[FFmpeg-devel] FATE failure on mingw gcc-4.2.4

[Ramiro Polla]

On Thu, Mar 11, 2010 at 7:29 AM, Frank Barchard <fbarchard at google.com> wrote:
> On Thu, Mar 11, 2010 at 1:43 AM, Ramiro Polla <ramiro.polla at gmail.com>wrote:
>> On Thu, Mar 11, 2010 at 6:26 AM, Ramiro Polla <ramiro.polla at gmail.com>
>> wrote:
>> > On Thu, Mar 11, 2010 at 6:24 AM, Frank Barchard <fbarchard at google.com>
>> wrote:
>> >> On Mon, Mar 8, 2010 at 8:02 PM, M?ns Rullg?rd <mans at mansr.com> wrote:
>> >>
>> >>> The build failures on mingw with gcc 4.2.4 are caused by the recent
>> >>> addition of -Werror=missing-prototypes triggering an error in
>> >>> stdio.h. ?For some reason, this gcc version isn't treating this as a
>> >>> system header and suppressing warnings.
>> >>>
>> >>> It might be possible to work around this by providing an explicit
>> >>> --sysroot argument to ffmpeg's configure. ?Could someone with an
>> >>> affected system please try this?
>> >>>
>> >>
>> >> This is affecting chromium, which uses:
>> >> gcc-sjlj.exe (GCC) 4.2.1-sjlj (mingw32-2)
>> >> a sampling of errors:
>> >>
>> c:\msys\1.0\bin\../lib/gcc/mingw32/4.2.1-sjlj/../../../../include/inttypes.h:259:
>> >> error: no previous prototype for 'imaxabs'
>> >>
>> c:\msys\1.0\bin\../lib/gcc/mingw32/4.2.1-sjlj/../../../../include/math.h:357:
>> >> error: no previous prototype for '__fpclassifyl'
>> >>
>> c:\msys\1.0\bin\../lib/gcc/mingw32/4.2.1-sjlj/../../../../include/stdio.h:372:
>> >> error: no previous prototype for 'getc'
>> >>
>> >> updating to 4.4, it builds. ?But it doesn't run?
>> >
>> > FATE and the autobuilds seem happy about 4.4.2. What version of
>> > binutils and mingw-runtime are you using?
>>
>> Oh, are you using 4.4.0 from mingw.org? I've never gotten it to work,
>> it's full of bugs. It's better if you build your own (or get it from
>> some place like http://www.tdragon.net/recentgcc/ or
>> http://komisar.gin.by/mingw/index.html ).
>>
>
> Ramiro,
> thanks for the links and quick response.
>
> yes, I used 4.4 from mingw.org
> details are here
> svn://chrome-svn/chrome/trunk/deps/third_party/mingw/README.chromium
> which says
>
> binutils-2.17.50-20060824-1.tar.gz
> coreutils-5.97-MSYS-1.0.11-snapshot.tar.bz2
> gcc-core-4.2.1-sjlj-2.tar.gz
> mingwrt-3.15.2-mingw32-dev.tar.gz
> w32api-3.13-mingw32-dev.tar.gz

To use gcc >= 4.3, you need pseudo runtime relocations v2 in both
binutils (>= 2.20) and the mingw-runtime (>= 3.16). The bug is
somewhere in our issue tracker (it's not an FFmpeg bug, but the gcc
bug is referenced there) but I can't find it atm.

> These are only used for ffmpeg, and being open source, contributions
> are welcome.
> I'm not keen to take on more complicated config setup.
>
> I know there is technical merit to 4.4, but at the moment, ffmpeg does not
> build with any officially released compilers?

Probably not. That's not impressive since they're always lacking
behind gcc development.

> I would like to upgrade. ?But my inclination remains to patch ffmpeg to work
> with 4.2 until the next official gcc is made to work.

To patch FFmpeg on the chrome tree? That'd be fine I guess... On
FFmpeg SVN I think we'll only add a note on the documentation, but I
haven't thought this through yet, I'm quite busy.

Ramiro Polla