QEvent: start to de-inline copy ctor and clone() of all subclasses

There's no advantage to them being inline: Absent de-virtualisation,
clone() is only supposed to be called through the vtable, and the copy
ctor is only supposed to be used in the implementation of clone().

And when the compiler de-virtualises, we don't want the code
duplication associated with inlining.

Enforce this by introducing new macros to hide the boilerplate.

This fixes missing out-of-line dtors in:
- QSinglePointEvent
- QApplicationStateChangeEvent
- QFutureCallOutEvent

Wrong covariant return in:
- QFutureCallOutEvent

And missing clone() reimplementations in:
- QCloseEvent
- QIconDragEvent
- QShowEvent
- QHideEvent
- QDragEnterEvent
- QDragLeaveEvent

While these don't carry extra data or members, a dynamic_cast of the
result of clone() as well as using the expected covariant return value
would fail:

   QShowEvent *e = ~~~;
   QShowEvent *e2 = e->clone(); // ERROR: converting QEvent* to QShowEvent*

Check that reimplementing clone() is binary compatible (covariant
returns may change the numerical pointer value returned, cf.
https://community.kde.org/Policies/Binary_Compatibility_Issues_With_C%2B%2B).

The copy-assignment operator stays inline for the time being, as the
goal is to = delete it in the future.

This patch covers, roughly, QtCore and QtGui.

[ChangeLog][QtGui][QEvent subclasses] Fixed missing clone()
reimplementations on QCloseEvent, QIconDragEvent, QShowEvent,
QHideEvent, QDragEnterEvent, and QDragLeaveEvent.

Task-number: QTBUG-45582
Task-number: QTBUG-97601
Change-Id: Ib8a0519dbe85a7a8da61050d48be338004dfa69a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 4 insertions, 23 deletions

diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index 34b57bb4f8..2289938d4b 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -559,12 +559,7 @@ QTimerEvent::QTimerEvent(int timerId)
     : QEvent(Timer), id(timerId)
 {}
 
-/*!
-    \internal
-*/
-QTimerEvent::~QTimerEvent()
-{
-}
+Q_IMPL_EVENT_COMMON(QTimerEvent)
 
 /*!
     \fn int QTimerEvent::timerId() const
@@ -606,12 +601,7 @@ QChildEvent::QChildEvent(Type type, QObject *child)
     : QEvent(type), c(child)
 {}
 
-/*!
-    \internal
-*/
-QChildEvent::~QChildEvent()
-{
-}
+Q_IMPL_EVENT_COMMON(QChildEvent)
 
 /*!
     \fn QObject *QChildEvent::child() const
@@ -663,12 +653,7 @@ QDynamicPropertyChangeEvent::QDynamicPropertyChangeEvent(const QByteArray &name)
 {
 }
 
-/*!
-    \internal
-*/
-QDynamicPropertyChangeEvent::~QDynamicPropertyChangeEvent()
-{
-}
+Q_IMPL_EVENT_COMMON(QDynamicPropertyChangeEvent)
 
 /*!
     \fn QByteArray QDynamicPropertyChangeEvent::propertyName() const
@@ -687,11 +672,7 @@ QDeferredDeleteEvent::QDeferredDeleteEvent()
     , level(0)
 { }
 
-/*!
-    \internal
-*/
-QDeferredDeleteEvent::~QDeferredDeleteEvent()
-{ }
+Q_IMPL_EVENT_COMMON(QDeferredDeleteEvent)
 
 /*! \fn int QDeferredDeleteEvent::loopLevel() const