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// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant
#include <QtQml/qjsmanagedvalue.h>
#include <QtQml/qjsengine.h>
#include <QtQml/private/qv4persistent_p.h>
#include <QtQml/private/qv4engine_p.h>
#include <QtQml/private/qv4mm_p.h>
#include <QtQml/private/qjsvalue_p.h>
#include <QtQml/private/qv4runtime_p.h>
#include <QtQml/private/qv4functionobject_p.h>
#include <QtQml/private/qv4jscall_p.h>
#include <QtQml/private/qv4urlobject_p.h>
#include <QtQml/private/qv4variantobject_p.h>
#include <QtQml/private/qv4qobjectwrapper_p.h>
#include <QtQml/private/qv4qmetaobjectwrapper_p.h>
#include <QtQml/private/qv4regexpobject_p.h>
#include <QtQml/private/qv4dateobject_p.h>
#include <QtQml/private/qv4errorobject_p.h>
#include <QtQml/private/qv4identifiertable_p.h>
#include <QtCore/qregularexpression.h>
#include <QtCore/qurl.h>
#include <QtCore/qdatetime.h>
QT_BEGIN_NAMESPACE
/*!
* \class QJSManagedValue
* \inmodule QtQml
* \since 6.1
*
* \inmodule QtQml
*
* \brief QJSManagedValue represents a value on the JavaScript heap belonging to a QJSEngine.
*
* The QJSManagedValue class allows interaction with JavaScript values in most
* ways you can interact with them from JavaScript itself. You can get and set
* properties and prototypes, and you can access arrays. Additionally, you can
* transform the value into the Qt counterparts of JavaScript objects. For
* example, a Url object may be transformed into a QUrl.
*
* A QJSManagedValue is always bound to a particular QJSEngine. You cannot use
* it independently. This means that you cannot have a QJSManagedValue from one
* engine be a property or a proptotype of a QJSManagedValue from a different
* engine.
*
* In contrast to QJSValue, almost all values held by QJSManagedValue live on
* the JavaScript heap. There is no inline or unmanaged storage. Therefore, you
* can get the prototype of a primitive value, and you can get the \c length
* property of a string.
*
* Only default-constructed or moved-from QJSManagedValues do not hold a value
* on the JavaScript heap. They represent \c undefined, which doesn't have any
* properties or prototypes.
*
* Also in contrast to QJSValue, QJSManagedValue does not catch any JavaScript
* exceptions. If an operation on a QJSManagedValue causes an error, it will
* generally return an \c undefined value and QJSEngine::hasError() will return
* \c true afterwards. You can then catch the exception using
* QJSEngine::catchError(), or pass it up the stack, at your own discretion.
*
* \note As the reference to the value on the JavaScript heap has to be freed
* on destruction, you cannot move a QJSManagedValue to a different thread.
* The destruction would take place in the new thread, which would create a race
* condition with the garbage collector on the original thread. This also means
* that you cannot hold a QJSManagedValue beyond the lifespan of its engine.
*
* The recommended way of working with a QJSManagedValue is creating it
* on the stack, possibly by moving a QJSValue and adding an engine, then
* performing the necessary operations on it, and finally moving it back into a
* QJSValue for storage. Moving between QJSManagedValue and QJSValue is fast.
*/
/*!
* \enum QJSManagedValue::Type
*
* This enum represents the JavaScript native types, as specified by
* \l{ECMA-262}.
*
* \value Undefined The \c undefined type
* \value Boolean The \c boolean type
* \value Number The \c number type
* \value String The \c string type
* \value Object The \c object type
* \value Symbol The \c symbol type
* \value Function The \c function type
*
* Note that the \c null value is not a type of itself but rather a special kind
* of object. You can query a QJSManagedValue for this condition using the
* isNull() method. Furthermore, JavaScript has no integer type, but it knows a
* special treatment of numbers in preparation for integer only operations. You
* can query a QJSManagedValue to find out whether it holds the result of such a
* treatment by using the isInteger() method.
*/
/*!
* \fn QJSManagedValue::QJSManagedValue()
*
* Creates a QJSManagedValue that represents the JavaScript \c undefined value.
* This is the only value not stored on the JavaScript heap. Calling engine()
* on a default-constructed QJSManagedValue will return nullptr.
