[Development] Prebuilt 32-bit versjon for MSVC 2017

[Thiago Macieira]

On Thursday, 22 February 2018 01:39:50 PST Tim Blechmann wrote:
> > Currently Qt ships with 32-bit binaries for MSVC 2015, but not for
> > MSVC 2017. The Qt Company have received requests for adding prebuilt
> > 32-bit binaries also for MSVC 2017. By adding more prebuilt binaries,
> > we increase the complexity, and add to the overall maintenance of our
> > QA system. Our preferred approach would be to add binaries for MSVC
> > 2017 and remove the binaries for MSVC 2015, as the numbers of
> > binaries in the build remains the same. It will still be possible to
> > manually build Qt for MSVC 2015, in the same way as it is possible to
> > manually build for MSVC 2017 today. Feedback and viewpoints are much
> > appreciated and will enable us to make the best possible decision.
> 
> the ABI of msvc2015 and msvc2017 is the same. so unlike earlier msvc
> releases, one can mix binaries from both compilers.

In theory.

In practice, we've found that it doesn't work for Qt, at least because of the 
Q_COMPILER_xxx defines as MSVC 2015 has fewer C++11 features than 2017.

> in theory. in practice there is a still unresolved compiler bug in
> msvc2017 (we've experienced it only with static libs and debug builds,
> but i'm not sure if it has any implication on the binaries you want to
> release):

That's another one: everything compiled with MSVC 2017 has incorrect 
initialisation sequneces. You're running on borrowed time, until Microsoft 
fixes it (they're saying they'll fix it in the 15.7 release in May).

Note I did not say "static".

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center