Re: make question (setting variables)

[James]

Paul D. Smith wrote:
> %% "James" <hslee@ind.alcatel.com> writes:
>
>   j> I have a situation where tens of target dependent variables need to be
>   j> set.
>
>   j> T: AA=aa
>   j> T: BB=bb
>   j> T: CC=cc
>   j> etc.
>
>   j> Is there a compact way of writing these instead of writing
>   j> line-by-line?
>
> No.  But you can use eval to do it in a loop:
>
>   $(foreach V,AA=aa BB=bb CC=cc,$(eval T: $(V)))
>
> Note this will ONLY work with simple variable values (ones that contain
> no whitespace).  Trying to allow values with whitespace using this
> method would be more work than just writing them all out.
>
>
> Alternatively, if your problem is not really so much that you have lots
> of target-dependent variable values you need to set, but rather that you
> have lots of targets that need these variables set, you can loop on the
> target, something like this:
>
>   define SET-VARS
>     $(1): AA=aa
>     $(1): BB=bb
>     $(1): CC=cc
>   endef
>
>   $(foreach T,$(TARGETS),$(eval $(call SET-VARS,$(T))))
>
> You have to write out all the variable settings, yes, but only once
> rather than once per target.
>
> (note this requires at least GNU make 3.80)
>
> --
> -------------------------------------------------------------------------------
>  Paul D. Smith <psmith@gnu.org>          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

Thanks. It was very helpful.
James