[CMake] Patch to FindQt4.cmake for supporting moc compiler options

[Miguel A. Figueroa-Villanueva]

On 11/27/07, clinton wrote:
> On Saturday 24 November 2007 3:23:16 pm Miguel A. Figueroa-Villanueva wrote:
> > Hello,
> >
> > I would like to propose the following patch or something similar to
> > add support for moc compiler options. Currently, one can do the
> > following:
> >
> > SET(moc-sources foo.h bar.h)
> > QT4_WRAP_CPP(sources ${moc-sources})
> >
> > With the attached patch one could pass also options to be invoked with
> > each moc-source:
> >
> > QT4_WRAP_CPP(sources ${moc-sources} OPTIONS -DMYDEF)
> >
> > The current approach is a simplified one to support the following syntax:
> >
> > QT4_WRAP_CPP(<outputfiles> <moc-sources> [OPTIONS opt1 opt2 ...])
> >
> > This could also be applied to QT4_WRAP_UI(...).
> >
> > --Miguel
>
> I'm curious what the convention is for adding arguments to custom commands in
> macros.

Don't know... But I looked at how cmake commands work and tried to
provide something along those lines.

> To compare, I see the FindSWIG.cmake/UseSWIG.cmake allow setting the
> CMAKE_SWIG_FLAGS variable.  The advantage of that is that it applies to all
> calls of the macro.

The problem I see with this is that you depend on the value of say
QT4_MOC_FLAGS and then scoping issues come into play. For example, if
you set this flag then in a later call you will have it affect that
call unintentionally unless you clear it. It's then complicated when
you consider INCLUDE files. So, my thoughts were to send the options
to the macro every time you need them and not worry about the variable
scope ramifications and other use cases.

Just my two cents,
--Miguel