1 QQmlContextData::isValid() const qqmlcontext_p.h 122 0x1017f08cf 
  2 QQmlContext::isValid() const qqmlcontext.cpp 233 0x101822efc 
  3 QQmlEngineDebugServiceImpl::buildObjectList(QDataStream&, QQmlContext *, QList<QPointer<QObject>> const&) qqmlenginedebugservice.cpp 392 0x10f79a81f 
  4 QQmlEngineDebugServiceImpl::buildObjectList(QDataStream&, QQmlContext *, QList<QPointer<QObject>> const&) qqmlenginedebugservice.cpp 416 0x10f79a932 
  5 QQmlEngineDebugServiceImpl::buildObjectList(QDataStream&, QQmlContext *, QList<QPointer<QObject>> const&) qqmlenginedebugservice.cpp 416 0x10f79a932 
  6 QQmlEngineDebugServiceImpl::processMessage(QByteArray const&) qqmlenginedebugservice.cpp 536 0x10f796abc 
  7 QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<QByteArray const&>, void, void (QQmlEngineDebugServiceImpl:: *)(QByteArray const&)>::call(void (QQmlEngineDebugServiceImpl:: *)(QByteArray const&), QQmlEngineDebugServiceImpl *, void * *) qobjectdefs_impl.h 134 0x10f7a1265 
  8 void QtPrivate::FunctionPointer<void (QQmlEngineDebugServiceImpl:: *)(QByteArray const&)>::call<QtPrivate::List<QByteArray const&>, void>(void (QQmlEngineDebugServiceImpl:: *)(QByteArray const&), QQmlEngineDebugServiceImpl *, void * *) qobjectdefs_impl.h 167 0x10f7a11b0 
  9 QtPrivate::QSlotObject<void (QQmlEngineDebugServiceImpl:: *)(QByteArray const&), QtPrivate::List<QByteArray const&>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void * *, bool *) qobjectdefs_impl.h 396 0x10f7a10d6 
  10 QtPrivate::QSlotObjectBase::call(QObject *, void * *) qobjectdefs_impl.h 376 0x10225b196 
  11 QMetaCallEvent::placeMetaCall(QObject *) qobject.cpp 504 0x102297958 
  12 QObject::event(QEvent *) qobject.cpp 1251 0x102299668 
  13 QCoreApplicationPrivate::notify_helper(QObject *, QEvent *) qcoreapplication.cpp 1197 0x10224ba26 
  14 doNotify(QObject *, QEvent *) qcoreapplication.cpp 1138 0x10224b50a 
  15 QCoreApplication::notify(QObject *, QEvent *) qcoreapplication.cpp 1124 0x10224b5d7 
  16 QGuiApplication::notify(QObject *, QEvent *) qguiapplication.cpp 1770 0x102890166 
  17 QCoreApplication::notifyInternal2(QObject *, QEvent *) qcoreapplication.cpp 1048 0x10224b425 
  18 QCoreApplication::sendEvent(QObject *, QEvent *) qcoreapplication.h 234 0x10224ce78 
  19 QCoreApplicationPrivate::sendPostedEvents(QObject *, int, QThreadData *) qcoreapplication.cpp 1745 0x10224ccfe 
  20 QCoreApplication::sendPostedEvents(QObject *, int) qcoreapplication.cpp 1599 0x10224bebf 
  21 QCocoaEventDispatcherPrivate::processPostedEvents() qcocoaeventdispatcher.mm 897 0x108a2f87e 
  22 QCocoaEventDispatcherPrivate::postedEventsSourceCallback(void *) qcocoaeventdispatcher.mm 919 0x108a306ff 
  23 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 0x7fff52cf0405 
  24 __CFRunLoopDoSource0 0x7fff52cf03ab 
  25 __CFRunLoopDoSources0 0x7fff52cd3e51 
  26 __CFRunLoopRun 0x7fff52cd33fa 
  27 CFRunLoopRunSpecific 0x7fff52cd2ce4 
  28 RunCurrentEventLoopInMode 0x7fff51f6c895 
  29 ReceiveNextEventCommon 0x7fff51f6c5cb 
  30 _BlockUntilNextEventMatchingListInModeWithFilter 0x7fff51f6c348 
  31 _DPSNextEvent 0x7fff5022995b 
  32 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] 0x7fff502286fa 
  33 -[NSApplication run] 0x7fff5022275d 
  34 QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) qcocoaeventdispatcher.mm 430 0x108a2e530 
  35 QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) qeventloop.cpp 136 0x10224566b 
  36 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) qeventloop.cpp 214 0x10224587b 
  37 QCoreApplication::exec() qcoreapplication.cpp 1336 0x10224bd2c 
  38 QGuiApplication::exec() qguiapplication.cpp 1761 0x102890106 
  39 main main.cpp 327 0x100011707 
  40 start 0x7fff7fd68085

inline bool isValid() const 

{     return engine && (!isInternal || !contextObject || !QObjectPrivate::get(contextObject)->wasDeleted); }