[FFmpeg-devel] [PATCH v2] lavc/qsv: suppress code scan complain

[Carl Eugen Hoyos]

2018-05-24 10:35 GMT+02:00, Li, Zhong <zhong.li at intel.com>:
>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
>> Of Carl Eugen Hoyos
>> Sent: Wednesday, May 23, 2018 8:32 PM
>> To: FFmpeg development discussions and patches
>> <ffmpeg-devel at ffmpeg.org>
>> Subject: Re: [FFmpeg-devel] [PATCH v2] lavc/qsv: suppress code scan
>> complain
>>
>> 2018-05-23 12:46 GMT+02:00, Zhong Li <zhong.li at intel.com>:
>> > Suppress the complain "variables 'type' is used but maybe
>> > uninitialized".
>> > ---
>> >  libavcodec/qsv.c | 5 ++++-
>> >  1 file changed, 4 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/libavcodec/qsv.c b/libavcodec/qsv.c index
>> > 45e1c25..3ff4f2c 100644
>> > --- a/libavcodec/qsv.c
>> > +++ b/libavcodec/qsv.c
>> > @@ -31,6 +31,7 @@
>> >  #include "libavutil/hwcontext.h"
>> >  #include "libavutil/hwcontext_qsv.h"
>> >  #include "libavutil/imgutils.h"
>> > +#include "libavutil/avassert.h"
>> >
>> >  #include "avcodec.h"
>> >  #include "qsv_internal.h"
>> > @@ -197,7 +198,7 @@ int ff_qsv_find_surface_idx(QSVFramesContext
>> *ctx,
>> > QSVFrame *frame)
>> >
>> >  enum AVPictureType ff_qsv_map_pictype(int mfx_pic_type)  {
>> > -    enum AVPictureType type;
>> > +    enum AVPictureType type = AV_PICTURE_TYPE_NONE;
>> >      switch (mfx_pic_type & 0x7) {
>> >      case MFX_FRAMETYPE_I:
>> >          if (mfx_pic_type & MFX_FRAMETYPE_S) @@ -214,6 +215,8
>> @@ enum
>> > AVPictureType ff_qsv_map_pictype(int mfx_pic_type)
>> >          else
>> >              type = AV_PICTURE_TYPE_P;
>> >          break;
>> > +    default:
>> > +        av_assert0(0);
>>
>> I didn't test but I would have expected that exactly one of these changes
>> is sufficient to silence the warning, no?
>
> Thanks for review. It is not a compile warning and just found by Coverity
> Scan, I've double-confirmed this patch is useful to suppress the code
> scan complain.

Of course, I understand.

My question was if one of the two changes (ie either the variable
initialization or the assert) isn't enough to suppress the code
scan complain.

Carl Eugen