-mms-bitfields revisited

[Patrick Spendrin]

Bernhard Reiter schrieb:
> Am Dienstag, 16. Juni 2009 14:08:57 schrieb Ralf Habacker:
>>> It basically tell
>>> gcc to be msvc compatible, for C libs, if I understand correctly, and
>>> should cause no harm, provided everything is built with it consistently.
> 
> Or rephrased differently, using the machine flag "-m" set to "ms-bitfields"
> the resulting binary will be compatible with the ABI of windows (aka dlls from 
> Microsoft-Compilers).
> 
> http://gcc.gnu.org/onlinedocs/gcc-4.4.0/gcc/Type-Attributes.html#i386-Type-Attributes :
> 
>     Currently -m[no-]ms-bitfields is provided for the Microsoft Windows X86 
>     compilers to match the native Microsoft compiler.
> 
> (Credits go to Werner and Marcus for explaining the issue to me.)
> 
>>> Let me know how I should proceed with this. This then leaves the question
>>> of Qt. Nokians, any opinion on that? Is it maybe even already in there,
>>> the flag? 
>> According to http://code.google.com/p/cocotron/issues/detail?id=137
>> adding this option will result into an binary incompatible change, which
>> means *all* packages affected by this BIC should be rebuild at the same
>> time.
> 
> Yes.
> 
> The problem mainly will create problems with using C libraries using somehow 
> packed bitfields in structs or so and of course both sides using a different 
> ABI.
> 
> It might be that current builds of KDE (without the right ABI) on windows 
> interfacing with DLLs in the microsoft compiler layout will have somehow 
> hidden defects because of this issue already.
The following problems I do see with this change:
1) binary compatible problems shouldn't be a problem themselves. The
much bigger question is the following: We do use libraries from third
parties for the obvious sake of not needing to care about them on our own.
Do we need to recompile those (that might not be compiled with
ms-bitfield)? If yes how can we check which are needed to be recompiled?
And who can shoulder these rebuilds?
I would prefer to have those questions answered before changing this.

Patrick
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Kde-windows mailing list
> Kde-windows at kde.org
> https://mail.kde.org/mailman/listinfo/kde-windows