Per-source CFLAGS again

[David Schultz]

The reason I proposed the feature was so that we could compile the
parts of libc that come from a third party (namely, gdtoa) with
different warning flags than the rest of libc.  It was not
committed because someone else proposed a simpler way to get make
to use different flags for gdtoa.

I suppose it wouldn't hurt to commit it it's needed for something
else, but I think Marcel also had some philosophical objections to
the proposal.

On Mon, Sep 20, 2010, David Xu wrote:
> 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