[FFmpeg-devel] [PATCH]Only build ffserver if SA_RESTART is defined

[Reimar Döffinger]

On Sat, Jul 13, 2013 at 02:34:27PM -0400, Derek Buitenhuis wrote:
> On 7/13/2013 6:28 AM, Nicolas George wrote:
> > I suppose Derek missed
> > that "42;" is a valid C statement, just a completely useless one; some
> > compilers will issue a warning about it, but warnings in configure are not a
> > problem.
> 
> Nope, but as a convention, we check CPP things with check_cpp_condition.
> 
> It is interesting that it the spec states "need not be usable in
> #if preprocessing directives" though. Nice find.

Is it relevant though? I think if anything we should be using
#ifdef, and I don't see how any macro could be broken with that.
I suspect what they were thinking of that you could do something like
enum {... SA_RESTART};
#define SA_RESTART SA_RESTART

So you couldn't do
#if SA_RESTART == 42
but
#ifdef SA_RESTART
would of course still work fine.