[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: question about Generating Prerequisites Automatically
From: |
Lin George |
Subject: |
Re: question about Generating Prerequisites Automatically |
Date: |
Thu, 11 May 2006 05:25:45 -0700 (PDT) |
Thank you Paul!
> An ordinary target is updated if EITHER its
> prerequisites are newer, OR
> the target doesn't exist.
>
> An intermediate target is updated ONLY if its
> prerequisites are newer.
This is exactly what I am looking for. I remembered
that you have mentioned before intermediate file is
useful for increasement build or something. Is that
correct?
I think if it is true, increasement build will suffer
from the issues of intermediate files -- they will not
be remade even if they are "needed", for example, the
intermediate files without any dependencies will
suffer from this issue. I am not sure why increasement
build will choose intermediate file.
regards,
George
--- "Paul D. Smith" <address@hidden> wrote:
> %% Lin George <address@hidden> writes:
>
> >> So, make uses one set of rules to determine
> when to rebuild normal
> >> targets (that are not "intermediate"), and it
> uses a different set
> >> of rules to determine when to rebuild targets
> that ARE
> >> "intermediate".
>
> lg> That is exactly what I mean. :-)
>
> lg> Could you quote the rule which make will use
> to evaluate whether
> lg> an intermediate file is "needed" please? I
> understand your sample,
> lg> but it still seems mysterious to me about a
> general rule about how
> lg> make will evaluate whether or not it is
> "needed". :-)
>
> It's very, very simple; I've already quoted the
> relevant section of the
> manual earlier in this thread. From "Chains of
> Implicit Rules" in the
> GNU make manual:
>
> > The first difference is what happens if the
> intermediate file does
> > not exist. If an ordinary file B does not exist,
> and `make' considers
> > a target that depends on B, it invariably creates
> B and then updates
> > the target from B. But if B is an intermediate
> file, then `make' can
> > leave well enough alone. It won't bother updating
> B, or the ultimate
> > target, unless some prerequisite of B is newer
> than that target or
> > there is some other reason to update that target.
>
> An ordinary target is updated if EITHER its
> prerequisites are newer, OR
> the target doesn't exist.
>
> An intermediate target is updated ONLY if its
> prerequisites are newer.
>
> --
>
-------------------------------------------------------------------------------
> Paul D. Smith <address@hidden> Find some
> GNU make tips at:
> http://www.gnu.org
> http://make.paulandlesley.org
> "Please remain calm...I may be mad, but I am a
> professional." --Mad Scientist
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
- Re: question about Generating Prerequisites Automatically, (continued)
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/04
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/04
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/07
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/07
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/08
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/08
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/09
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/10
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/11
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/11
- Re: question about Generating Prerequisites Automatically,
Lin George <=
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/11
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/11
- Re: question about Generating Prerequisites Automatically, Paul D. Smith, 2006/05/11
- Re: question about Generating Prerequisites Automatically, Lin George, 2006/05/13