[Development] Choosing a new MinGW for Qt 5

[Jonathan Liu]

On 31/08/2012 2:16 AM, Thiago Macieira wrote:
> On quinta-feira, 30 de agosto de 2012 17.25.24, Pau Garcia i Quiles wrote:
>> There are more differences than that. There are differences in
>> features, such as threading support, large-file support, etc.
>> Mingw-w64 is usually ahead of any other in terms of features.
>
> My suggestion on how to proceed is to choose one that offers the following or
> most of the following:
>
>   - most recent GCC (4.7 preferably, 4.6 if not)
I had a problem with MinGW-builds GCC 4.7.1 32-bit. Qt Creator would 
crash if I opened the Qt resource editor if Qt 4.8.2 and Qt Creator 
2.5.2 were compiled with it. MinGW-builds GCC 4.7.1 64-bit didn't crash.

I switched to MinGW-builds 4.6.3 for both 32-bit and 64-bit and it seems 
to be working fine. Also, GCC 4.7.x has problem where it runs out of 
memory in some cases (https://bugs.archlinux.org/task/28329).

>   - make with -j support

Patch for that here: 
http://www.mail-archive.com/make-w32@gnu.org/msg02283.html. I use this 
regularly with 8 threads (set MAKEFLAGS=-j8).

It is also in GNU Make CVS.

>   - if this exists: can link to .dll directly, instead of import libs

I've done this before linking to some proprietary C dlls created by 
Visual C++. YMMV.

>
> We should choose one version to be the reference platform and work on making
> it Tier 1. We shouldn't have two versions, that duplicates work.

I agree.

Some other MinGW-related notes follow.

Compiling WebKit fails due to mingw32-make using temporary batch files 
which are subject to 8191 character limit per line. Can be fixed using 
instructions at: 
http://old.nabble.com/Re%3A-command-line-limit-in-mingw-make-p33909533.html

ICU can be compiled with MinGW-w64 after applying:
http://bugs.icu-project.org/trac/changeset/31770/icu/trunk/source/tools/toolutil/pkg_genc.c?format=diff&new=31770

Regards,
Jonathan