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

Ramiro Polla ramiro.polla
Thu Apr 9 03:42:33 CEST 2009


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:

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?

Ramiro Polla
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