[FFmpeg-devel] ffmpeg and musl toolchain support
nfxjfg at googlemail.com
Mon Sep 1 16:59:58 CEST 2014
On Mon, 01 Sep 2014 16:14:52 +0200
Jörg Krause <jkrause at posteo.de> wrote:
> When building against musl instead of glibc, compilation fails at
> CC libavutil/error.o
> libavutil/error.c: In function 'av_strerror':
> libavutil/error.c:68:9: error: implicit declaration of function
> 'strerror_r' [-Werror=implicit-function-declaration]
> cc1: some warnings being treated as errors
> make: *** [libavutil/error.o] Error 1
> I tried to find a fix and I am very unsure about the solution.
> I am cross compiling for a linux target. I took a look at
> ffmpeg/configure and added the following line:
> # OS specific
> case $target_os in
> add_cppflags -D_POSIX_SOURCE
> enable dv1394
> With this I can compile ffmpeg successfully.
> What do you think about this solution?
> Why is #undef _GNU_SOURCE in libavutil/error.c defined?
Because there are two strerror_r variants: standard and GNU. They have
different semantics (but same signature). I guess this undef is supposed
to select the POSIX one?
In general, I suspect it might be best to never define _GNU_SOURCE, but
Instead of breaking everything, maybe this would be best to put into
#define _POSIX_C_SOURCE 200809L
More information about the ffmpeg-devel