[Interest] Configure Qt5

[K. Frank]

Hello Graham (and Thiago)!

On Wed, Nov 7, 2012 at 5:55 AM, Thiago Macieira <thiago... at ...> wrote:
> On quarta-feira, 7 de novembro de 2012 09.21.55, Graham Labdon wrote:
>> Hi
>> I downloaded Qt5 and ran the following configure command
>> configure -platform win32-g++
>> This gave me the following error
>>
>> cc1plus.exe: error: unrecognized command line option
>> "-fno-keep-inline-dllexport" mingw32-make: ***
>> [tmp/obj/debug_shared/arch.o] Error 1
>>
>> What can I do to fix this?
>
> Option 1:
>  use a MinGW version that supports that option.
>
> Option 2:
>  remove the option from mkspecs/win32-g++/qmake.conf

Let me comment briefly on why that option might be there and on my
experience:

With various versions of Qt 4.8 (not Qt 5) and various versions of
mingw-w64 gcc 4.7, I have had trouble with "memory exhausted"
errors when building Qt (if I remember correctly, when linking
QtGuid4.dll).  I was barely able to build Qt on a 4 Gb (windows)
machine and was unable to build it without tweaking options on
a 2 Gb machine.

To build it on the 2 Gb machine, I used some memory-reducing
compile options, in particular, "-fno-keep-inline-dllexport".

So I am guessing that this option has been added to the default
Qt 5 build configuration to address this issue.

In my case, one of Ruben's 4.7 mingw-w64 builds does support
"-fno-keep-inline-dllexport", so Thiago's option 1 is probably
the way to go.

If you do use a gcc without that doesn't support
"-fno-keep-inline-dllexport" (Thiago's option 2) you should be aware
that the link step may need a lot of memory, and plan to build on
a big machine or look to other memory-reducing compile options
and / or build configuration.

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

Good luck.


K. Frank