Re: [PATCH] fix parallel make problem

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 31, 2007, 08:36 UTC
Message-ID: <7v4pig2j91.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20070831081517.GB17637@mellanox.co.il>

"Michael S. Tsirkin" <mst@dev.mellanox.co.il> writes:

Show 16 quoted lines

>> Quoting Junio C Hamano <gitster@pobox.com>:
>> Subject: Re: [PATCH] fix parallel make problem
>> 
>> "Michael S. Tsirkin" <mst@dev.mellanox.co.il> writes:
>> 
>> >> +.PRECIOUS: $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
>> >> +
>> >>  test-%$X: test-%.o $(GITLIBS)
>> >>  	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
>> >
>> > Add a comment here?
>> 
>> I did not see a particular need for that.  What would you say
>> there?
>
> That it's a work-around for make bug.

I would agree it is a make bug to barf like what we saw. Even though we allowed it to treat test-%.o files as intermediate products and allowed them to be removed, it is not a good excuse for make to forget rebuilding them.

But I also happen to think not marking test-%.o as precious was a bug on our side. We would want to keep the build by-product to avoid recompilation, don't we? And this additional line is primarily about fixing that bug, which works the bug around as a side effect.

> So how did this end up in your mail?

Because it is not a format-patch output.

I often run "git diff --stat -p HEAD" from inside MUA in order to get the patch from my work tree, write a proposed commit message, and then reset the change away without committing after sending that message (yes I do not need "git stash" --- gmane and vger are my stashes, Mwhhhaaaa).