confused about use of $(noconfig_targets)

[Bernhard Fischer]

On Thu, Mar 02, 2006 at 02:48:32PM -0500, Robert P. J. Day wrote:
>On Thu, 2 Mar 2006, Robin Farine wrote:
>
>> On Thursday March 2 2006 17:32, Robert P. J. Day wrote:
>> > On Thu, 2 Mar 2006, Bernhard Fischer wrote:
>> > > On Thu, Mar 02, 2006 at 10:55:42AM -0500, Robert P. J. Day
>> wrote:
>> > > >> >  in the top-level Rules.mak, there a conditional inclusion
>> > > >> > of the .config file:
>> > > >> >
>> > > >> >  ifeq ($(filter $(noconfig_targets),$(MAKECMDGOALS)),)
>> > > >> >  -include $(top_builddir)/.config
>> > > >> >  endif
>> > >
>> > > If you want to support mixed targets while not breaking
>> > > make-3.80, please submit a patch.
>> >
>> > i would think that all you want to be asking is if there are
>> > *any* targets in $(MAKECMDGOALS) that are *not* in
>> > $(noconfig_targets). wouldn't it be sufficient to just ask:
>> >
>> >   ifneq ($(filter-out $(noconfig_targets),$(MAKECMDGOALS)),)
>> >   -include $(top_builddir)/.config
>> >   endif
>>
>> Yes, this seems to do the right thing.
>
>what's amusing is that that's the directive that's used in the
>top-level Makefile anyway, for exactly the same purpose.

I'm in brain-turned-off-mode in this respect by now, but what's
the difference between
ifeq ($(filter $(noconfig_targets),$(MAKECMDGOALS)),)
and
ifneq ($(filter-out $(noconfig_targets),$(MAKECMDGOALS)),)
again?

The former uses about two ! less than the latter, no?
So what's the jazz this is all about exactly again?

PS: and no, i did neither look at the impl make uses for the four users
nor bench the two pairs against each other..