*/
static QV4::ExecutionEngine *v4Engine(QV4::Value *d)
{
if (!d)
return nullptr;
QV4::ExecutionEngine *v4 = QV4::PersistentValueStorage::getEngine(d);
Q_ASSERT(v4);
return v4;
}
/*!
* Creates a QJSManagedValue from \a value, using the heap of \a engine. If
* \a value is itself managed and the engine it belongs to is not \a engine,
* the result is an \c undefined value, and a warning is generated.
*/
QJSManagedValue::QJSManagedValue(QJSValue value, QJSEngine *engine)
{
QV4::ExecutionEngine *v4 = engine->handle();
if (QV4::Value *m = QJSValuePrivate::takeManagedValue(&value)) {
if (Q_UNLIKELY(v4Engine(m) != v4)) {
qWarning("QJSManagedValue(QJSValue, QJSEngine *) failed: "
"Value was created in different engine.");
QV4::PersistentValueStorage::free(m);
return;
}
d = m;
return;
}
d = v4->memoryManager->m_persistentValues->allocate();
if (const QString *string = QJSValuePrivate::asQString(&value))
*d = v4->newString(*string);
else
*d = QJSValuePrivate::asReturnedValue(&value);
}
/*!
* Creates a QJSManagedValue from \a value using the heap of \a engine.
*/
QJSManagedValue::QJSManagedValue(const QJSPrimitiveValue &value, QJSEngine *engine) :
QJSManagedValue(engine->handle())
{
switch (value.type()) {
case QJSPrimitiveValue::Undefined:
*d = QV4::Encode::undefined();
return;
case QJSPrimitiveValue::Null:
*d = QV4::Encode::null();
return;
case QJSPrimitiveValue::Boolean:
*d = QV4::Encode(value.asBoolean());
return;
case QJSPrimitiveValue::Integer:
*d = QV4::Encode(value.asInteger());
return;
case QJSPrimitiveValue::Double:
*d = QV4::Encode(value.asDouble());
return;
case QJSPrimitiveValue::String:
*d = engine->handle()->newString(value.asString());
return;
}
Q_UNREACHABLE();
}
/*!
* Creates a QJSManagedValue from \a variant using the heap of \a engine.
*/
QJSManagedValue::QJSManagedValue(const QVariant &variant, QJSEngine *engine) :
QJSManagedValue(engine->handle())
{
*d = engine->handle()->fromVariant(variant);
}
/*!
* Creates a QJSManagedValue from \a string using the heap of \a engine.
*/
QJSManagedValue::QJSManagedValue(const QString &string, QJSEngine *engine) :
QJSManagedValue(engine->handle())
{
*d = engine->handle()->newString(string);
}
/*!
* Destroys the QJSManagedValue.
*
* \note This frees the memory slot it holds on the JavaScript heap. You must
* not destroy a QJSManagedValue from a different thread than the one
* where the QJSEngine it belongs to lives.
*/
QJSManagedValue::~QJSManagedValue()
{
QV4::PersistentValueStorage::free(d);
}
/*!
* Move-constructs a QJSManagedValue from \a other. This leaves \a other in
* the default-constructed state where it represents undefined and does not
* belong to any engine.
*/
QJSManagedValue::QJSManagedValue(QJSManagedValue &&other)
{
qSwap(d, other.d);
}
/*!
* Move-assigns a QJSManagedValue from \a other. This leaves \a other in
* the default-constructed state where it represents undefined and does not
* belong to any engine.
*
* \note This frees the memory slot this QJSManagedValue holds on the
* JavaScript heap. You must not move-assign a QJSManagedValue on a
* different thread than the one where the QJSEngine it belongs to lives.
*/
QJSManagedValue &QJSManagedValue::operator=(QJSManagedValue &&other)
{
if (this != &other) {
QV4::PersistentValueStorage::free(d);
d = nullptr;
qSwap(d, other.d);
}
return *this;
}
/*!
* Invokes the JavaScript '==' operator on this QJSManagedValue and \a other,
* and returns the result.
*
* \sa strictlyEquals
*/
bool QJSManagedValue::equals(const QJSManagedValue &other) const
{
if (!d)
return !other.d || other.d->isNullOrUndefined();
if (!other.d)
return d->isNullOrUndefined();
return QV4::Runtime::CompareEqual::call(*d, *other.d);
}
/*!
* Invokes the JavaScript '===' operator on this QJSManagedValue and \a other,
* and returns the result.
