[FFmpeg-devel] [PATCH] Add -fno-common to PE32 CFLAGS

Baptiste Coudurier baptiste.coudurier
Mon Apr 13 21:48:29 CEST 2009

Hi Ramiro,

On 4/8/2009 6:42 PM, Ramiro Polla wrote:
> Hi,
> Some time ago Art Clarke sent a patch to unconditionally add
> -fno-common to mingw32 builds because of a bug in GCC. Instead of
> applying the patch, the documentation was updated to reflect this bug
> and the workaround.
> The bug details can be found here:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37216
> I finally took some time to investigate what combination of
> gcc+binutils triggers the bug. Just like Brian Dessent mentions in
> comment #6, the bug appears with binutils starting November 2007. The
> gcc version doesn't matter as long as it puts data in .comm. binutils
> 2.18 doesn't show this bug, but it has other shortcomings which make
> it not fit for building FFmpeg.
> With current mingw32 binutils floating around the web, all builds will
> crash at some point in some optimizations (maybe Baptiste can give us
> a sample that really crashes, I haven't seen them yet, but there are
> lots of reports).
> So is it ok to unconditionally include this flag with attached patch
> (and a very descriptive log message) before binutils is fixed?

Yes, please many bug reports on windows because of this, shared libs are
just broken without it.

You might remove it for OS/2 though according to Dave Yeo.

Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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