C++ JSValue::asNumber方法代码示例

char* newTypedArrayWithOneArgument(
    ExecState* exec, Structure* structure, EncodedJSValue encodedValue)
{
    VM& vm = exec->vm();
    NativeCallFrameTracer tracer(&vm, exec);
    
    JSValue value = JSValue::decode(encodedValue);
    
    if (JSArrayBuffer* jsBuffer = jsDynamicCast<JSArrayBuffer*>(value)) {
        RefPtr<ArrayBuffer> buffer = jsBuffer->impl();
        
        if (buffer->byteLength() % ViewClass::elementSize) {
            vm.throwException(exec, createRangeError(exec, ASCIILiteral("ArrayBuffer length minus the byteOffset is not a multiple of the element size")));
            return 0;
        }
        return bitwise_cast<char*>(
            ViewClass::create(
                exec, structure, buffer, 0, buffer->byteLength() / ViewClass::elementSize));
    }
    
    if (JSObject* object = jsDynamicCast<JSObject*>(value)) {
        unsigned length = object->get(exec, vm.propertyNames->length).toUInt32(exec);
        if (exec->hadException())
            return 0;
        
        ViewClass* result = ViewClass::createUninitialized(exec, structure, length);
        if (!result)
            return 0;
        
        if (!result->set(exec, object, 0, length))
            return 0;
        
        return bitwise_cast<char*>(result);
    }
    
    int length;
    if (value.isInt32())
        length = value.asInt32();
    else if (!value.isNumber()) {
        vm.throwException(exec, createTypeError(exec, ASCIILiteral("Invalid array length argument")));
        return 0;
    } else {
        length = static_cast<int>(value.asNumber());
        if (length != value.asNumber()) {
            vm.throwException(exec, createTypeError(exec, ASCIILiteral("Invalid array length argument (fractional lengths not allowed)")));
            return 0;
        }
    }
    
    if (length < 0) {
        vm.throwException(exec, createRangeError(exec, ASCIILiteral("Requested length is negative")));
        return 0;
    }
    
    return bitwise_cast<char*>(ViewClass::create(exec, structure, length));
}

// See ES5.1 9.12
bool sameValue(ExecState* exec, JSValue a, JSValue b)
{
    if (!a.isNumber())
        return JSValue::strictEqual(exec, a, b);
    if (!b.isNumber())
        return false;
    double x = a.asNumber();
    double y = b.asNumber();
    if (isnan(x))
        return isnan(y);
    return bitwise_cast<uint64_t>(x) == bitwise_cast<uint64_t>(y);
}

SpeculatedType speculationFromValue(JSValue value)
{
    if (value.isEmpty())
        return SpecEmpty;
    if (value.isInt32())
        return SpecInt32;
    if (value.isDouble()) {
        double number = value.asNumber();
        if (number == number) {
            int64_t asInt64 = static_cast<int64_t>(number);
            if (asInt64 == number && (asInt64 || !std::signbit(number))
                && asInt64 < (static_cast<int64_t>(1) << 47)
                && asInt64 >= -(static_cast<int64_t>(1) << 47)) {
                return SpecInt48AsDouble;
            }
            return SpecNonIntAsDouble;
        }
        return SpecDoubleNaN;
    }
    if (value.isCell())
        return speculationFromCell(value.asCell());
    if (value.isBoolean())
        return SpecBoolean;
    ASSERT(value.isUndefinedOrNull());
    return SpecOther;
}

static void updateArithProfileForUnaryArithOp(Instruction* pc, JSValue result, JSValue operand)
{
    ArithProfile& profile = *bitwise_cast<ArithProfile*>(&pc[3].u.operand);
    profile.observeLHS(operand);
    ASSERT(result.isNumber());
    if (!result.isInt32()) {
        if (operand.isInt32())
            profile.setObservedInt32Overflow();

        double doubleVal = result.asNumber();
        if (!doubleVal && std::signbit(doubleVal))
            profile.setObservedNegZeroDouble();
        else {
            profile.setObservedNonNegZeroDouble();

