C++ JSValue::isString方法代码示例

// ECMA-262 5.1, 15.11.4.4
EncodedJSValue JSC_HOST_CALL errorProtoFuncToString(ExecState* exec)
{
    VM& vm = exec->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // 1. Let O be the this value.
    JSValue thisValue = exec->thisValue();

    // 2. If Type(O) is not Object, throw a TypeError exception.
    if (!thisValue.isObject())
        return throwVMTypeError(exec, scope);
    JSObject* thisObj = asObject(thisValue);

    // Guard against recursion!
    StringRecursionChecker checker(exec, thisObj);
    ASSERT(!scope.exception() || checker.earlyReturnValue());
    if (JSValue earlyReturnValue = checker.earlyReturnValue())
        return JSValue::encode(earlyReturnValue);

    // 3. Let name be the result of calling the [[Get]] internal method of O with argument "name".
    JSValue name = thisObj->get(exec, exec->propertyNames().name);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    // 4. If name is undefined, then let name be "Error"; else let name be ToString(name).
    String nameString;
    if (name.isUndefined())
        nameString = ASCIILiteral("Error");
    else {
        nameString = name.toWTFString(exec);
        RETURN_IF_EXCEPTION(scope, encodedJSValue());
    }

    // 5. Let msg be the result of calling the [[Get]] internal method of O with argument "message".
    JSValue message = thisObj->get(exec, exec->propertyNames().message);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    // (sic)
    // 6. If msg is undefined, then let msg be the empty String; else let msg be ToString(msg).
    // 7. If msg is undefined, then let msg be the empty String; else let msg be ToString(msg).
    String messageString;
    if (message.isUndefined())
        messageString = String();
    else {
        messageString = message.toWTFString(exec);
        RETURN_IF_EXCEPTION(scope, encodedJSValue());
    }

    // 8. If name is the empty String, return msg.
    if (!nameString.length())
        return JSValue::encode(message.isString() ? message : jsString(exec, messageString));

    // 9. If msg is the empty String, return name.
    if (!messageString.length())
        return JSValue::encode(name.isString() ? name : jsString(exec, nameString));

    // 10. Return the result of concatenating name, ":", a single space character, and msg.
    scope.release();
    return JSValue::encode(jsMakeNontrivialString(exec, nameString, ": ", messageString));
}

static std::error_code getDomainList(ExecState& exec, const JSObject* arrayObject, Vector<String>& vector)
{
    VM& vm = exec.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    ASSERT(vector.isEmpty());
    if (!arrayObject || !isJSArray(arrayObject))
        return ContentExtensionError::JSONInvalidDomainList;
    const JSArray* array = jsCast<const JSArray*>(arrayObject);
    
    unsigned length = array->length();
    for (unsigned i = 0; i < length; ++i) {
        const JSValue value = array->getIndex(&exec, i);
        if (scope.exception() || !value.isString())
            return ContentExtensionError::JSONInvalidDomainList;
        
        // Domains should be punycode encoded lower case.
        const String& domain = jsCast<JSString*>(value)->value(&exec);
        if (domain.isEmpty())
            return ContentExtensionError::JSONInvalidDomainList;
        if (!containsOnlyASCIIWithNoUppercase(domain))
            return ContentExtensionError::JSONDomainNotLowerCaseASCII;
        vector.append(domain);
    }
    return { };
}

RuntimeType runtimeTypeForValue(JSValue value)
{
    if (UNLIKELY(!value))
        return TypeNothing;

    if (value.isUndefined())
        return TypeUndefined;
    if (value.isNull())
        return TypeNull;
    if (value.isAnyInt())
        return TypeAnyInt;
    if (value.isNumber())
        return TypeNumber;
    if (value.isString())
        return TypeString;
    if (value.isBoolean())
        return TypeBoolean;
    if (value.isObject())
        return TypeObject;
    if (value.isFunction())
        return TypeFunction;
    if (value.isSymbol())
        return TypeSymbol;

    return TypeNothing;
}

RuntimeType TypeSet::getRuntimeTypeForValue(JSValue v)
{
    RuntimeType ret;
    if (v.isFunction())
        ret = TypeFunction;
    else if (v.isUndefined())
        ret = TypeUndefined;
    else if (v.isNull())
        ret = TypeNull;
    else if (v.isBoolean())
        ret = TypeBoolean;
    else if (v.isMachineInt())
        ret = TypeMachineInt;
    else if (v.isNumber())
        ret = TypeNumber;
    else if (v.isString())
        ret = TypeString;
    else if (v.isPrimitive())
        ret = TypePrimitive;
    else if (v.isObject())
        ret = TypeObject;
    else
        CRASH();

    return ret;
}

EncodedJSValue JIT_OPERATION operationGetByValCell(ExecState* exec, JSCell* base, EncodedJSValue encodedProperty)
{
    VM& vm = exec->vm();
    NativeCallFrameTracer tracer(&vm, exec);
    
