@@ -56,7 +56,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::call(JSGlobalObject* globalObj
     for (int i = 0; i < argumentCount; i++)
         arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));
 
-    JSValueRef exception = 0;
+    JSValueRef exception = nullptr;
     JSValueRef result;
     {
         JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -91,7 +91,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::construct(JSGlobalObject* glob
         for (size_t i = 0; i < argumentCount; ++i)
             arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));
 
-        JSValueRef exception = 0;
+        JSValueRef exception = nullptr;
         JSObjectRef result;
         {
             JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -107,7 +107,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::construct(JSGlobalObject* glob
         return JSValue::encode(toJS(result));
     }
 
-    return JSValue::encode(toJS(JSObjectMake(ctx, jsCast<JSCallbackConstructor*>(constructor)->classRef(), 0)));
+    return JSValue::encode(toJS(JSObjectMake(ctx, jsCast<JSCallbackConstructor*>(constructor)->classRef(), nullptr)));
 }
 
 } // namespace JSC
 
@@ -54,7 +54,7 @@ class JSAPIGlobalObject final : public JSGlobalObject {
 
     static Structure* createStructure(VM& vm, JSValue prototype)
     {
-        auto* result = Structure::create(vm, 0, prototype, TypeInfo(GlobalObjectType, StructureFlags), info());
+        auto* result = Structure::create(vm, nullptr, prototype, TypeInfo(GlobalObjectType, StructureFlags), info());
         result->setTransitionWatchpointIsLikelyToBeFired(true);
         return result;
     }
 
@@ -193,7 +193,7 @@ JSObjectRef JSGetMemoryUsageStatistics(JSContextRef ctx)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
 
     JSGlobalObject* globalObject = toJS(ctx);
 
@@ -175,7 +175,7 @@ bool JSCallbackObject<Parent>::getOwnPropertySlot(JSObject* object, JSGlobalObje
             } else if (JSObjectGetPropertyCallback getProperty = jsClass->getProperty) {
                 if (!propertyNameRef)
                     propertyNameRef = OpaqueJSString::tryCreate(name);
-                JSValueRef exception = 0;
+                JSValueRef exception = nullptr;
                 JSValueRef value;
                 {
                     JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -234,7 +234,7 @@ JSValue JSCallbackObject<Parent>::defaultValue(const JSObject* object, JSGlobalO
 