            // The Int52 overflow check here intentionally omits 1ll << 51 as a valid negative Int52 value.
            // Therefore, we will get a false positive if the result is that value. This is intentionally
            // done to simplify the checking algorithm.
            static const int64_t int52OverflowPoint = (1ll << 51);
            int64_t int64Val = static_cast<int64_t>(std::abs(doubleVal));
            if (int64Val >= int52OverflowPoint)
                profile.setObservedInt52Overflow();
        }
    }
}

static inline UString gap(ExecState* exec, JSValue space)
{
    const unsigned maxGapLength = 10;
    space = unwrapBoxedPrimitive(exec, space);

    // If the space value is a number, create a gap string with that number of spaces.
    if (space.isNumber()) {
        double spaceCount = space.asNumber();
        int count;
        if (spaceCount > maxGapLength)
            count = maxGapLength;
        else if (!(spaceCount > 0))
            count = 0;
        else
            count = static_cast<int>(spaceCount);
        UChar spaces[maxGapLength];
        for (int i = 0; i < count; ++i)
            spaces[i] = ' ';
        return UString(spaces, count);
    }

    // If the space value is a string, use it as the gap string, otherwise use no gap string.
    UString spaces = space.getString(exec);
    if (spaces.length() > maxGapLength) {
        spaces = spaces.substringSharingImpl(0, maxGapLength);
    }
    return spaces;
}

static inline void putByVal(ExecState* exec, JSValue baseValue, uint32_t index, JSValue value)
{
    JSGlobalData* globalData = &exec->globalData();

    if (isJSArray(baseValue)) {
        JSArray* array = asArray(baseValue);
        if (array->canSetIndex(index)) {
            array->setIndex(*globalData, index, value);
            return;
        }

        JSArray::putByIndex(array, exec, index, value, strict);
        return;
    }

    if (isJSByteArray(baseValue) && asByteArray(baseValue)->canAccessIndex(index)) {
        JSByteArray* byteArray = asByteArray(baseValue);
        // FIXME: the JITstub used to relink this to an optimized form!
        if (value.isInt32()) {
            byteArray->setIndex(index, value.asInt32());
            return;
        }

        if (value.isNumber()) {
            byteArray->setIndex(index, value.asNumber());
            return;
        }
    }

    baseValue.putByIndex(exec, index, value, strict);
}

static void updateResultProfileForBinaryArithOp(ExecState* exec, Instruction* pc, JSValue result, JSValue left, JSValue right)
{
    CodeBlock* codeBlock = exec->codeBlock();
    unsigned bytecodeOffset = codeBlock->bytecodeOffset(pc);
    ResultProfile* profile = codeBlock->ensureResultProfile(bytecodeOffset);

    if (result.isNumber()) {
        if (!result.isInt32()) {
            if (left.isInt32() && right.isInt32())
                profile->setObservedInt32Overflow();

            double doubleVal = result.asNumber();
            if (!doubleVal && std::signbit(doubleVal))
                profile->setObservedNegZeroDouble();
            else {
                profile->setObservedNonNegZeroDouble();

                // The Int52 overflow check here intentionally omits 1ll << 51 as a valid negative Int52 value.
                // Therefore, we will get a false positive if the result is that value. This is intentionally
                // done to simplify the checking algorithm.
                static const int64_t int52OverflowPoint = (1ll << 51);
                int64_t int64Val = static_cast<int64_t>(std::abs(doubleVal));
                if (int64Val >= int52OverflowPoint)
                    profile->setObservedInt52Overflow();
            }
        }
    } else
        profile->setObservedNonNumber();
}

 bool isWithinPowerOfTwoForConstant(Node* node)
 {
     JSValue immediateValue = node->asJSValue();
     if (!immediateValue.isNumber())
         return false;
     double immediate = immediateValue.asNumber();
     return immediate > -(static_cast<int64_t>(1) << power) && immediate < (static_cast<int64_t>(1) << power);
 }

double valueToDate(ExecState* exec, JSValue value)
{
    if (value.isNumber())
        return value.asNumber();
    if (!value.inherits(DateInstance::info()))
        return std::numeric_limits<double>::quiet_NaN();
    return static_cast<DateInstance*>(value.toObject(exec))->internalNumber();
}