*
* \sa equals
*/
bool QJSManagedValue::strictlyEquals(const QJSManagedValue &other) const
{
if (!d)
return !other.d || other.d->isUndefined();
if (!other.d)
return d->isUndefined();
return QV4::RuntimeHelpers::strictEqual(*d, *other.d);
}
/*!
* Returns the QJSEngine this QJSManagedValue belongs to. Mind that the engine
* is always valid, unless the QJSManagedValue is default-constructed or moved
* from. In the latter case a nullptr is returned.
*/
QJSEngine *QJSManagedValue::engine() const
{
if (!d)
return nullptr;
if (QV4::ExecutionEngine *v4 = QV4::PersistentValueStorage::getEngine(d))
return v4->jsEngine();
return nullptr;
}
/*!
* Returns the prototype for this QJSManagedValue. This works on any value. You
* can, for example retrieve the JavaScript \c boolean prototype from a \c boolean
* value.
*/
QJSManagedValue QJSManagedValue::prototype() const
{
if (!d)
return QJSManagedValue();
QV4::ExecutionEngine *v4 = v4Engine(d);
QJSManagedValue result(v4);
if (auto object = d->as<QV4::Object>())
*result.d = object->getPrototypeOf();
else if (auto managed = d->as<QV4::Managed>())
*result.d = managed->internalClass()->prototype;
else if (d->isBoolean())
*result.d = v4->booleanPrototype();
else if (d->isNumber())
*result.d = v4->numberPrototype();
// If the prototype appears to be undefined, then it's actually null in JS terms.
if (result.d->isUndefined())
*result.d = QV4::Encode::null();
return result;
}
/*!
* Sets the prototype of this QJSManagedValue to \a prototype. A precondition
* is that \a prototype belongs to the same QJSEngine as this QJSManagedValue
* and is an object (including null). Furthermore, this QJSManagedValue has to
* be an object (excluding null), too, and you cannot create prototype cycles.
*/
void QJSManagedValue::setPrototype(const QJSManagedValue &prototype)
{
auto object = d ? d->as<QV4::Object>() : nullptr;
if (!object) {
qWarning("QJSManagedValue::setPrototype() failed: "
"Can only set a prototype on an object (excluding null).");
return;
}
// Object includes null ...
if (prototype.type() != QJSManagedValue::Object) {
qWarning("QJSManagedValue::setPrototype() failed: "
"Can only set objects (including null) as prototypes.");
return;
}
if (Q_UNLIKELY(object->engine() != v4Engine(prototype.d))) {
qWarning("QJSManagedValue::setPrototype() failed: "
"Prototype was created in differen engine.");
return;
}
// ... Null becomes nullptr here. That is why it appears as undefined later.
if (!object->setPrototypeOf(prototype.d->as<QV4::Object>())) {
qWarning("QJSManagedValue::setPrototype() failed: "
"Prototype cycle detected.");
}
}
/*!
* Returns the JavaScript type of this QJSManagedValue.
*/
QJSManagedValue::Type QJSManagedValue::type() const
{
if (!d || d->isUndefined())
return Undefined;
if (d->isBoolean())
return Boolean;
if (d->isNumber())
return Number;
if (d->isString())
return String;
if (d->isSymbol())
return Symbol;
if (d->isFunctionObject())
return Function;
return Object;
}
/*!
* \fn QJSManagedValue::isUndefined() const
*
* Returns \c true if the type of this QJSManagedValue is \c undefined,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isBoolean() const
*
* Returns \c true if the type of this QJSManagedValue is \c boolean,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isNumber() const
*
* Returns \c true if the type of this QJSManagedValue is \c number,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isString() const
*
* Returns \c true if the type of this QJSManagedValue is \c string,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isSymbol() const
*
* Returns \c true if the type of this QJSManagedValue is \c symbol,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isObject() const
*
* Returns \c true if the type of this QJSManagedValue is \c object,
* or \c false otherwise.
*/
/*!
* \fn QJSManagedValue::isFunction() const
*
* Returns \c true if the type of this QJSManagedValue is \c function,
* \c false otherwise.
*/
/*!
* Returns \c true if this QJSManagedValue holds the JavaScript \c null value,
* or \c false otherwise.
*/
bool QJSManagedValue::isNull() const
{
return d && d->isNull();
}
/*!
