete | DontEnum | Accessor);
+            return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
+        }
+        valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), retrieveCallerFunction(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)
+            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to configurable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.enumerablePresent() && descriptor.enumerable()) {
+        if (throwException)
+            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change enumerable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.isAccessorDescriptor()) {
+        if (throwException)
+            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change access mechanism for an unconfigurable property.")));
+        return false;
+    }
+    if (descriptor.writablePresent() && descriptor.writable()) {
+        if (throwException)
+            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change writable attribute of unconfigurable property.")));
+        return false;
+    }
+    if (!valueCheck) {
+        if (throwException)
+            exec->vm().throwException(exec, createTypeError(exec, ASCIILiteral("Attempting to change value of a readonly property.")));
         return false;
-    return Base::deleteProperty(exec, propertyName);
+    }
+    return true;
 }
 
 // ECMA 13.2.2 [[Construct]]
-ConstructType JSFunction::getConstructData(ConstructData& constructData)
+ConstructType JSFunction::getConstructData(JSCell* cell, ConstructData& constructData)
 {
-    if (isHostFunction())
-        return ConstructTypeNone;
-    constructData.js.functionExecutable = jsExecutable();
-    constructData.js.scopeChain = 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;
 }
 
-JSObject* JSFunction::construct(ExecState* exec, const ArgList& args)
+String getCalculatedDisplayName(CallFrame* callFrame, JSObject* object)
 {
-    ASSERT(!isHostFunction());
-    Structure* structure;
-    JSValue prototype = get(exec, exec->propertyNames().prototype);
-    if (prototype.isObject())
-        structure = asObject(prototype)->inheritorID();
-    else
-        structure = exec->lexicalGlobalObject()->emptyObjectStructure();
-    JSObject* thisObj = new (exec) JSObject(structure);
-
-    JSValue result = exec->interpreter()->execute(jsExecutable(), exec, this, thisObj, args, 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