[Development] Clarification on Mac 10.6 support for Qt 5.2

[Ziller Eike]

> ________________________________________
> From: Thiago Macieira [thiago.macieira at intel.com]
> Sent: 05 June 2013 19:45
> To: development at qt-project.org
> Subject: Re: [Development] Clarification on Mac 10.6 support for Qt 5.2
> 
> On quarta-feira, 5 de junho de 2013 15.49.53, Tor Arne Vestbø wrote:
> > On 6/5/13 12:49 , Gustavsen Richard wrote:
> > >> From reading this thread, it seems that 10.6 support is pretty
> > >> important. But right now you need to build Qt from sources yourself
> > >> to get it.
> > >
> > > Is this good enough? It sounds like it would be better if the binary
> > > package continued with 10.6 support when so many users still has that
> > > version. Those that need C++11 and don't need to target 10.6 could
> > > still build Qt themselves (rather than the opposite)...
> >
> > I agree that the SDK should perhaps span to include 10.6 deployment support.

AFAIK QtWebKit no longer supports video on 10.6, so that would mean that
there would need to be a 10.6 specific SDK version, or the SDK would not support this on *any* Mac OS version (since you can't configure QtWebKit in a way that it would support that on 10.7+ and still run on 10.6).
I don't know if the latter would be acceptable or not.

> > Technically that's up to the people building the binary SDK packages, if
> > they configure with -no-c++11 or not. Qt's configure will by default
> > detect if it's supported, and adjusts the deployment target accordingly.
> 
> Since changing to libc++ could be a binary incompatible change[*], we should
> probably stick to libstdc++ for now and disable C++11 in Qt's build for OS X.
> Since we're right now building with GCC 4.2, no C++11 is in use in those
> builds anyway, so there's no loss. And there will probably be a gain, by
> upgrading the compiler.

Just for clarification, the default mkspec of Qt 5 on Mac is clang (without libc++),
not gcc/g++ .

> [*] it does not affect Qt's ABI, but it might affect other libraries that the
> user is compiling against.
> 
> --
> Thiago Macieira - thiago.macieira (AT) intel.com
>   Software Architect - Intel Open Source Technology Center


--
Eike Ziller
Senior Software Engineer

Digia Germany GmbH
Rudower Chaussee 13, D-12489 Berlin
Sitz der Gesellschaft: Berlin, Registergericht: Amtsgericht Charlottenburg, HRB 144331 B,
Geschäftsführer: Mika Pälsi, Juha Varelius, Anja Wasenius