Per-source CFLAGS

[David Schultz]

On Sun, Jun 22, 2003, Bruce Evans wrote:
> On Sat, 21 Jun 2003, David Schultz wrote:
> > ???  You mean we can't add a variable that will normally expand to
> > nil?  This seems like a compatible change, unless you're worried
> > about someone's makefile breaking because they defined
> > CFLAGS_foo.c to mean something else.
> 
> >From POSIX.1-200x-draft7.txt:
> 
> % 23836                 Default Rules
> % 23837                 The default rules for make shall achieve results that are the same as if the following were used.
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> % ...
> % 23864            SINGLE SUFFIX RULES
> % 23865            .c:
> % 23866                    $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<
> 
> This leaves little scope for modifying the default rules.

The results *are* the same with the added ${CFLAGS_$<}, with the
exception of the extra space in the argument list, and I don't
think that's what the POSIX people were thinking.  Is there a
specific problem that this patch would cause for people expecting
standards-compliant make magic (other than a name conflict)?

By the way, is your only complaint that I should not be making
this modification in sys.mk?  I'd be perfectly happy to remove
that part.  I really only care about bsd.lib.mk at the moment, and
the rest was a hasty afterthought for completeness' sake.
To do a complete job without touching sys.mk, it looks like I would
need to duplicate a number of default rules in bsd.prog.mk, though...