     for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) {
         if (JSObjectConvertToTypeCallback convertToType = jsClass->convertToType) {
-            JSValueRef exception = 0;
+            JSValueRef exception = nullptr;
             JSValueRef result = convertToType(ctx, thisRef, jsHint, &exception);
             if (exception) {
                 throwException(globalObject, scope, toJS(globalObject, exception));
@@ -265,7 +265,7 @@ bool JSCallbackObject<Parent>::put(JSCell* cell, JSGlobalObject* globalObject, P
             if (JSObjectSetPropertyCallback setProperty = jsClass->setProperty) {
                 if (!propertyNameRef)
                     propertyNameRef = OpaqueJSString::tryCreate(name);
-                JSValueRef exception = 0;
+                JSValueRef exception = nullptr;
                 bool result;
                 {
                     JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -282,7 +282,7 @@ bool JSCallbackObject<Parent>::put(JSCell* cell, JSGlobalObject* globalObject, P
                     if (entry->attributes & kJSPropertyAttributeReadOnly)
                         return false;
                     if (JSObjectSetPropertyCallback setProperty = entry->setProperty) {
-                        JSValueRef exception = 0;
+                        JSValueRef exception = nullptr;
                         bool result;
                         {
                             JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -329,7 +329,7 @@ bool JSCallbackObject<Parent>::putByIndex(JSCell* cell, JSGlobalObject* globalOb
         if (JSObjectSetPropertyCallback setProperty = jsClass->setProperty) {
             if (!propertyNameRef)
                 propertyNameRef = OpaqueJSString::tryCreate(propertyName.impl());
-            JSValueRef exception = 0;
+            JSValueRef exception = nullptr;
             bool result;
             {
                 JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -346,7 +346,7 @@ bool JSCallbackObject<Parent>::putByIndex(JSCell* cell, JSGlobalObject* globalOb
                 if (entry->attributes & kJSPropertyAttributeReadOnly)
                     return false;
                 if (JSObjectSetPropertyCallback setProperty = entry->setProperty) {
-                    JSValueRef exception = 0;
+                    JSValueRef exception = nullptr;
                     bool result;
                     {
                         JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -388,7 +388,7 @@ bool JSCallbackObject<Parent>::deleteProperty(JSCell* cell, JSGlobalObject* glob
             if (JSObjectDeletePropertyCallback deleteProperty = jsClass->deleteProperty) {
                 if (!propertyNameRef)
                     propertyNameRef = OpaqueJSString::tryCreate(name);
-                JSValueRef exception = 0;
+                JSValueRef exception = nullptr;
                 bool result;
                 {
                     JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -461,7 +461,7 @@ EncodedJSValue JSCallbackObject<Parent>::construct(JSGlobalObject* globalObject,
             arguments.reserveInitialCapacity(argumentCount);
             for (size_t i = 0; i < argumentCount; ++i)
                 arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));
-            JSValueRef exception = 0;
+            JSValueRef exception = nullptr;
             JSObject* result;
             {
                 JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -492,7 +492,7 @@ bool JSCallbackObject<Parent>::customHasInstance(JSObject* object, JSGlobalObjec
     for (JSClassRef jsClass = thisObject->classRef(); jsClass; jsClass = jsClass->parentClass) {
         if (JSObjectHasInstanceCallback hasInstance = jsClass->hasInstance) {
             JSValueRef valueRef = toRef(globalObject, value);
-            JSValueRef exception = 0;
+            JSValueRef exception = nullptr;
             bool result;
             {
                 JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -538,7 +538,7 @@ EncodedJSValue JSCallbackObject<Parent>::call(JSGlobalObject* globalObject, Call
             arguments.reserveInitialCapacity(argumentCount);
             for (size_t i = 0; i < argumentCount; ++i)
                 arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));
-            JSValueRef exception = 0;
+            JSValueRef exception = nullptr;
             JSValue result;
             {
                 JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -635,7 +635,7 @@ JSValue JSCallbackObject<Parent>::getStaticValue(JSGlobalObject* globalObject, P
             if (OpaqueJSClassStaticValuesTable* staticValues = jsClass->staticValues(globalObject)) {
                 if (StaticValueEntry* entry = staticValues->get(name)) {
                     if (JSObjectGetPropertyCallback getProperty = entry->getProperty) {
-                        JSValueRef exception = 0;
+                        JSValueRef exception = nullptr;
                         JSValueRef value;
                         {
                             JSLock::DropAllLocks dropAllLocks(globalObject);
@@ -702,7 +702,7 @@ EncodedJSValue JSCallbackObject<Parent>::callbackGetter(JSGlobalObject* globalOb
             if (JSObjectGetPropertyCallback getProperty = jsClass->getProperty) {
                 if (!propertyNameRef)
                     propertyNameRef = OpaqueJSString::tryCreate(name);
-                JSValueRef exception = 0;
+                JSValueRef exception = nullptr;
                 JSValueRef value;
                 {
                     JSLock::DropAllLocks dropAllLocks(globalObject);
 
@@ -38,11 +38,11 @@
 
 using namespace JSC;
 
-const JSClassDefinition kJSClassDefinitionEmpty = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+const JSClassDefinition kJSClassDefinitionEmpty = { 0, 0, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr };
 
 OpaqueJSClass::OpaqueJSClass(const JSClassDefinition* definition, OpaqueJSClass* protoClass) 
     : parentClass(definition->parentClass)
-    , prototypeClass(0)
+    , prototypeClass(nullptr)
     , initialize(definition->initialize)
     , finalize(definition->finalize)
     , hasProperty(definition->hasProperty)
@@ -107,20 +107,20 @@ OpaqueJSClass::~OpaqueJSClass()
 
 Ref<OpaqueJSClass> OpaqueJSClass::createNoAutomaticPrototype(const JSClassDefinition* definition)
 {
-    return adoptRef(*new OpaqueJSClass(definition, 0));
+    return adoptRef(*new OpaqueJSClass(definition, nullptr));
 }
 
 Ref<OpaqueJSClass> OpaqueJSClass::create(const JSClassDefinition* clientDefinition)
 {
     JSClassDefinition definition = *clientDefinition; // Avoid modifying client copy.
 