* Returns \c true if this QJSManagedValue holds an integer value, or \c false
* otherwise. The storage format of a number does not affect the result of any
* operations performed on it, but if an integer is stored, many operations are
* faster.
*/
bool QJSManagedValue::isInteger() const
{
return d && d->isInteger();
}
/*!
* Returns \c true if this value represents a JavaScript regular expression
* object, or \c false otherwise.
*/
bool QJSManagedValue::isRegularExpression() const
{
return d && d->as<QV4::RegExpObject>();
}
/*!
* Returns \c true if this value represents a JavaScript Array
* object, or \c false otherwise.
*/
bool QJSManagedValue::isArray() const
{
return d && d->as<QV4::ArrayObject>();
}
/*!
* Returns \c true if this value represents a JavaScript Url
* object, or \c false otherwise.
*/
bool QJSManagedValue::isUrl() const
{
return d && d->as<QV4::UrlObject>();
}
/*!
* Returns \c true if this value represents a QVariant managed on the JavaScript
* heap, or \c false otherwise.
*/
bool QJSManagedValue::isVariant() const
{
return d && d->as<QV4::VariantObject>();
}
/*!
* Returns \c true if this value represents a QObject pointer managed on the
* JavaScript heap, or \c false otherwise.
*/
bool QJSManagedValue::isQObject() const
{
return d && d->as<QV4::QObjectWrapper>();
}
/*!
* Returns \c true if this value represents a QMetaObject pointer managed on the
* JavaScript heap, or \c false otherwise.
*/
bool QJSManagedValue::isQMetaObject() const
{
return d && d->as<QV4::QMetaObjectWrapper>();
}
/*!
* Returns \c true if this value represents a JavaScript Date object, or
* \c false otherwise.
*/
bool QJSManagedValue::isDate() const
{
return d && d->as<QV4::DateObject>();
}
/*!
* Returns \c true if this value represents a JavaScript Error object, or
* \c false otherwise.
*/
bool QJSManagedValue::isError() const
{
return d && d->as<QV4::ErrorObject>();
}
/*!
* \internal
*
* Returns \c true if this value represents a JavaScript meta type, or \c false
* otherwise.
*/
bool QJSManagedValue::isJsMetaType() const
{
return d && d->as<QV4::InternalClass>();
}
/*!
* Converts the manged value to a string. If the managed value holds a string,
* that one is returned. Otherwise a string coercion by JavaScript rules is
* performed.
*
* \note Conversion of a managed value to a string can throw an exception. In
* particular, symbols cannot be coerced into strings, or a custom
* toString() method may throw. In this case the result is an empty
* string and the engine carries an error after the conversion.
*/
QString QJSManagedValue::toString() const
{
return d ? d->toQString() : QStringLiteral("undefined");
}
/*!
* Converts the manged value to a number. If the managed value holds a number,
* that one is returned. Otherwise a number coercion by JavaScript rules is
* performed.
*
* \note Conversion of a managed value to a number can throw an exception. In
* particular, symbols cannot be coerced into numbers, or a custom
* valueOf() method may throw. In this case the result is 0 and the
* engine carries an error after the conversion.
*/
double QJSManagedValue::toNumber() const
{
return d ? d->toNumber() : 0;
}
/*!
* Converts the manged value to a boolean. If the managed value holds a boolean,
* that one is returned. Otherwise a boolean coercion by JavaScript rules is
* performed.
*/
bool QJSManagedValue::toBoolean() const
{
return d ? d->toBoolean() : false;
}
/*!
* Converts the manged value to an integer. This first converts the value to a
* number by the rules of toNumber(), and then clamps it into the integer range
* by the rules given for coercing the arguments to JavaScript bit shift
* operators into 32bit integers.
*
* Internally, the value may already be stored as an integer, in which case a
* fast path is taken.
*
* \note Conversion of a managed value to a number can throw an exception. In
* particular, symbols cannot be coerced into numbers, or a custom
* valueOf() method may throw. In this case the result is 0 and the
* engine carries an error after the conversion.
*
* \note The JavaScript rules for coercing numbers into 32bit integers are
* unintuitive.
*/
int QJSManagedValue::toInteger() const
{
return d ? d->toInt32() : 0;
}
/*!
* Converts the manged value to a QJSPrimitiveValue. If the managed value holds
* a type supported by QJSPrimitiveValue, the value is copied. Otherwise the
* value is converted to a string, and the string is stored in
* QJSPrimitiveValue.
