Re: if function combined with filter or findstring with eval

[Scott Kruger]

Thanks so much for all of the help.  It not only fixed my problem but 
lets me understand what I did wrong and how to develop gmake.

For reference, here is what I came up with to make targets based on
either wildcard search of target names or a findstring of the target
values.  Others might find this useful.

Scott


On 10/20/16 3:39 PM, Philip Guenther wrote:
> On Thu, Oct 20, 2016 at 2:22 PM, Scott Kruger <address@hidden> wrote:
> > I am trying to construct a simple list of variables
> > whose values match certain patterns.  It seems
> > straightforward, but I can't get the righ t
> >
> > The makefile is:
> > ----------
> > RUNTESTS=runex1 runex2 runex3
> > RUNTESTS_ARGS=$(foreach runtest, $(RUNTESTS), $(runtest)_ARGS)
> >
> > ifdef argsearch
> >   FOO:=$(foreach rarg, $(RUNTESTS_ARGS), $(if $(findstring
> > $(argsearch),$(eval $(value rarg))), $(rarg)))
>
> You use := here so this will be evaluated *IMMEDIATELY*, before the
> rest of the Makefile is parsed and therefore before the runex*_ARGS
> variables are set.  Either put those assignments before this
> assignment, or use '=' instead of ':='.
>
> Next, you don't want $(eval).  That's for creating rules or doing
> assignments while in the middle of an expansion.  You don't need that,
> you just need to get the value of the variable whose name is $(rarg).
> You just need two levels of $(), though using $(value $(rarg)) is
> probably best.
>
> So:
>
> FOO=$(foreach rarg,$(RUNTESTS_ARGS),$(if $(findstring
> $(argsearch),$(value $(rarg))),$(rarg)))
>
>
> With that:
> $ gmake argsearch=foo
> > runex1_ARGS runex2_ARGS
> $
>
>
> Philip Guenther

example.make
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