     JSClassDefinition protoDefinition = kJSClassDefinitionEmpty;
-    protoDefinition.finalize = 0;
+    protoDefinition.finalize = nullptr;
     std::swap(definition.staticFunctions, protoDefinition.staticFunctions); // Move static functions to the prototype.
 
     // We are supposed to use JSClassRetain/Release but since we know that we currently have
     // the only reference to this class object we cheat and use a RefPtr instead.
-    RefPtr<OpaqueJSClass> protoClass = adoptRef(new OpaqueJSClass(&protoDefinition, 0));
+    RefPtr<OpaqueJSClass> protoClass = adoptRef(new OpaqueJSClass(&protoDefinition, nullptr));
     return adoptRef(*new OpaqueJSClass(&definition, protoClass.get()));
 }
 
@@ -182,7 +182,7 @@ JSObject* OpaqueJSClass::prototype(JSGlobalObject* globalObject)
      */
 
     if (!prototypeClass)
-        return 0;
+        return nullptr;
 
     OpaqueJSClassContextData& jsClassData = contextData(globalObject);
 
 
@@ -128,7 +128,7 @@ JSGlobalContextRef JSGlobalContextCreate(JSClassRef globalObjectClass)
     }
 #endif // OS(DARWIN)
 
-    return JSGlobalContextCreateInGroup(0, globalObjectClass);
+    return JSGlobalContextCreateInGroup(nullptr, globalObjectClass);
 }
 
 JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClassRef globalObjectClass)
@@ -148,7 +148,7 @@ JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClass
         return JSGlobalContextRetain(toGlobalRef(globalObject));
     }
 
-    JSGlobalObject* globalObject = JSCallbackObject<JSGlobalObject>::create(vm.get(), globalObjectClass, JSCallbackObject<JSGlobalObject>::createStructure(vm.get(), 0, jsNull()));
+    JSGlobalObject* globalObject = JSCallbackObject<JSGlobalObject>::create(vm.get(), globalObjectClass, JSCallbackObject<JSGlobalObject>::createStructure(vm.get(), nullptr, jsNull()));
     JSValue prototype = globalObjectClass->prototype(globalObject);
     if (!prototype)
         prototype = jsNull();
@@ -187,7 +187,7 @@ JSObjectRef JSContextGetGlobalObject(JSContextRef ctx)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
     JSGlobalObject* globalObject = toJS(ctx);
     VM& vm = globalObject->vm();
@@ -200,7 +200,7 @@ JSContextGroupRef JSContextGetGroup(JSContextRef ctx)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
     JSGlobalObject* globalObject = toJS(ctx);
     return toRef(&globalObject->vm());
@@ -210,7 +210,7 @@ JSGlobalContextRef JSContextGetGlobalContext(JSContextRef ctx)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
     JSGlobalObject* globalObject = toJS(ctx);
     JSLockHolder locker(globalObject);
@@ -222,7 +222,7 @@ JSStringRef JSGlobalContextCopyName(JSGlobalContextRef ctx)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
 
     JSGlobalObject* globalObject = toJS(ctx);
@@ -231,7 +231,7 @@ JSStringRef JSGlobalContextCopyName(JSGlobalContextRef ctx)
 
