This patch:
http://patch-tracker.debian.org/patch/series/view/exim4/4.80-2/30_dontoverridecflags.dpatch
causes Exim to conditionally set CFLAGS in OS/Makefile-Linux using ?=
syntax.
That seems eminently sane to me. Does anyone know a reason to not
apply this to base?
I think this is rather old syntax, so likely to be supported by even the
creakiest of Linux systems. Anyone know otherwise? We use it currently
in GNU and NetBSD systems.
I just double-checked, and it looks like only '=' assignment of macros
is guaranteed by POSIX, which matches my creaky recollection. I know
the BSD systems have supported '?=' for a long time, and I know Gnu make
has supported ':=' for a long time; I'm just unclear on the age of ?=
support in GNU Mkae.
Thanks,
-Phil
