Building with seccomp

[Matthew Selsky]

On Sat, May 13, 2017 at 10:10:23PM -0700, Hal Murray via devel wrote:
> 
> If you are missing a library or header, --enable-seccomp gives a warning but 
> doesn't bail.  Should that be changed?
> 
> There are 3 seccomp symbols setup in config.h
>   #define ENABLE_SECCOMP 1 /* Enable seccomp */
>   #define HAVE_SECCOMP_H 1
>   #define HAVE_SECCOMP 1
> 
> Is there any reason for more then one?  It only builds on Linux.  We need 
> both the header and library.

HAVE_SECCOMP can likely be replaced with HAVE_SECCOMP_H in the code.  And we can use ENABLE_SECCOMP or another ctx variable in waf to determine if the user wants us to check for seccomp at all (since we don't check for seccomp by default).  And then we won't set the other variables if ENABLE_SECCOMP is false.

If that makes sense, I can update waf to do this.

Thanks,
-Matt