     String name = globalObject->name();
     if (name.isNull())
-        return 0;
+        return nullptr;
 
     return OpaqueJSString::tryCreate(name).leakRef();
 }
@@ -324,7 +324,7 @@ JSStringRef JSContextCreateBacktrace(JSContextRef ctx, unsigned maxStackSize)
 {
     if (!ctx) {
         ASSERT_NOT_REACHED();
-        return 0;
+        return nullptr;
     }
     JSGlobalObject* globalObject = toJS(ctx);
     VM& vm = globalObject->vm();
Original file line number	Diff line number	Diff line change
`@@ -56,7 +56,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::call(JSGlobalObject* globalObj`
`56`	`56`	`for (int i = 0; i < argumentCount; i++)`
`57`	`57`	`arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));`
`58`	`58`
`59`		`- JSValueRef exception = 0;`
	`59`	`+ JSValueRef exception = nullptr;`
`60`	`60`	`JSValueRef result;`
`61`	`61`	`{`
`62`	`62`	`JSLock::DropAllLocks dropAllLocks(globalObject);`
`@@ -91,7 +91,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::construct(JSGlobalObject* glob`
`91`	`91`	`for (size_t i = 0; i < argumentCount; ++i)`
`92`	`92`	`arguments.uncheckedAppend(toRef(globalObject, callFrame->uncheckedArgument(i)));`
`93`	`93`
`94`		`- JSValueRef exception = 0;`
	`94`	`+ JSValueRef exception = nullptr;`
`95`	`95`	`JSObjectRef result;`
`96`	`96`	`{`
`97`	`97`	`JSLock::DropAllLocks dropAllLocks(globalObject);`
`@@ -107,7 +107,7 @@ EncodedJSValue JSC_HOST_CALL APICallbackFunction::construct(JSGlobalObject* glob`
`107`	`107`	`return JSValue::encode(toJS(result));`
`108`	`108`	`}`
`109`	`109`
`110`		`- return JSValue::encode(toJS(JSObjectMake(ctx, jsCast<JSCallbackConstructor*>(constructor)->classRef(), 0)));`
	`110`	`+ return JSValue::encode(toJS(JSObjectMake(ctx, jsCast<JSCallbackConstructor*>(constructor)->classRef(), nullptr)));`
`111`	`111`	`}`
`112`	`112`
`113`	`113`	`} // namespace JSC`
Original file line number	Diff line number	Diff line change
`@@ -54,7 +54,7 @@ class JSAPIGlobalObject final : public JSGlobalObject {`
`54`	`54`
`55`	`55`	`static Structure* createStructure(VM& vm, JSValue prototype)`
`56`	`56`	`{`
`57`		`- auto* result = Structure::create(vm, 0, prototype, TypeInfo(GlobalObjectType, StructureFlags), info());`
	`57`	`+ auto* result = Structure::create(vm, nullptr, prototype, TypeInfo(GlobalObjectType, StructureFlags), info());`
`58`	`58`	`result->setTransitionWatchpointIsLikelyToBeFired(true);`
`59`	`59`	`return result;`
`60`	`60`	`}`
Original file line number	Diff line number	Diff line change
`@@ -193,7 +193,7 @@ JSObjectRef JSGetMemoryUsageStatistics(JSContextRef ctx)`
`193`	`193`	`{`
`194`	`194`	`if (!ctx) {`
`195`	`195`	`ASSERT_NOT_REACHED();`
`196`		`- return 0;`
	`196`	`+ return nullptr;`
`197`	`197`	`}`
`198`	`198`
`199`	`199`	`JSGlobalObject* globalObject = toJS(ctx);`
Original file line number	Diff line number	Diff line change
`@@ -128,7 +128,7 @@ JSGlobalContextRef JSGlobalContextCreate(JSClassRef globalObjectClass)`
`128`	`128`	`}`