static RefPtr<InspectorValue> jsToInspectorValue(ExecState* scriptState, JSValue value, int maxDepth)
{
    if (!value) {
        ASSERT_NOT_REACHED();
        return nullptr;
    }

    if (!maxDepth)
        return nullptr;

    maxDepth--;

    if (value.isNull() || value.isUndefined())
        return InspectorValue::null();
    if (value.isBoolean())
        return InspectorValue::create(value.asBoolean());
    if (value.isNumber() && value.isDouble())
        return InspectorValue::create(value.asNumber());
    if (value.isNumber() && value.isMachineInt())
        return InspectorValue::create(static_cast<int>(value.asMachineInt()));
    if (value.isString())
        return InspectorValue::create(value.getString(scriptState));

    if (value.isObject()) {
        if (isJSArray(value)) {
            Ref<InspectorArray> inspectorArray = InspectorArray::create();
            JSArray* array = asArray(value);
            unsigned length = array->length();
            for (unsigned i = 0; i < length; i++) {
                JSValue element = array->getIndex(scriptState, i);
                RefPtr<InspectorValue> elementValue = jsToInspectorValue(scriptState, element, maxDepth);
                if (!elementValue)
                    return nullptr;
                inspectorArray->pushValue(WTFMove(elementValue));
            }
            return WTFMove(inspectorArray);
        }
        Ref<InspectorObject> inspectorObject = InspectorObject::create();
        JSObject* object = value.getObject();
        PropertyNameArray propertyNames(scriptState, PropertyNameMode::Strings);
        object->methodTable()->getOwnPropertyNames(object, scriptState, propertyNames, EnumerationMode());
        for (size_t i = 0; i < propertyNames.size(); i++) {
            const Identifier& name = propertyNames[i];
            JSValue propertyValue = object->get(scriptState, name);
            RefPtr<InspectorValue> inspectorValue = jsToInspectorValue(scriptState, propertyValue, maxDepth);
            if (!inspectorValue)
                return nullptr;
            inspectorObject->setValue(name.string(), WTFMove(inspectorValue));
        }
        return WTFMove(inspectorObject);
    }

    ASSERT_NOT_REACHED();
    return nullptr;
}

static PassRefPtr<InspectorValue> jsToInspectorValue(ScriptState* scriptState, JSValue value, int maxDepth)
{
    if (!value) {
        ASSERT_NOT_REACHED();
        return 0;
    }

    if (!maxDepth)
        return 0;
    maxDepth--;

    if (value.isNull() || value.isUndefined())
        return InspectorValue::null();
    if (value.isBoolean())
        return InspectorBasicValue::create(value.asBoolean());
    if (value.isNumber())
        return InspectorBasicValue::create(value.asNumber());
    if (value.isString()) {
        String s = value.getString(scriptState);
        return InspectorString::create(String(s.characters(), s.length()));
    }
    if (value.isObject()) {
        if (isJSArray(value)) {
            RefPtr<InspectorArray> inspectorArray = InspectorArray::create();
            JSArray* array = asArray(value);
            unsigned length = array->length();
            for (unsigned i = 0; i < length; i++) {
                // FIXME: What if the array is in sparse mode? https://bugs.webkit.org/show_bug.cgi?id=95610
                JSValue element = array->getIndexQuickly(i);
                RefPtr<InspectorValue> elementValue = jsToInspectorValue(scriptState, element, maxDepth);
                if (!elementValue)
                    return 0;
                inspectorArray->pushValue(elementValue);
            }
            return inspectorArray;
        }
        RefPtr<InspectorObject> inspectorObject = InspectorObject::create();
        JSObject* object = value.getObject();
        PropertyNameArray propertyNames(scriptState);
        object->methodTable()->getOwnPropertyNames(object, scriptState, propertyNames, ExcludeDontEnumProperties);
        for (size_t i = 0; i < propertyNames.size(); i++) {
            const Identifier& name =  propertyNames[i];
            JSValue propertyValue = object->get(scriptState, name);
            RefPtr<InspectorValue> inspectorValue = jsToInspectorValue(scriptState, propertyValue, maxDepth);
            if (!inspectorValue)
                return 0;
            inspectorObject->setValue(String(name.characters(), name.length()), inspectorValue);
        }
        return inspectorObject;
    }
    ASSERT_NOT_REACHED();
    return 0;
}