*
* \note Conversion of a managed value to a string can throw an exception. In
* particular, symbols cannot be coerced into strings, or a custom
* toString() method may throw. In this case the result is the undefined
* value and the engine carries an error after the conversion.
*/
QJSPrimitiveValue QJSManagedValue::toPrimitive() const
{
if (!d || d->isUndefined())
return QJSPrimitiveUndefined();
if (d->isNull())
return QJSPrimitiveNull();
if (d->isBoolean())
return d->booleanValue();
if (d->isInteger())
return d->integerValue();
if (d->isNumber())
return d->doubleValue();
bool ok;
const QString result = d->toQString(&ok);
return ok ? QJSPrimitiveValue(result) : QJSPrimitiveValue(QJSPrimitiveUndefined());
}
/*!
* Copies this QJSManagedValue into a new QJSValue. This is less efficient than
* move-constructing a QJSValue from a QJSManagedValue, but retains the
* QJSManagedValue.
*/
QJSValue QJSManagedValue::toJSValue() const
{
return d ? QJSValuePrivate::fromReturnedValue(d->asReturnedValue()) : QJSValue();
}
/*!
* Copies this QJSManagedValue into a new QVariant. This also creates a useful
* QVariant if QJSManagedValue::isVariant() returns false. QVariant can hold all
* types supported by QJSManagedValue.
*/
QVariant QJSManagedValue::toVariant() const
{
if (!d || d->isUndefined())
return QVariant();
if (d->isNull())
return QVariant(QMetaType::fromType<std::nullptr_t>(), nullptr);
if (d->isBoolean())
return QVariant(d->booleanValue());
if (d->isInteger())
return QVariant(d->integerValue());
if (d->isNumber())
return QVariant(d->doubleValue());
if (d->isString())
return QVariant(d->toQString());
if (d->as<QV4::Managed>())
return QV4::ExecutionEngine::toVariant(*d, QMetaType{}, true);
Q_UNREACHABLE_RETURN(QVariant());
}
/*!
* If this QJSManagedValue holds a JavaScript regular expression object, returns
* an equivalent QRegularExpression. Otherwise returns an invalid one.
*/
QRegularExpression QJSManagedValue::toRegularExpression() const
{
if (const auto *r = d ? d->as<QV4::RegExpObject>() : nullptr)
return r->toQRegularExpression();
return {};
}
/*!
* If this QJSManagedValue holds a JavaScript Url object, returns
* an equivalent QUrl. Otherwise returns an invalid one.
*/
QUrl QJSManagedValue::toUrl() const
{
if (const auto *u = d ? d->as<QV4::UrlObject>() : nullptr)
return u->toQUrl();
return {};
}
/*!
* If this QJSManagedValue holds a QObject pointer, returns it. Otherwise
* returns nullptr.
*/
QObject *QJSManagedValue::toQObject() const
{
if (const auto *o = d ? d->as<QV4::QObjectWrapper>() : nullptr)
return o->object();
return {};
}
/*!
* If this QJSManagedValue holds a QMetaObject pointer, returns it.
* Otherwise returns nullptr.
*/
const QMetaObject *QJSManagedValue::toQMetaObject() const
{
if (const auto *m = d ? d->as<QV4::QMetaObjectWrapper>() : nullptr)
return m->metaObject();
return {};
}
/*!
* If this QJSManagedValue holds a JavaScript Date object, returns an equivalent
* QDateTime. Otherwise returns an invalid one.
*/
QDateTime QJSManagedValue::toDateTime() const
{
if (const auto *t = d ? d->as<QV4::DateObject>() : nullptr)
return t->toQDateTime();
return {};
}
/*!
* Returns \c true if this QJSManagedValue has a property \a name, otherwise
* returns \c false. The properties of the prototype chain are considered.
*/
bool QJSManagedValue::hasProperty(const QString &name) const
{
if (!d || d->isNullOrUndefined())
return false;
if (d->isString() && name == QStringLiteral("length"))
return true;
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::Scope scope(obj->engine());
QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name));
return obj->hasProperty(key);
}
return prototype().hasProperty(name);
}
/*!
* Returns \c true if this QJSManagedValue has a property \a name, otherwise
* returns \c false. The properties of the prototype chain are not considered.
