Per-source CFLAGS again

[David Xu]

I found a topic about per-source CFLAGS,
http://lists.freebsd.org/pipermail/freebsd-arch/2003-June/000906.html

and it seems the patch was never committed, why ?
I feel it is useful because I want to compile those files which
have cancellation points with compiler flag -fexceptions, for example,
POSIX semaphore cancellation point in libc must be compiled with
-fexceptions to support stack unwinding.

Regards,
David Xu