// 15.3.4.5 Function.prototype.bind (thisArg [, arg1 [, arg2, ...]])
EncodedJSValue JSC_HOST_CALL functionProtoFuncBind(ExecState* exec)
{
    VM& vm = exec->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);
    JSGlobalObject* globalObject = exec->callee()->globalObject();

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

    // If IsCallable(Target) is false, throw a TypeError exception.
    CallData callData;
    CallType callType = getCallData(target, callData);
    if (callType == CallType::None)
        return throwVMTypeError(exec, scope);
    // Primitive values are not callable.
    ASSERT(target.isObject());
    JSObject* targetObject = asObject(target);

    // Let A be a new (possibly empty) internal list of all of the argument values provided after thisArg (arg1, arg2 etc), in order.
    size_t numBoundArgs = exec->argumentCount() > 1 ? exec->argumentCount() - 1 : 0;
    JSArray* boundArgs;
    if (numBoundArgs) {
        boundArgs = JSArray::tryCreateUninitialized(vm, globalObject->arrayStructureForIndexingTypeDuringAllocation(ArrayWithContiguous), numBoundArgs);
        if (!boundArgs)
            return JSValue::encode(throwOutOfMemoryError(exec, scope));
        
        for (size_t i = 0; i < numBoundArgs; ++i)
            boundArgs->initializeIndex(vm, i, exec->argument(i + 1));
    } else
        boundArgs = nullptr;

    // If the [[Class]] internal property of Target is "Function", then ...
    // Else set the length own property of F to 0.
    unsigned length = 0;
    if (targetObject->hasOwnProperty(exec, exec->propertyNames().length)) {
        if (exec->hadException())
            return JSValue::encode(jsUndefined());

        // a. Let L be the length property of Target minus the length of A.
        // b. Set the length own property of F to either 0 or L, whichever is larger.
        JSValue lengthValue = target.get(exec, exec->propertyNames().length);
        if (lengthValue.isNumber()) {
            unsigned targetLength = (unsigned)lengthValue.asNumber();
            if (targetLength > numBoundArgs)
                length = targetLength - numBoundArgs;
        }
    }

    JSValue nameProp = target.get(exec, exec->propertyNames().name);
    JSString* name = nameProp.isString() ? nameProp.toString(exec) : jsEmptyString(exec);
    return JSValue::encode(JSBoundFunction::create(vm, exec, globalObject, targetObject, exec->argument(0), boundArgs, length, name->value(exec)));
}

PredictedType predictionFromValue(JSValue value)
{
    if (value.isInt32())
        return PredictInt32;
    if (value.isDouble()) {
        double number = value.asNumber();
        if (number == number)
            return PredictDoubleReal;
        return PredictDoubleNaN;
    }
    if (value.isCell())
        return predictionFromCell(value.asCell());
    if (value.isBoolean())
        return PredictBoolean;
    ASSERT(value.isUndefinedOrNull());
    return PredictOther;
}

SpeculatedType speculationFromValue(JSValue value)
{
    if (value.isEmpty())
        return SpecEmpty;
    if (value.isInt32())
        return SpecInt32;
    if (value.isDouble()) {
        double number = value.asNumber();
        if (number != number)
            return SpecDoubleNaN;
        if (value.isMachineInt())
            return SpecInt52AsDouble;
        return SpecNonIntAsDouble;
    }
    if (value.isCell())
        return speculationFromCell(value.asCell());
    if (value.isBoolean())
        return SpecBoolean;
    ASSERT(value.isUndefinedOrNull());
    return SpecOther;
}

jvalue convertValueToJValue(ExecState* exec, RootObject* rootObject, JSValue value, JavaType javaType, const char* javaClassName)
{
    JSLock lock(SilenceAssertionsOnly);

    jvalue result;
    memset(&result, 0, sizeof(jvalue));

    switch (javaType) {
    case JavaTypeArray:
    case JavaTypeObject:
        {
            // FIXME: JavaJSObject::convertValueToJObject functionality is almost exactly the same,
            // these functions should use common code.