*/
bool QJSManagedValue::hasOwnProperty(const QString &name) const
{
if (!d || d->isNullOrUndefined())
return false;
if (d->isString() && name == QStringLiteral("length"))
return true;
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::Scope scope(obj->engine());
QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name));
return obj->getOwnProperty(key) != QV4::Attr_Invalid;
}
return false;
}
/*!
* Returns the property \a name of this QJSManagedValue. The prototype chain
* is searched if the property is not found on the actual object.
*/
QJSValue QJSManagedValue::property(const QString &name) const
{
if (!d)
return QJSValue();
if (d->isNullOrUndefined()) {
QV4::ExecutionEngine *e = v4Engine(d);
e->throwTypeError(QStringLiteral("Cannot read property '%1' of null").arg(name));
return QJSValue();
}
if (QV4::String *string = d->as<QV4::String>()) {
if (name == QStringLiteral("length"))
return QJSValue(string->d()->length());
}
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::Scope scope(obj->engine());
QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name));
return QJSValuePrivate::fromReturnedValue(obj->get(key));
}
return prototype().property(name);
}
/*!
* Sets the property \a name to \a value on this QJSManagedValue. This can only
* be done on JavaScript values of type \c object. Furhermore, \a value has to be
* either a primitive or belong to the same engine as this value.
*/
void QJSManagedValue::setProperty(const QString &name, const QJSValue &value)
{
if (!d)
return;
if (d->isNullOrUndefined()) {
v4Engine(d)->throwTypeError(
QStringLiteral("Value is null and could not be converted to an object"));
}
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::Scope scope(obj->engine());
QV4::ExecutionEngine *v4 = QJSValuePrivate::engine(&value);
if (Q_UNLIKELY(v4 && v4 != scope.engine)) {
qWarning("QJSManagedValue::setProperty() failed: "
"Value was created in different engine.");
return;
}
QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name));
QV4::ScopedValue val(scope, QJSValuePrivate::convertToReturnedValue(scope.engine, value));
obj->put(key, val);
}
}
/*!
* Deletes the property \a name from this QJSManagedValue. Returns \c true if
* the deletion succeeded, or \c false otherwise.
*/
bool QJSManagedValue::deleteProperty(const QString &name)
{
if (!d)
return false;
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::Scope scope(obj->engine());
QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name));
return obj->deleteProperty(key);
}
return false;
}
/*!
* Returns \c true if this QJSManagedValue has an array index \a arrayIndex,
* otherwise returns \c false. The properties of the prototype chain are
* considered.
*/
bool QJSManagedValue::hasProperty(quint32 arrayIndex) const
{
if (!d || d->isNullOrUndefined())
return false;
if (QV4::String *string = d->as<QV4::String>())
return arrayIndex < quint32(string->d()->length());
if (QV4::Object *obj = d->as<QV4::Object>()) {
bool hasProperty = false;
if (arrayIndex == std::numeric_limits<quint32>::max())
obj->get(obj->engine()->id_uintMax(), &hasProperty);
else
obj->get(arrayIndex, &hasProperty);
return hasProperty;
}
return prototype().hasProperty(arrayIndex);
}
/*!
* Returns \c true if this QJSManagedValue has an array index \a arrayIndex,
* otherwise returns \c false. The properties of the prototype chain are not
* considered.
*/
bool QJSManagedValue::hasOwnProperty(quint32 arrayIndex) const
{
if (!d || d->isNullOrUndefined())
return false;
if (QV4::String *string = d->as<QV4::String>())
return arrayIndex < quint32(string->d()->length());
if (QV4::Object *obj = d->as<QV4::Object>()) {
if (arrayIndex == std::numeric_limits<quint32>::max()) {
return obj->getOwnProperty(obj->engine()->id_uintMax()->toPropertyKey())
!= QV4::Attr_Invalid;
} else {
return obj->getOwnProperty(QV4::PropertyKey::fromArrayIndex(arrayIndex))
!= QV4::Attr_Invalid;
}
}
return false;
}
/*!
* Returns the property stored at \a arrayIndex of this QJSManagedValue. The
* prototype chain is searched if the property is not found on the actual
* object.