    JSValue property = JSValue::decode(encodedProperty);

    if (property.isUInt32())
        return getByVal(exec, base, property.asUInt32());
    if (property.isDouble()) {
        double propertyAsDouble = property.asDouble();
        uint32_t propertyAsUInt32 = static_cast<uint32_t>(propertyAsDouble);
        if (propertyAsUInt32 == propertyAsDouble)
            return getByVal(exec, base, propertyAsUInt32);
    } else if (property.isString()) {
        Structure& structure = *base->structure(vm);
        if (JSCell::canUseFastGetOwnProperty(structure)) {
            if (AtomicStringImpl* existingAtomicString = asString(property)->toExistingAtomicString(exec)) {
                if (JSValue result = base->fastGetOwnProperty(vm, structure, existingAtomicString))
                    return JSValue::encode(result);
            }
        }
    }

    PropertyName propertyName = property.toPropertyKey(exec);
    return JSValue::encode(JSValue(base).get(exec, propertyName));
}

EncodedJSValue DFG_OPERATION operationGetByVal(ExecState* exec, EncodedJSValue encodedBase, EncodedJSValue encodedProperty)
{
    JSGlobalData* globalData = &exec->globalData();
    NativeCallFrameTracer tracer(globalData, exec);
    
    JSValue baseValue = JSValue::decode(encodedBase);
    JSValue property = JSValue::decode(encodedProperty);

    if (LIKELY(baseValue.isCell())) {
        JSCell* base = baseValue.asCell();

        if (property.isUInt32()) {
            return getByVal(exec, base, property.asUInt32());
        } else if (property.isDouble()) {
            double propertyAsDouble = property.asDouble();
            uint32_t propertyAsUInt32 = static_cast<uint32_t>(propertyAsDouble);
            if (propertyAsUInt32 == propertyAsDouble)
                return getByVal(exec, base, propertyAsUInt32);
        } else if (property.isString()) {
            if (JSValue result = base->fastGetOwnProperty(exec, asString(property)->value(exec)))
                return JSValue::encode(result);
        }
    }

    Identifier ident(exec, property.toString(exec)->value(exec));
    return JSValue::encode(baseValue.get(exec, ident));
}

EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(ExecState* exec)
{
    VM& vm = exec->vm();
    JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
    if (thisValue.isUndefinedOrNull())
        return JSValue::encode(thisValue.isUndefined() ? vm.smallStrings.undefinedObjectString() : vm.smallStrings.nullObjectString());
    JSObject* thisObject = thisValue.toObject(exec);

    JSValue stringTag = thisObject->get(exec, exec->propertyNames().toStringTagSymbol);
    if (stringTag.isString()) {
        JSRopeString::RopeBuilder<RecordOverflow> ropeBuilder(vm);
        ropeBuilder.append(vm.smallStrings.objectStringStart());
        ropeBuilder.append(jsCast<JSString*>(stringTag));
        ropeBuilder.append(vm.smallStrings.singleCharacterString(']'));
        if(ropeBuilder.hasOverflowed())
            return JSValue::encode(throwOutOfMemoryError(exec));

        return JSValue::encode(ropeBuilder.release());
    }

    JSString* result = thisObject->structure(vm)->objectToStringValue();
    if (!result) {
        RefPtr<StringImpl> newString = WTF::tryMakeString("[object ", thisObject->methodTable(exec->vm())->className(thisObject), "]");
        if (!newString)
            return JSValue::encode(throwOutOfMemoryError(exec));

        result = jsNontrivialString(&vm, newString.release());
        thisObject->structure(vm)->setObjectToStringValue(vm, result);
    }
    return JSValue::encode(result);
}

