[FFmpeg-devel] [PATCH 1/7] avutil: add FF_BAIL_ON_OVERFLOW

[Muhammad Faiz]

On 12/21/16, Andreas Cadhalpun <andreas.cadhalpun at googlemail.com> wrote:
> On 20.12.2016 10:23, Muhammad Faiz wrote:
>> On 12/20/16, Andreas Cadhalpun <andreas.cadhalpun at googlemail.com> wrote:
>>> On 16.12.2016 07:36, Muhammad Faiz wrote:
>>>> On 12/16/16, Andreas Cadhalpun <andreas.cadhalpun at googlemail.com> wrote:
>>>>> Suggested-by: Rodger Combs <rodger.combs at gmail.com>
>>>>> Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
>>>>> ---
>>>>>  libavutil/common.h | 2 ++
>>>>>  1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/libavutil/common.h b/libavutil/common.h
>>>>> index 8142b31..00b7504 100644
>>>>> --- a/libavutil/common.h
>>>>> +++ b/libavutil/common.h
>>>>> @@ -99,6 +99,8 @@
>>>>>  #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a=
>>>>> SWAP_tmp;}while(0)
>>>>>  #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
>>>>>
>>>>> +#define FF_BAIL_ON_OVERFLOW(ctx, x) if (x) {av_log(ctx, AV_LOG_ERROR,
>>>>> "Overflow check failed: " #x"\n"); return AVERROR_INVALIDDATA;}
>>>>
>>>> Where is the overflow check calculation?
>>>
>>> The parameter 'x' is the overflow check used in 'if (x)'.
>>
>> Is it impossible to do something like
>> int ff_mul_check_overflow(int *result, int a, int b)
>> with AVERROR return code on overlow?
>
> Not really, as the point of the macro is to do the error handling,
> which would be needed for a function. Also the function is not
> generic enough, as the type can be int64_t. And then using such
> a function would make the code rather less readable.

Probably provide both ff_mul_ and ff_mul64_ like av_clip/av_clip64