[FFmpeg-devel] [PATCHv2] avutil/attributes: extend av_uninit to clang

[Ganesh Ajjanagadde]

On Thu, Oct 8, 2015 at 3:11 AM, Nicolas George <george at nsup.org> wrote:
> Le sextidi 16 vendémiaire, an CCXXIV, Ganesh Ajjanagadde a écrit :
>> Anyway, it seems to me that for whatever reason short circuit
>> evaluation is not respected by the GCC preprocessor (I lack the energy
>> or interest to investigate why, it seems ridiculous to me):
>> https://bugs.webkit.org/show_bug.cgi?id=133785
>
> Do not believe everything you read from apple developers, this statement is
> completely wrong.
>
> Short-circuit evaluation works with the preprocessor, you can check with
> this for example:
>
> #if defined(x) && x
>
> What does not work is a malformed expression:
>
> #if defined(x) && x(42)
>
> ... because x(42), if x is not defined, expands to 0(42), which is not
> syntactically valid as an expression.

Thanks for the clarification. I was still expecting slightly more from
the preprocessor - I assumed if x is not defined, it does not even
bother parsing the remainder of the line, and this was the sense of
short circuit evaluation that I expected. Thinking it over, there are
other reasons why it might want a valid expression throughout the
line.

>
> Regards,
>
> --
>   Nicolas George
>
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