Re: GNU make suggestion: did the dependency really change?

[Henning Makholm]

Scripsit "Paul D. Smith" <address@hidden>
> %% Henning Makholm <address@hidden> writes:

>   hm> I would really like to have a make tool that could discover that
>   hm> mod2.ui did not actually change when we rebuilt it.

> One way is to build that into your process, rather than trying to change
> GNU make.

>   %.ui : %.sig
>             @[ -f $@ ] && mv $@ address@hidden
>             mosmlc -c $<
>             @cmp -s $@ address@hidden && mv address@hidden $@

Hm (checks it..) it works. Amazing. Where should I have looked for
that behavior in the documentation?

> It's true that this doesn't update the timestamps of the "unchanged"
> files, so that this step will be repeated in the future.

Yes - and I really like the possibility to simply look for

$ make
make: Nothing to be done for `all'
$

to check that everything is right, e.g. just before a cvs commit.
But I suppose that doing

$ make && make -t

will be a sufficient solution (at least sufficient enough to keep me
from hacking around in the source for make).

> Instead, the fundamental problem should be addressed: the problem
> I'm thinking of is the stateless nature of make.  Make needs the
> ability to remember state from previous builds

This would be a really good idea - it would probably solve some of my
other little itches too - but is not something I can spare the time to
attack.

-- 
Henning Makholm                            "I, madam, am the Archchancellor!
                                       And I happen to run this University!"