webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 578 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/JSFunction.cpp b/Source/JavaScriptCore/runtime/JSFunction.cpp
new file mode 100644
index 000000000..0f7354ed7
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/JSFunction.cpp
@@ -0,0 +1,578 @@
+/*
+ *  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, 2009, 2015 Apple Inc. All rights reserved.
+ *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
+ *  Copyright (C) 2007 Maks Orlovich
+ *  Copyright (C) 2015 Canon Inc. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "config.h"
+#include "JSFunction.h"
+
+#include "ClonedArguments.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 "JSCInlines.h"
+#include "JSFunctionInlines.h"
+#include "JSGlobalObject.h"
+#include "JSNotAnObject.h"
+#include "Interpreter.h"
+#include "ObjectConstructor.h"
+#include "ObjectPrototype.h"
+#include "Parser.h"
+#include "PropertyNameArray.h"
+#include "StackVisitor.h"
+
+namespace JSC {
+
+EncodedJSValue JSC_HOST_CALL callHostFunctionAsConstructor(ExecState* exec)
+{
+    return throwVMError(exec, createNotAConstructorError(exec, exec->callee()));
+}
+
+const ClassInfo JSFunction::s_info = { "Function", &Base::s_info, 0, CREATE_METHOD_TABLE(JSFunction) };
+
+bool JSFunction::isHostFunctionNonInline() const
+{
+    return isHostFunction();
+}
+
+JSFunction* JSFunction::create(VM& vm, FunctionExecutable* executable, JSScope* scope)
+{
+    JSFunction* result = createImpl(vm, executable, scope);
+    executable->singletonFunction()->notifyWrite(vm, result, "Allocating a function");
+    return result;
+}
+
+static inline NativeExecutable* getNativeExecutable(VM& vm, NativeFunction nativeFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)
+{
+#if !ENABLE(JIT)
+    UNUSED_PARAM(intrinsic);
+#else
+    if (intrinsic != NoIntrinsic && vm.canUseJIT()) {
+        ASSERT(nativeConstructor == callHostFunctionAsConstructor);
+        return vm.getHostFunction(nativeFunction, intrinsic);
+    }
+#endif
+    return vm.getHostFunction(nativeFunction, nativeConstructor);
+}
+
+JSFunction* JSFunction::create(VM& vm, JSGlobalObject* globalObject, int length, const String& name, NativeFunction nativeFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)
+{
+    NativeExecutable* executable = getNativeExecutable(vm, nativeFunction, intrinsic, 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;
+}
+
+class JSStdFunction : public JSFunction {
+public:
+    JSStdFunction(VM& vm, JSGlobalObject* object, Structure* structure, NativeStdFunction&& function)
+        : JSFunction(vm, object, structure)
+        , stdFunction(WTF::move(function)) { }
+
+    NativeStdFunction stdFunction;
+};
+
+static EncodedJSValue JSC_HOST_CALL runStdFunction(ExecState* state)
+{
+    JSStdFunction* jsFunction = jsCast<JSStdFunction*>(state->callee());
+    ASSERT(jsFunction);
+    return jsFunction->stdFunction(state);
+}
+
+JSFunction* JSFunction::create(VM& vm, JSGlobalObject* globalObject, int length, const String& name, NativeStdFunction&& nativeStdFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)
+{
+    NativeExecutable* executable = getNativeExecutable(vm, runStdFunction, intrinsic, nativeConstructor);
+    JSStdFunction* function = new (NotNull, allocateCell<JSStdFunction>(vm.heap)) JSStdFunction(vm, globalObject, globalObject->functionStructure(), WTF::move(nativeStdFunction));
+    // Can't do this during initialization because getHostFunction might do a GC allocation.