`129`	`129`	`#endif // OS(DARWIN)`
`130`	`130`
`131`		`- return JSGlobalContextCreateInGroup(0, globalObjectClass);`
	`131`	`+ return JSGlobalContextCreateInGroup(nullptr, globalObjectClass);`
`132`	`132`	`}`
`133`	`133`
`134`	`134`	`JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClassRef globalObjectClass)`
`@@ -148,7 +148,7 @@ JSGlobalContextRef JSGlobalContextCreateInGroup(JSContextGroupRef group, JSClass`
`148`	`148`	`return JSGlobalContextRetain(toGlobalRef(globalObject));`
`149`	`149`	`}`
`150`	`150`
`151`		`- JSGlobalObject* globalObject = JSCallbackObject<JSGlobalObject>::create(vm.get(), globalObjectClass, JSCallbackObject<JSGlobalObject>::createStructure(vm.get(), 0, jsNull()));`
	`151`	`+ JSGlobalObject* globalObject = JSCallbackObject<JSGlobalObject>::create(vm.get(), globalObjectClass, JSCallbackObject<JSGlobalObject>::createStructure(vm.get(), nullptr, jsNull()));`
`152`	`152`	`JSValue prototype = globalObjectClass->prototype(globalObject);`
`153`	`153`	`if (!prototype)`
`154`	`154`	`prototype = jsNull();`
`@@ -187,7 +187,7 @@ JSObjectRef JSContextGetGlobalObject(JSContextRef ctx)`
`187`	`187`	`{`
`188`	`188`	`if (!ctx) {`
`189`	`189`	`ASSERT_NOT_REACHED();`
`190`		`- return 0;`
	`190`	`+ return nullptr;`
`191`	`191`	`}`
`192`	`192`	`JSGlobalObject* globalObject = toJS(ctx);`
`193`	`193`	`VM& vm = globalObject->vm();`
`@@ -200,7 +200,7 @@ JSContextGroupRef JSContextGetGroup(JSContextRef ctx)`
`200`	`200`	`{`
`201`	`201`	`if (!ctx) {`
`202`	`202`	`ASSERT_NOT_REACHED();`
`203`		`- return 0;`
	`203`	`+ return nullptr;`
`204`	`204`	`}`
`205`	`205`	`JSGlobalObject* globalObject = toJS(ctx);`
`206`	`206`	`return toRef(&globalObject->vm());`
`@@ -210,7 +210,7 @@ JSGlobalContextRef JSContextGetGlobalContext(JSContextRef ctx)`
`210`	`210`	`{`
`211`	`211`	`if (!ctx) {`
`212`	`212`	`ASSERT_NOT_REACHED();`
`213`		`- return 0;`
	`213`	`+ return nullptr;`
`214`	`214`	`}`
`215`	`215`	`JSGlobalObject* globalObject = toJS(ctx);`
`216`	`216`	`JSLockHolder locker(globalObject);`
`@@ -222,7 +222,7 @@ JSStringRef JSGlobalContextCopyName(JSGlobalContextRef ctx)`
`222`	`222`	`{`
`223`	`223`	`if (!ctx) {`
`224`	`224`	`ASSERT_NOT_REACHED();`
`225`		`- return 0;`
	`225`	`+ return nullptr;`
`226`	`226`	`}`
`227`	`227`
`228`	`228`	`JSGlobalObject* globalObject = toJS(ctx);`
`@@ -231,7 +231,7 @@ JSStringRef JSGlobalContextCopyName(JSGlobalContextRef ctx)`
`231`	`231`
`232`	`232`	`String name = globalObject->name();`
`233`	`233`	`if (name.isNull())`
`234`		`- return 0;`
	`234`	`+ return nullptr;`
`235`	`235`
`236`	`236`	`return OpaqueJSString::tryCreate(name).leakRef();`
`237`	`237`	`}`
`@@ -324,7 +324,7 @@ JSStringRef JSContextCreateBacktrace(JSContextRef ctx, unsigned maxStackSize)`
`324`	`324`	`{`
`325`	`325`	`if (!ctx) {`
`326`	`326`	`ASSERT_NOT_REACHED();`
`327`		`- return 0;`
	`327`	`+ return nullptr;`
`328`	`328`	`}`
`329`	`329`	`JSGlobalObject* globalObject = toJS(ctx);`
`330`	`330`	`VM& vm = globalObject->vm();`