*/
QJSValue QJSManagedValue::property(quint32 arrayIndex) const
{
if (!d || d->isNullOrUndefined())
return QJSValue();
if (QV4::String *string = d->as<QV4::String>()) {
const QString qString = string->toQString();
if (arrayIndex < quint32(qString.size()))
return qString.sliced(arrayIndex, 1);
return QJSValue();
}
if (QV4::Object *obj = d->as<QV4::Object>()) {
if (arrayIndex == std::numeric_limits<quint32>::max())
return QJSValuePrivate::fromReturnedValue(obj->get(obj->engine()->id_uintMax()));
else
return QJSValuePrivate::fromReturnedValue(obj->get(arrayIndex));
}
return prototype().property(arrayIndex);
}
/*!
* Stores the \a value at \a arrayIndex in this QJSManagedValue. This can only
* be done on JavaScript values of type \c object, and it's not recommended if the
* value is not an array. Furhermore, \a value has to be either a primitive or
* belong to the same engine as this value.
*/
void QJSManagedValue::setProperty(quint32 arrayIndex, const QJSValue &value)
{
if (!d)
return;
if (QV4::Object *obj = d->as<QV4::Object>()) {
QV4::ExecutionEngine *v4 = QJSValuePrivate::engine(&value);
if (Q_UNLIKELY(v4 && v4 != obj->engine())) {
qWarning("QJSManagedValue::setProperty() failed: "
"Value was created in different engine.");
return;
}
v4 = obj->engine(); // in case value was primitive
QV4::Scope scope(v4);
QV4::ScopedValue v(scope, QJSValuePrivate::convertToReturnedValue(v4, value));
obj->put(arrayIndex, v);
}
}
/*!
* Deletes the value stored at \a arrayIndex from this QJSManagedValue. Returns
* \c true if the deletion succeeded, or \c false otherwise.
*/
bool QJSManagedValue::deleteProperty(quint32 arrayIndex)
{
if (!d)
return false;
if (QV4::Object *obj = d->as<QV4::Object>())
return obj->deleteProperty(QV4::PropertyKey::fromArrayIndex(arrayIndex));
return false;
}
static const QV4::FunctionObject *functionObjectForCall(QV4::Value *d)
{
if (Q_UNLIKELY(!d)) {
qWarning("QJSManagedValue: Calling a default-constructed or moved-from managed value"
"should throw an exception, but there is no engine to receive it.");
return nullptr;
}
if (const QV4::FunctionObject *f = d->as<QV4::FunctionObject>())
return f;
v4Engine(d)->throwTypeError(QStringLiteral("Value is not a function"));
return nullptr;
}
/*!
* If this QJSManagedValue represents a JavaScript FunctionObject, calls it with
* the given \a arguments, and returns the result. Otherwise returns a
* JavaScript \c undefined value.
*
* The \a arguments have to be either primitive values or belong to the same
* QJSEngine as this QJSManagedValue. Otherwise the call is not carried
* out and a JavaScript \c undefined value is returned.
*/
QJSValue QJSManagedValue::call(const QJSValueList &arguments) const
{
const QV4::FunctionObject *f = functionObjectForCall(d);
if (!f)
return QJSValue();
QV4::ExecutionEngine *engine = f->engine();
QV4::Scope scope(engine);
QV4::JSCallArguments jsCallData(scope, arguments.size());
*jsCallData.thisObject = engine->globalObject;
int i = 0;
for (const QJSValue &arg : arguments) {
if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) {
qWarning("QJSManagedValue::call() failed: Argument was created in different engine.");
return QJSValue();
}
jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg);
}
return QJSValuePrivate::fromReturnedValue(f->call(jsCallData));
}
/*!
* If this QJSManagedValue represents a JavaScript FunctionObject, calls it on
* \a instance with the given \a arguments, and returns the result. Otherwise
* returns a JavaScript \c undefined value.
*
* The \a arguments and the \a instance have to be either primitive values or
* belong to the same QJSEngine as this QJSManagedValue. Otherwise the call is
* not carried out and a JavaScript \c undefined value is returned.
