[Development] Q_OBJECT and "override"

[Bornemann Joerg]

> 1) Add "override" (or rather Q_DECL_OVERRIDE) to the definition of
> Q_OBJECT *and* all QObject-derived classes in Qt.
[...]
> 2) Remove "override" from all QObject-derived classes in Qt.
[...]
> 3) Explicitly disable the warning in the clang mkspecs.
[...]
> 4) Let users deal with the problem by making them turn the warning off.
[...]

1) is the thing to do, but OTOH it's a lot of work with questionable gain.
2) and 4) are very wrong. IMO, we shouldn't do this.
3) could be a good compromise. There's a variant of this solution by turning the warning off 
at the beginning of every header and turning it on again at the end.
We once had the QT_{BEGIN|END}_HEADER macros which could expand to

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wannoyingwarning"

and repectively

#pragma clang diagnostic pop

This way the warning can be turned on for user code.


BR,

Joerg