[FFmpeg-devel] [PATCH] [RFC] libavutil/mem.c: Check return value of posix_memalign

Måns Rullgård mans
Fri Feb 13 17:26:25 CET 2009

Reimar D?ffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> writes:

> On Fri, Feb 13, 2009 at 03:47:23PM +0000, M?ns Rullg?rd wrote:
>> > libavutil/mem.c: In function ?av_malloc?:
>> > libavutil/mem.c:66: warning: ignoring return value of ?posix_memalign?,
>> > declared with attribute warn_unused_result
>> That warning is bogus.  If posix_memalign() fails, memalign() will too
>> since they are likely to be the same function.  We set the pointer to
>> NULL before the call, so if it fails, we return NULL as we're supposed
>> to.
> Well, if you are pedantic you here assume that posix_memalign will not
> modify ptr if it fails (or at least not set it != NULL), but that
> actually does not seem to be guaranteed by POSIX (it doesn't say
> anything about the value of ptr when an error is returned...).

That is indeed the case, and thus your suggestion of explicitly
setting it to NULL makes sense.

M?ns Rullg?rd
mans at mansr.com

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