[FFmpeg-devel] [PATCH] Fix warning about decode_mb_skip (in libavcodec/h264.h)

[Måns Rullgård]

Michael Niedermayer <michaelni at gmx.at> writes:

> On Thu, Jul 01, 2010 at 11:56:32PM +0100, M?ns Rullg?rd wrote:
>> Michael Niedermayer <michaelni at gmx.at> writes:
>> 
>> > On Tue, Jun 29, 2010 at 10:06:12PM -0700, Eli Friedman wrote:
>> >> Patch attached; fixes warning "'decode_mb_skip' defined but not used".
>> >>  As far as I can tell, doesn't have any significant effect on the
>> >> generated code, since the function in question gets inlined either
>> >> way.
>> >
>> > feel free to add av_unused
>> 
>> I'd rather you did one of the following:
>> 
>> 1.  If the intent is to inline the function, mark it inline.
>> 2.  If not, move it to a .c file of your choosing and make it extern.
>> 3.  If only used from one .c file, move it there.
>
> The C language contains (non inline) static functions and they are usefull.
>
> Files that use some templating system will sometimes contain functions that
> are unused in some configurations.
> It is possible that these functions are static.
> It is possible that we want these functions to be static, compare the non
> templated case. By switching from non templated to templated the reasons
> for a function to be static do not suddenly cease to apply.
> There is no reason to forbid this combination. Nor is there any reason to
> throw hours of time at trying to avoid this combiation, this would be
> like forbidding any other arbitrary feature of the language.
> also the function might contain a different implementation in different
> cases of the template making it non static would then not be practical
> without passing its name through a renaming macro.

Templating is all well and good, ...

> and av_unused silences the warning, so we do have a clean solution to get
> rid of the warning.
>
> Also its not much hassle to once in a while run a scipt that checks if
> av_unused marked symbols are used anywhere.
> what does that need? 2 grep commands in a loop?
>
> I really dont understand what problem you have with simply adding av_unused

... but I don't see any templating being done with this function.

-- 
M?ns Rullg?rd
mans at mansr.com