[FFmpeg-devel] [PATCH] configure: support MSYS2

[Hendrik Leppkes]

On Sun, Jan 25, 2015 at 7:44 PM, James Almer <jamrial at gmail.com> wrote:

> On 25/01/15 2:47 PM, Hendrik Leppkes wrote:
> > On Sun, Jan 25, 2015 at 6:43 PM, Michael Niedermayer <michaelni at gmx.at>
> > wrote:
> >
> >> On Sun, Jan 25, 2015 at 05:02:58PM +0100, Reimar Döffinger wrote:
> >>> On Sun, Jan 25, 2015 at 03:59:12PM +0100, Hendrik Leppkes wrote:
> >>>> On Sun, Jan 25, 2015 at 3:26 PM, Hendrik Leppkes <h.leppkes at gmail.com
> >
> >>>> wrote:
> >>>>
> >>>>> MSYS2 uses a system name of "MSYS_NT-6.3" instead of
> >> "MINGW32_NT-6.3" in
> >>>>> MSYS1.
> >>>>>
> >>>>
> >>>> Apparently this isn't quite correct, and you have to start MSYS2 with
> a
> >>>> special batch file that overrides this for you.
> >>>> Just running bash.exe or sh.exe from a DOS prompt results in this and
> >> is
> >>>> apparently considered "wrong usage".
> >>>
> >>> I don't really see anything wrong with this, however I'd rather have
> >>> a compiler-based detection.
> >>> I.e. if the compiler define __MINGW32__ set the host to mingw (unless
> >>> set explicitly).
> >>
> >>> This should also address my other annoyance that you have to specify
> >>> --host when it really should be obvious that you are cross-compiling to
> >>> MINGW for example.
> >>
> >> i dont use "--host*" for my mingw building
> >> just -cc='ccache x86_64-w64-mingw32-gcc' --arch=x86_64
> --target-os=mingw32
> >> --cross-prefix=x86_64-w64-mingw32- --target_exec=wine
> >>
> >> the rest i use should not be mingw specific
> >>
> >>
> > I've never had to specify --host things either, the only problem with
> MSYS2
> > I ran into was that you still need to specify --target-os unless you use
> > their fancy batch file, and that tripped me up a bit.
> > Never a problem with old MSYS and my own gcc build.
>
> As you said the old MSYS uses "MINGW32" as part of the system name, while
> the
> normal batch file for MSYS2 sets it as "MSYS".
> If you instead use the x86 batch file it will be set as "MINGW32", or
> "MINGW64"
> if you use the x86_64 batch file.
>
> The different batch files exist not just to change the output of uname,
> but also
> to change the PATH environment variable too include either /mingw32 or
> /mingw64
> respectively. Their package manager offers a complete toolchain and
> precompiled
> libraries, which get installed in one of the two folders above.
> Ideally speaking, if you don't want to use their gcc toolchains, you should
> install your own in some other folder (/usr/local, /opt, etc) and use the
> normal
> batch file.
>
> configure currently only checks for mingw32 since that's what MSYS sets,
> so it
> needs to be updated to also check for mingw64 and msys, so this patch is
> IMO
> correct but incomplete as its missing the check for the former.
>
>
My problem really is with their choice of default. Apparently (or so I am
told), the MSYS_* string is for building things actually for MSYS itself,
which is imho a bad default.
If I just call sh/bash.exe (like I do in a multitude of my scripts), I
wouldn't want that to be the default value, especially since it breaks with
compat for all sorts of projects (we're not the only project with that
problem)

- Hendrik