[FFmpeg-devel] [PATCH] libavcodec/wmavoice.c: localvariablepowmight mask pow function

[Reimar Döffinger]

On Mon, Jul 26, 2010 at 01:52:44PM +0200, Axel Holzinger wrote:
> Now, if you are right that would be illegal for a standard lib header
> (not only for C99, but also for C89, which MS claims to be compatible
> with).

I can't imagine they are claiming that, they aren't compatible with an C
standard version at all, for example due to making near and far keywords.
For all I know, Microsoft never had, never intended to, and probably never
will have any standard-compilant C compiler. They only care about C++.

> On my Kubuntu 9.04 in math.h I find
> 
> #  define isgreater(x, y) \
>   (__extension__
>    ({ __typeof__(x) __x = (x); __typeof(y) __y = (y);
>       !isunordered (__x, __y) && __x > __y; }))
> 
> This masks a local variable isunordered.

Since isunordered is a macro there is no problem there.
There is no naming clash between a variable and a function-like
macro, only a variable and a function with the same name
causes problems.