+    function->finishCreation(vm, executable, length, name);
+    return function;
+}
+
+JSFunction::JSFunction(VM& vm, JSGlobalObject* globalObject, Structure* structure)
+    : Base(vm, globalObject, structure)
+    , m_executable()
+{
+}
+
+void JSFunction::finishCreation(VM& vm, NativeExecutable* executable, int length, const String& name)
+{
+    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);
+}
+
+JSFunction* JSFunction::createBuiltinFunction(VM& vm, FunctionExecutable* executable, JSGlobalObject* globalObject)
+{
+    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;
+}
+
+JSFunction* JSFunction::createBuiltinFunction(VM& vm, FunctionExecutable* executable, JSGlobalObject* globalObject, const String& name)
+{
+    JSFunction* function = create(vm, executable, globalObject);
+    function->putDirect(vm, vm.propertyNames->name, jsString(&vm, name), DontDelete | ReadOnly | DontEnum);
+    function->putDirect(vm, vm.propertyNames->length, jsNumber(executable->parameterCount()), DontDelete | ReadOnly | DontEnum);
+    return function;
+}
+
+FunctionRareData* JSFunction::allocateAndInitializeRareData(ExecState* exec, size_t inlineCapacity)
+{
+    ASSERT(!m_rareData);
+    VM& vm = exec->vm();
+    JSObject* prototype = jsDynamicCast<JSObject*>(get(exec, vm.propertyNames->prototype));
+    if (!prototype)
+        prototype = globalObject()->objectPrototype();
+    FunctionRareData* rareData = FunctionRareData::create(vm, prototype, inlineCapacity);
+
+    // A DFG compilation thread may be trying to read the rare data
+    // We want to ensure that it sees it properly allocated
+    WTF::storeStoreFence();
+
+    m_rareData.set(vm, this, rareData);
+    return m_rareData.get();
+}
+
+FunctionRareData* JSFunction::initializeRareData(ExecState* exec, size_t inlineCapacity)
+{
+    ASSERT(!!m_rareData);
+    VM& vm = exec->vm();
+    JSObject* prototype = jsDynamicCast<JSObject*>(get(exec, vm.propertyNames->prototype));
+    if (!prototype)
+        prototype = globalObject()->objectPrototype();
+    m_rareData->initialize(globalObject()->vm(), prototype, inlineCapacity);
+    return m_rareData.get();
+}
+
+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());
+    Base::visitChildren(thisObject, visitor);
+
+    visitor.append(&thisObject->m_executable);
+    if (thisObject->m_rareData)
+        visitor.append(&thisObject->m_rareData);
+}
+
+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;
+}
+
+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)
+{
+    RetrieveArgumentsFunctor functor(functionObj);
+    exec->iterate(functor);
+    return functor.result();
+}
+
+EncodedJSValue JSFunction::argumentsGetter(ExecState* exec, JSObject* slotBase, EncodedJSValue, PropertyName)
+{
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+
+    return JSValue::encode(retrieveArguments(exec, thisObj));
+}
+
+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 = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    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())) {
+        // It isn't a JSFunction, but if it is a JSCallee from a program or call eval, return null.
+        if (jsDynamicCast<JSCallee*>(caller))
+            return JSValue::encode(jsNull());
+        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")));
+}
+
+EncodedJSValue JSFunction::lengthGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
+{
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return JSValue::encode(jsNumber(thisObj->jsExecutable()->parameterCount()));
+}
+
+EncodedJSValue JSFunction::nameGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
+{
+    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
+    ASSERT(!thisObj->isHostFunction());
+    return JSValue::encode(thisObj->jsExecutable()->nameValue());
+}
+
+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 (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.setValue(thisObject, attributes, thisObject->getDirect(offset), offset);
+    }
+
+    if (propertyName == exec->propertyNames().arguments) {
+        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.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) {
+        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(thisObject, exec, propertyName, slot);
+}
+
+void JSFunction::getOwnNonIndexPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
+{
+    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::getOwnNonIndexPropertyNames(thisObject, exec, propertyNames, mode);
+}
+
+void JSFunction::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& 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);
+        if (thisObject->m_rareData)
+            thisObject->m_rareData->clear("Store to prototype property of a function");
+        // Don't allow this to be cached, since a [[Put]] must clear m_rareData.
+        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 || 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(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::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool throwException)
+{
+    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);
+        if (thisObject->m_rareData)
+            thisObject->m_rareData->clear("Store to prototype property of a function");
+        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 change 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 true;
+}
+
+// ECMA 13.2.2 [[Construct]]
+ConstructType JSFunction::getConstructData(JSCell* cell, ConstructData& constructData)
+{
+    JSFunction* thisObject = jsCast<JSFunction*>(cell);
+
+    if (thisObject->isHostFunction()) {
+        constructData.native.function = thisObject->nativeConstructor();
+        return ConstructTypeHost;
+    }
+
+    FunctionExecutable* functionExecutable = thisObject->jsExecutable();
+    if (functionExecutable->constructAbility() == ConstructAbility::CannotConstruct)
+        return ConstructTypeNone;
+
+    constructData.js.functionExecutable = functionExecutable;
+    constructData.js.scope = thisObject->scope();
+    return ConstructTypeJS;
+}
+
+String getCalculatedDisplayName(CallFrame* callFrame, JSObject* object)
+{
+    if (JSFunction* function = jsDynamicCast<JSFunction*>(object))
+        return function->calculatedDisplayName(callFrame);
+    if (InternalFunction* function = jsDynamicCast<InternalFunction*>(object))
+        return function->calculatedDisplayName(callFrame);
+    return "";
+}
+
+} // namespace JSC