[MPlayer-dev-eng] fast_memcpy namespace collision

D Richard Felker III dalias at aerifal.cx
Tue Jan 20 00:51:59 CET 2004


On Mon, Jan 19, 2004 at 11:42:18PM +0100, Enrico Weigelt wrote:
> * D Richard Felker III <dalias at aerifal.cx> [2004-01-19 12:06:02 -0500]:
> 
> <snip>
> > Send a bugreport to suse or glibc developers (if it's in stock glibc).
> > Including a function named fast_memcpy violates ansi or posix or
> > something.
> Does it really ?
> What does POSIX say about functions in the base library ?
> Does it specify, that libc may not export other functions than the
> supported ones ?

Nonstandard functions have to be prefixed with _ according to ansi C.
POSIX of course specifies additional functions to be in libc outside
those defined in C, but fast_memcpy is not one of those...

> I personally would prefer renaming the function in the mplayer code.
> If you'd accept the patch, I'd go ahead and replace fast_memcpy by
> _mp_vo_fast_memcpy or something like that.

LOL, this is exactly the opposite of correct. libc _IS_ allowed to
define _mp_vo_fast_memcpy. :)

> BTW: wouldn't it be better (for performance) to code this as an inline 
> function or a macro ? On most platforms it should be less than 5 ops
> (didnt look at the code), so isnt a function call too expensive for
> that job ? ... just a dumb question ...

No, it's fairly large.

Rich




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