avutil/attributes: add av_warn_unused_result
authorGanesh Ajjanagadde <gajjanagadde@gmail.com>
Mon, 5 Oct 2015 05:45:12 +0000 (01:45 -0400)
committerMichael Niedermayer <michael@niedermayer.cc>
Mon, 5 Oct 2015 17:30:20 +0000 (19:30 +0200)
commit1d4af04adf99301e21d7364d72f5570f5219083a
treeb9a530f93e8319bb754096b7e1a3be61e1f9b308
parent6f1ccca4ae3b93b6a2a820a7a0e72081ab35767c
avutil/attributes: add av_warn_unused_result

GCC 3.4 introduced an attribute warn_unused_result to warn when a programmer
discards the return value. Applying this judiciously across the codebase can help
in fixing a lot of problems. At a high level, functions which return error codes
should always be checked. More concretely, consider the functions ff_add_format
and the like in avfilter/formats.h. A quick examination shows that a large portion
of libavfilter fails to handle the associated errors, usually AVERROR(ENOMEM).
The above example was where I observed the utility of this, but it should be
useful in many places across the code base.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavutil/attributes.h