// ECMA 15.9.3
JSObject* constructDate(ExecState* exec, JSGlobalObject* globalObject, JSValue newTarget, const ArgList& args)
{
    VM& vm = exec->vm();
    int numArgs = args.size();

    double value;

    if (numArgs == 0) // new Date() ECMA 15.9.3.3
        value = NORMAL_OR_DETERMINISTIC_FUNCTION(jsCurrentTime(), deterministicCurrentTime(globalObject));
    else if (numArgs == 1) {
        if (args.at(0).inherits(DateInstance::info()))
            value = asDateInstance(args.at(0))->internalNumber();
        else {
            JSValue primitive = args.at(0).toPrimitive(exec);
            if (primitive.isString())
                value = parseDate(vm, primitive.getString(exec));
            else
                value = primitive.toNumber(exec);
        }
    } else
        value = millisecondsFromComponents(exec, args, WTF::LocalTime);

    Structure* dateStructure = InternalFunction::createSubclassStructure(exec, newTarget, globalObject->dateStructure());

    return DateInstance::create(vm, dateStructure, value);
}

static bool extractSourceInformationFromException(JSC::ExecState* exec, JSObject* exceptionObject, int* lineNumber, int* columnNumber, String* sourceURL)
{
    VM& vm = exec->vm();
    auto scope = DECLARE_CATCH_SCOPE(vm);

    // FIXME: <http://webkit.org/b/115087> Web Inspector: Should not need to evaluate JavaScript handling exceptions
    JSValue lineValue = exceptionObject->getDirect(vm, Identifier::fromString(exec, "line"));
    JSValue columnValue = exceptionObject->getDirect(vm, Identifier::fromString(exec, "column"));
    JSValue sourceURLValue = exceptionObject->getDirect(vm, Identifier::fromString(exec, "sourceURL"));
    
    bool result = false;
    if (lineValue && lineValue.isNumber()
        && sourceURLValue && sourceURLValue.isString()) {
        *lineNumber = int(lineValue.toNumber(exec));
        *columnNumber = columnValue && columnValue.isNumber() ? int(columnValue.toNumber(exec)) : 0;
        *sourceURL = sourceURLValue.toWTFString(exec);
        result = true;
    } else if (ErrorInstance* error = jsDynamicCast<ErrorInstance*>(vm, exceptionObject)) {
        unsigned unsignedLine;
        unsigned unsignedColumn;
        result = getLineColumnAndSource(error->stackTrace(), unsignedLine, unsignedColumn, *sourceURL);
        *lineNumber = static_cast<int>(unsignedLine);
        *columnNumber = static_cast<int>(unsignedColumn);
    }
    
    if (sourceURL->isEmpty())
        *sourceURL = "undefined"_s;
    
    scope.clearException();
    return result;
}

JSValue JSInjectedScriptHost::type(ExecState* exec)
{
    if (exec->argumentCount() < 1)
        return jsUndefined();

    JSValue value = exec->argument(0);
    if (value.isString())
        return jsString(exec, String("string"));
    if (value.inherits(&JSArray::s_info))
        return jsString(exec, String("array"));
    if (value.isBoolean())
        return jsString(exec, String("boolean"));
    if (value.isNumber())
        return jsString(exec, String("number"));
    if (value.inherits(&DateInstance::s_info))
        return jsString(exec, String("date"));
    if (value.inherits(&RegExpObject::s_info))
        return jsString(exec, String("regexp"));
    if (value.inherits(&JSNode::s_info))
        return jsString(exec, String("node"));
    if (value.inherits(&JSNodeList::s_info))
        return jsString(exec, String("array"));
    if (value.inherits(&JSHTMLCollection::s_info))
        return jsString(exec, String("array"));
    if (value.inherits(&JSInt8Array::s_info) || value.inherits(&JSInt16Array::s_info) || value.inherits(&JSInt32Array::s_info))
        return jsString(exec, String("array"));
    if (value.inherits(&JSUint8Array::s_info) || value.inherits(&JSUint16Array::s_info) || value.inherits(&JSUint32Array::s_info))
        return jsString(exec, String("array"));
    if (value.inherits(&JSFloat32Array::s_info) || value.inherits(&JSFloat64Array::s_info))
        return jsString(exec, String("array"));
    return jsUndefined();
}

