[Qt-interest] qmake and scope: prevent moc from moc'ing file?

[Konstantin Tokarev]

10.02.2011, 17:13, Oliver.Knoll at comit.ch:
> Hi,
>
> I hit a rather esoteric problem: it seems that when running qmake it does not prevent moc from running on files which are in a different scope. That is on Qt 4.7.1 (MinGW binary build).
>
> This is my scenario: I have an interface Foo.h, which is implemented by platform-specific code, as in Foo_Windows, Foo_Mac etc. The source and header files are naturally placed in qmake scopes, as in:
>
> if (macx) {
>     HEADERS += Foo_Mac.h
>     SOURCES += Foo_Mac.cpp
> } else:win32 {
>     HEADERS += Foo_Windows.h
>     SOURCES += Foo_Windows.cpp
> } etc.
>
> This compiles and links all fine, as expected.
>
> Now for the Mac implementation - and currently only for the Mac - I wanted to also subclass from QObject, so I did:
>
> // Foo_Mac.h
> class Foo : public QObject, public Foo
> {
>     Q_OBJECT // workaround: remove this (if possible)
> public:
>     ....
> };
>
> Now it turns out that when compiling the code on e.g. Windows I get linker errors, because the moc also produces code from this Foo_Mac.h (even though that header is put in a different scope).
>
> Off course in my case I get away by removing the Q_OBJECT macro from Foo_Mac.h. This is possible since all I want to do is to install this class as an event filter on another QObject - so I don't need meta class information, nor signals/slots. I could also make the interface class Foo.h inherit from QObject instead, and add the Q_OBJECT macro there, if needed. But also then I would probably hit the same problem again, should I want to add the Q_OBJECT macro also to it's implementing classes (because I would need the meta class information there as well, for instance).
>
> So it seems that qmake does not take the scopes into account when generating the moc steps which looks like a qmake bug to me? Or at least an "unsupported feature"? Google did not turn up with anything useful. Or am I doing something wrong?

You can simply don't add this header file to HEADERS

-- 
Regards,
Konstantin