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

[Måns Rullgård]

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