JSValue jsTypeStringForValue(VM& vm, JSGlobalObject* globalObject, JSValue v)
{
    if (v.isUndefined())
        return vm.smallStrings.undefinedString();
    if (v.isBoolean())
        return vm.smallStrings.booleanString();
    if (v.isNumber())
        return vm.smallStrings.numberString();
    if (v.isString())
        return vm.smallStrings.stringString();
    if (v.isSymbol())
        return vm.smallStrings.symbolString();
    if (v.isObject()) {
        JSObject* object = asObject(v);
        // Return "undefined" for objects that should be treated
        // as null when doing comparisons.
        if (object->structure(vm)->masqueradesAsUndefined(globalObject))
            return vm.smallStrings.undefinedString();
        if (object->type() == JSFunctionType)
            return vm.smallStrings.functionString();
        if (object->inlineTypeFlags() & TypeOfShouldCallGetCallData) {
            CallData callData;
            JSObject* object = asObject(v);
            if (object->methodTable(vm)->getCallData(object, callData) != CallTypeNone)
                return vm.smallStrings.functionString();
        }
    }
    return vm.smallStrings.objectString();
}

static void populateContextMenuItems(ExecState* exec, JSArray* array, ContextMenu& menu)
{
    for (size_t i = 0; i < array->length(); ++i) {
        JSObject* item = asObject(array->getIndex(exec, i));
        JSValue label = item->get(exec, Identifier::fromString(exec, "label"));
        JSValue type = item->get(exec, Identifier::fromString(exec, "type"));
        JSValue id = item->get(exec, Identifier::fromString(exec, "id"));
        JSValue enabled = item->get(exec, Identifier::fromString(exec, "enabled"));
        JSValue checked = item->get(exec, Identifier::fromString(exec, "checked"));
        JSValue subItems = item->get(exec, Identifier::fromString(exec, "subItems"));
        if (!type.isString())
            continue;

        String typeString = type.toWTFString(exec);
        if (typeString == "separator") {
            ContextMenuItem item(SeparatorType, ContextMenuItemTagNoAction, String());
            menu.appendItem(item);
        } else if (typeString == "subMenu" && subItems.inherits(JSArray::info())) {
            ContextMenu subMenu;
            JSArray* subItemsArray = asArray(subItems);
            populateContextMenuItems(exec, subItemsArray, subMenu);
            ContextMenuItem item(SubmenuType, ContextMenuItemTagNoAction, label.toWTFString(exec), &subMenu);
            menu.appendItem(item);
        } else {
            ContextMenuAction typedId = static_cast<ContextMenuAction>(ContextMenuItemBaseCustomTag + id.toInt32(exec));
            ContextMenuItem menuItem((typeString == "checkbox" ? CheckableActionType : ActionType), typedId, label.toWTFString(exec));
            if (!enabled.isUndefined())
                menuItem.setEnabled(enabled.toBoolean(exec));
            if (!checked.isUndefined())
                menuItem.setChecked(checked.toBoolean(exec));
            menu.appendItem(menuItem);
        }
    }
}

JSValue JSInjectedScriptHost::subtype(ExecState* exec)
{
    if (exec->argumentCount() < 1)
        return jsUndefined();

    JSValue value = exec->uncheckedArgument(0);
    if (value.isString())
        return exec->vm().smallStrings.stringString();
    if (value.isBoolean())
        return exec->vm().smallStrings.booleanString();
    if (value.isNumber())
        return exec->vm().smallStrings.numberString();
    if (value.isSymbol())
        return exec->vm().smallStrings.symbolString();

    JSObject* object = asObject(value);
    if (object) {
        if (object->isErrorInstance())
            return jsNontrivialString(exec, ASCIILiteral("error"));

        // Consider class constructor functions class objects.
        JSFunction* function = jsDynamicCast<JSFunction*>(value);
        if (function && function->isClassConstructorFunction())
            return jsNontrivialString(exec, ASCIILiteral("class"));
    }

    if (value.inherits(JSArray::info()))
        return jsNontrivialString(exec, ASCIILiteral("array"));
    if (value.inherits(DirectArguments::info()) || value.inherits(ScopedArguments::info()))
        return jsNontrivialString(exec, ASCIILiteral("array"));

    if (value.inherits(DateInstance::info()))
        return jsNontrivialString(exec, ASCIILiteral("date"));
    if (value.inherits(RegExpObject::info()))
        return jsNontrivialString(exec, ASCIILiteral("regexp"));

    if (value.inherits(JSMap::info()))
        return jsNontrivialString(exec, ASCIILiteral("map"));
    if (value.inherits(JSSet::info()))
        return jsNontrivialString(exec, ASCIILiteral("set"));
    if (value.inherits(JSWeakMap::info()))
        return jsNontrivialString(exec, ASCIILiteral("weakmap"));
    if (value.inherits(JSWeakSet::info()))
        return jsNontrivialString(exec, ASCIILiteral("weakset"));

