Activating libssp

[Mel Flynn]

Hi,

for a port, I'm seeing:
#ifdef _FORTIFY_SOURCE
...
#endif

I did a bit of reading (http://wiki.debian.org/Hardening) for example,
searching through /usr/share/mk/* /usr/include/libssp, /usr/src/gnu/libssp.

However, it's not clear to me, where the magic is that pulls in the
libssp library that is in /lib.
Also - it seems to be part of gcc, so does that mean on systems without
gcc, that this library is not available or does clang have a variant?

I do see -fstack-protector is added to CFLAGS by default, so I'm
thinking there's some magic somewhere, but I'm just missing the docs
that tell me "if you add foo to CFLAGS then bar will happen, unless baz".
-- 
Mel