Re: Odd rule issue

[Oleksandr Gavenko]

On 10.12.2010 0:31, David Boyce wrote:
> On Thu, Dec 9, 2010 at 6:26 AM, AdamWainwright<address@hidden>  wrote:
> > -------------------------------------------------
> > PROGS=../xxx
> >
> > $(PROGS): $(addsuffix .y, $(@F))
> >         cp $(@F).y $@
> > -------------------------------------------------
> >
> > Initial run copies file 'xxx.y' to 'xxx'.  If 'xxx.y' is updated then the
> > rule does not equate to 'true' (because the file 'xxx' doesn't exist) and
> > actions taken.  Using debug I find it isn't even considering the
> > dependencies of the addsuffix() and states that the file doesn't need to be
> > updated.  I feel there is some error in my logic here but I can't put my
> > finger on it.
>
> One error in your logic is documented at
> http://www.gnu.org/software/make/manual/make.html#Automatic-Variables:
> "It's very important that you recognize the limited scope in which
> automatic variable values are available: they only have values within
> the recipe." Since $@ and its variant $(@F) are automatic variables,
> they cannot be used in the top (target: prereq) line.
And also you can see doc about .SECONDEXPANSION.

But stop!

How about "Pattern Rules"?

../%: %.y
        cp ...

or if PROGS count is few (you mention only one) write:

../prog1: prog1.y
        cp ...
../prog2: prog2.y
        cp ...

--
С уважением, Александр Гавенко.