Hi, On Wed, Oct 7, 2015 at 8:50 PM, Ganesh Ajjanagadde <gajja...@mit.edu> wrote:
> On Wed, Oct 7, 2015 at 8:21 PM, Michael Niedermayer > <mich...@niedermayer.cc> wrote: > > On Wed, Oct 07, 2015 at 06:22:08PM -0400, Ganesh Ajjanagadde wrote: > >> Commit 6dac8c8327 disabled av_uninit for clang, due to some useless > warnings. > >> The concept of av_uninit is inherently useful though. This patch > silences a > >> bunch of warnings on clang e.g > >> > http://fate.ffmpeg.org/log.cgi?time=20150918181527&log=compile&slot=x86_64-darwin-clang-polly-vectorize-stripmine-3.7 > . > >> Furthermore, it should be useful for general usage of av_uninit in > future. > >> > >> Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com> > >> --- > >> libavutil/attributes.h | 8 ++++++++ > >> 1 file changed, 8 insertions(+) > >> > >> diff --git a/libavutil/attributes.h b/libavutil/attributes.h > >> index 5c6b9de..ceb9e29 100644 > >> --- a/libavutil/attributes.h > >> +++ b/libavutil/attributes.h > >> @@ -147,6 +147,14 @@ > >> > >> #if defined(__GNUC__) && !defined(__INTEL_COMPILER) && > !defined(__clang__) > >> # define av_uninit(x) x=x > >> +#elif defined(__clang__) > >> +#if __has_warning("-Wuninitialized") > >> +# define av_uninit(x) \ > >> + _Pragma("clang diagnostic push") \ > >> + _Pragma("clang diagnostic ignored \"-Wuninitialized\"") \ > >> + x=x \ > >> + _Pragma("clang diagnostic pop") > >> +#endif > > > > this breaks > > make distclean ; ./configure --cc='ccache clang' && make -j12 > > it does not break clang alone and clearing the ccache cache does not > > help > > ccache version 3.1.6 > > > > In file included from libavfilter/af_aecho.c:1: > > libavfilter/af_aecho.c:226:315: error: expected identifier or '(' > > static void echo_samples_dblp(AudioEchoContext *ctx, uint8_t > **delayptrs, uint8_t * const *src, uint8_t **dst, int nb_samples, int > channels) { const double out_gain = ctx->out_gain; const double in_gain = > ctx->in_gain; const int nb_echoes = ctx->nb_echoes; const int max_samples = > ctx->max_samples; int i, j, chan,#pragma clang diagnostic push#pragma clang > diagnostic ignored "-Wuninitialized" index=index#pragma clang diagnostic > pop; ((void)0); for (chan = 0; chan < channels; chan++) { const double *s = > (double *)src[chan]; double *d = (double *)dst[chan]; double *dbuf = > (double *)delayptrs[chan]; index = ctx->delay_index; for (i = 0; i < > nb_samples; i++, s++, d++) { double out, in; in = *s; out = in * in_gain; > for (j = 0; j < nb_echoes; j++) { int ix = index + max_samples - > ctx->samples[j]; ix = (((ix) >= (max_samples)) ? (ix) - (max_samples) : > (ix)); out += dbuf[ix] * ctx->decay[j]; } out *= out_gain; *d = > av_clipd_c(out, -1.0, 1.0); dbuf[index] = in; index = (((index + 1) >= > (max_samples)) ? (index + 1) - (max_samples) : (index + 1)); } } > ctx->delay_index = index; } > > > > > > ^ > > > > [...] > > ccache and clang have some weird interaction issues -for instance a > lot of -Warray-bounds are triggered for glibc functions like strcmp. I > vaguely recall some suggestion to use an environment variable to avoid > the breakage: > http://petereisentraut.blogspot.com/2011/09/ccache-and-clang-part-2.html > > Anyway, this sounds like it needs to be fixed upstream with clang or > ccache or possibly both. I agree, and am a little sad that the patch can't go in yet. Would you mind filing a bug with ccache? According to that blog post, they (ccache devs) do look at their bug tracker, and we have all information necessary to make a relatively trivial test case for them (just the av_uninit define and a one-line main() function that uses av_uninit should do the trick). Ronald _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