            if (value.isObject()) {
                JSObject* object = asObject(value);
                if (object->inherits(&JavaRuntimeObject::s_info)) {
                    // Unwrap a Java instance.
                    JavaRuntimeObject* runtimeObject = static_cast<JavaRuntimeObject*>(object);
                    JavaInstance* instance = runtimeObject->getInternalJavaInstance();
                    if (instance)
                        result.l = instance->javaInstance();
                } else if (object->classInfo() == &RuntimeArray::s_info) {
                    // Input is a JavaScript Array that was originally created from a Java Array
                    RuntimeArray* imp = static_cast<RuntimeArray*>(object);
                    JavaArray* array = static_cast<JavaArray*>(imp->getConcreteArray());
                    result.l = array->javaArray();
                } else if (object->classInfo() == &JSArray::s_info) {
                    // Input is a Javascript Array. We need to create it to a Java Array.
                    result.l = convertArrayInstanceToJavaArray(exec, asArray(value), javaClassName);
                } else if ((!result.l && (!strcmp(javaClassName, "java.lang.Object")))
                           || (!strcmp(javaClassName, "netscape.javascript.JSObject"))) {
                    // Wrap objects in JSObject instances.
                    JNIEnv* env = getJNIEnv();
                    jclass jsObjectClass = env->FindClass("sun/plugin/javascript/webkit/JSObject");
                    jmethodID constructorID = env->GetMethodID(jsObjectClass, "<init>", "(J)V");
                    if (constructorID) {
                        jlong nativeHandle = ptr_to_jlong(object);
                        rootObject->gcProtect(object);
                        result.l = env->NewObject(jsObjectClass, constructorID, nativeHandle);
                    }
                }
            }

            // Create an appropriate Java object if target type is java.lang.Object.
            if (!result.l && !strcmp(javaClassName, "java.lang.Object")) {
                if (value.isString()) {
                    UString stringValue = asString(value)->value(exec);
                    JNIEnv* env = getJNIEnv();
                    jobject javaString = env->functions->NewString(env, (const jchar*)stringValue.characters(), stringValue.length());
                    result.l = javaString;
                } else if (value.isNumber()) {
                    double doubleValue = value.asNumber();
                    JNIEnv* env = getJNIEnv();
                    jclass clazz = env->FindClass("java/lang/Double");
                    jmethodID constructor = env->GetMethodID(clazz, "<init>", "(D)V");
                    jobject javaDouble = env->functions->NewObject(env, clazz, constructor, doubleValue);
                    result.l = javaDouble;
                } else if (value.isBoolean()) {
                    bool boolValue = value.asBoolean();
                    JNIEnv* env = getJNIEnv();
                    jclass clazz = env->FindClass("java/lang/Boolean");
                    jmethodID constructor = env->GetMethodID(clazz, "<init>", "(Z)V");
                    jobject javaBoolean = env->functions->NewObject(env, clazz, constructor, boolValue);
                    result.l = javaBoolean;
                } else if (value.isUndefined()) {
                    UString stringValue = "undefined";
                    JNIEnv* env = getJNIEnv();
                    jobject javaString = env->functions->NewString(env, (const jchar*)stringValue.characters(), stringValue.length());
                    result.l = javaString;
                }
            }

            // Convert value to a string if the target type is a java.lang.String, and we're not
            // converting from a null.
            if (!result.l && !strcmp(javaClassName, "java.lang.String")) {
                if (!value.isNull()) {
                    UString stringValue = value.toString(exec);
                    JNIEnv* env = getJNIEnv();
                    jobject javaString = env->functions->NewString(env, (const jchar*)stringValue.characters(), stringValue.length());
                    result.l = javaString;
                }
            }
        }
        break;

    case JavaTypeBoolean:
        {
            result.z = (jboolean)value.toNumber(exec);
        }
        break;

    case JavaTypeByte:
        {
            result.b = (jbyte)value.toNumber(exec);
        }
        break;

    case JavaTypeChar:
        {
//.........这里部分代码省略.........