    if (value.inherits(JSArrayIterator::info())
        || value.inherits(JSMapIterator::info())
        || value.inherits(JSSetIterator::info())
        || value.inherits(JSStringIterator::info()))
        return jsNontrivialString(exec, ASCIILiteral("iterator"));

    if (value.inherits(JSInt8Array::info()) || value.inherits(JSInt16Array::info()) || value.inherits(JSInt32Array::info()))
        return jsNontrivialString(exec, ASCIILiteral("array"));
    if (value.inherits(JSUint8Array::info()) || value.inherits(JSUint16Array::info()) || value.inherits(JSUint32Array::info()))
        return jsNontrivialString(exec, ASCIILiteral("array"));
    if (value.inherits(JSFloat32Array::info()) || value.inherits(JSFloat64Array::info()))
        return jsNontrivialString(exec, ASCIILiteral("array"));

    return impl().subtype(exec, value);
}

EncodedJSValue JSC_HOST_CALL jsHTMLDocumentPrototypeFunctionWrite(ExecState* exec)
{
    JSValue thisValue = exec->hostThisValue();
    if (!thisValue.inherits(&JSHTMLDocument::s_info))
        return throwVMTypeError(exec);
    JSHTMLDocument* castedThis = static_cast<JSHTMLDocument*>(asObject(thisValue));
#ifdef JSC_TAINTED
/*
if we comment out the following code segement and move the detection to bindings/js/JSHTMLDocumentCustom.cpp
one of the test case like below cannot be detected anymore. need to investigate the reason behind.
document.write("hello"+document.location.href.substring(document.location.href.indexOf("default=")+8));\

the guess is the following code does not cover the primitive string.
*/
    JSValue s = exec->argument(0);
    if (s.isString() && s.isTainted()) {
        HTMLDocument* d1 = static_cast<HTMLDocument*>(castedThis->impl());
        d1->setTainted(s.isTainted());

	TaintedStructure trace_struct;
	trace_struct.taintedno = s.isTainted();
	trace_struct.internalfunc = "jsHTMLDocumentPrototypeFunctionWrite";
	trace_struct.jsfunc = "document.write";
	trace_struct.action = "sink";

	char msg[20];
	stringstream msgss;
	snprintf(msg, 20, "%s", s.toString(exec).utf8(true).data());
	msgss << msg;
	msgss >> trace_struct.value;

	TaintedTrace* trace = TaintedTrace::getInstance();
	trace->addTaintedTrace(trace_struct);
    }

PassRefPtr<ScriptCallStack> createScriptCallStackFromException(JSC::ExecState* exec, JSC::JSValue& exception, size_t maxStackSize)
{
    Vector<ScriptCallFrame> frames;
    RefCountedArray<StackFrame> stackTrace = exec->vm().exceptionStack();
    for (size_t i = 0; i < stackTrace.size() && i < maxStackSize; i++) {
        if (!stackTrace[i].callee && frames.size())
            break;

        String functionName = stackTrace[i].friendlyFunctionName(exec);
        unsigned line;
        unsigned column;
        stackTrace[i].computeLineAndColumn(line, column);
        frames.append(ScriptCallFrame(functionName, stackTrace[i].sourceURL, line, column));
    }

    // FIXME: <http://webkit.org/b/115087> Web Inspector: WebCore::reportException should not evaluate JavaScript handling exceptions
    // Fallback to getting at least the line and sourceURL from the exception if it has values and the exceptionStack doesn't.
    if (frames.size() > 0) {
        const ScriptCallFrame& firstCallFrame = frames.first();
        JSObject* exceptionObject = exception.toObject(exec);
        if (exception.isObject() && firstCallFrame.sourceURL().isEmpty()) {
            JSValue lineValue = exceptionObject->getDirect(exec->vm(), Identifier(exec, "line"));
            int lineNumber = lineValue && lineValue.isNumber() ? int(lineValue.toNumber(exec)) : 0;
            JSValue sourceURLValue = exceptionObject->getDirect(exec->vm(), Identifier(exec, "sourceURL"));
            String exceptionSourceURL = sourceURLValue && sourceURLValue.isString() ? sourceURLValue.toString(exec)->value(exec) : ASCIILiteral("undefined");
            frames[0] = ScriptCallFrame(firstCallFrame.functionName(), exceptionSourceURL, lineNumber, 0);
        }
    }

    return ScriptCallStack::create(frames);
}