[FFmpeg-devel] [PATCH] avformat/hlsenc: compiler warning fix

Bodecs Bela bodecsb at vivanet.hu
Mon Jan 20 15:31:07 EET 2020


2020.01.20. 14:25 keltezéssel, Carl Eugen Hoyos írta:
> Am Mo., 20. Jan. 2020 um 14:18 Uhr schrieb Bodecs Bela <bodecsb at vivanet.hu>:
>>
>> 2020.01.20. 14:02 keltezéssel, Carl Eugen Hoyos írta:
>>>>>>>>>> This patch corrects compiler warning about returning possibly uninitialized
>>>>>>>>>> variable in hls_write_header function.
>>>>>>>>>>
>>>>>>>>>> Which compiler warns about this?
>>>>>>>> libavformat/hlsenc.c: In function ‘hls_write_header’:
>>>>>>>> libavformat/hlsenc.c:2174: warning: ‘ret’ may be used uninitialized in
>>>>>>>> this function
>>>>>>> Looks like a false positive, does not warn with newer compilers.
>>>>>> yes and no.
>>>>>>
>>>>>> no, because if hls->nb_varstreams == 0, then for loop body never
>>>>>> executes and so ret does not get any value.
>>>>>>
>>>>>> yes, because there is no chance for hls->nb_varstreams to be zero.
>>>>>>
>>>>>> so, I think setting ret to 0 at its declaration does not do any problem
>>>>>> and logically right.
>>>>> No, update your compiler instead.
>>>> which of my statements did your "No" reference?
>>> Both.
>> Thank you for your help. Maybe due to my poor english, but I really do
>> not see,
>>
>> I really did  test with other compiler and really did not give warning
>> any longer,
>>
>> but it does not help that the ret varaiable remain uninitalized but may
>> be returned.
>>
>> As I know theoretically there is no default value of an int variable.
>>
>> So why the warning did disappear?
> I believe newer compilers detect that hls->nb_varstreams cannot
> be zero.
ok
> Carl Eugen
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".


More information about the ffmpeg-devel mailing list