*/
QJSValue QJSManagedValue::callWithInstance(const QJSValue &instance,
const QJSValueList &arguments) const
{
const QV4::FunctionObject *f = functionObjectForCall(d);
if (!f)
return QJSValue();
QV4::ExecutionEngine *engine = f->engine();
if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, instance))) {
qWarning("QJSManagedValue::callWithInstance() failed: "
"Instance was created in different engine.");
return QJSValue();
}
QV4::Scope scope(engine);
QV4::JSCallArguments jsCallData(scope, arguments.size());
*jsCallData.thisObject = QJSValuePrivate::convertToReturnedValue(engine, instance);
int i = 0;
for (const QJSValue &arg : arguments) {
if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) {
qWarning("QJSManagedValue::callWithInstance() failed: "
"Argument was created in different engine.");
return QJSValue();
}
jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg);
}
return QJSValuePrivate::fromReturnedValue(f->call(jsCallData));
}
/*!
* If this QJSManagedValue represents a JavaScript FunctionObject, calls it as
* constructor with the given \a arguments, and returns the result. Otherwise
* returns a JavaScript \c undefined value.
*
* The \a arguments have to be either primitive values or belong to the same
* QJSEngine as this QJSManagedValue. Otherwise the call is not carried
* out and a JavaScript \c undefined value is returned.
*/
QJSValue QJSManagedValue::callAsConstructor(const QJSValueList &arguments) const
{
const QV4::FunctionObject *f = functionObjectForCall(d);
if (!f)
return QJSValue();
QV4::ExecutionEngine *engine = f->engine();
QV4::Scope scope(engine);
QV4::JSCallArguments jsCallData(scope, arguments.size());
int i = 0;
for (const QJSValue &arg : arguments) {
if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) {
qWarning("QJSManagedValue::callAsConstructor() failed: "
"Argument was created in different engine.");
return QJSValue();
}
jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg);
}
return QJSValuePrivate::fromReturnedValue(f->callAsConstructor(jsCallData));
}
/*!
* \internal
*
* Retrieves the JavaScript meta type of this value. The JavaScript meta type
* represents the layout of members in an object. Instantiating a meta type is
* faster than re-constructing the same object using a sequence of setProperty()
* calls on a new object.
*
* \sa members(), instantiate()
*/
QJSManagedValue QJSManagedValue::jsMetaType() const
{
if (!d)
return QJSManagedValue();
QJSManagedValue result(v4Engine(d));
if (QV4::Managed *m = d->as<QV4::Managed>())
*result.d = m->internalClass();
return result;
}
/*!
* \internal
*
* If this value is a JavaScript meta type, retrieves the names of its members
* The ordering of the names corresponds to the ordering of the values to be
* passed to instantiate().
*
* If the value is not a meta type, an empty list is returned.
*
* \sa isMetaType(), metaType(), instantiate()
*/
QStringList QJSManagedValue::jsMetaMembers() const
{
if (!d)
return {};
if (QV4::InternalClass *c = d->as<QV4::InternalClass>()) {
const auto heapClass = c->d();
const int size = heapClass->size;
QStringList result;
result.reserve(size);
QV4::Scope scope(c->engine());
for (int i = 0; i < size; ++i) {
QV4::ScopedValue key(scope, heapClass->keyAt(i));
result.append(key->toQString());
}
return result;
}
return {};
}
/*!
* \internal
*
* If this value is a JavaScript meta type, instantiates it using the
* \a values, and returns the result. Otherwise returns undefined.
*
* The values are expected in the same order as the keys in the return value of
* members(), and that is the order in which properties were added to the object
* this meta type originally belongs to.
*
* \sa members(), metaType(), isMetaType().
*/
QJSManagedValue QJSManagedValue::jsMetaInstantiate(const QJSValueList &values) const
{
if (!d)
return {};
if (QV4::InternalClass *c = d->as<QV4::InternalClass>()) {
QV4::ExecutionEngine *engine = c->engine();
QJSManagedValue result(engine);
*result.d = c->engine()->newObject(c->d());
QV4::Object *o = result.d->as<QV4::Object>();
QV4::Scope scope(engine);
QV4::ScopedValue val(scope);
for (uint i = 0, end = qMin(qsizetype(c->d()->size), values.size()); i < end; ++i) {
const QJSValue &arg = values[i];
if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) {
qWarning("QJSManagedValue::instantiate() failed: "
"Argument was created in different engine.");
return QJSManagedValue();
}
val = QJSValuePrivate::convertToReturnedValue(engine, arg);
o->setProperty(i, val);
}
return result;
}
return {};
}
QJSManagedValue::QJSManagedValue(QV4::ExecutionEngine *engine) :
d(engine->memoryManager->m_persistentValues->allocate())
{
}
QT_END_NAMESPACE