Re: make question (target dependent variable)

[Paul D. Smith]

%% "James" <hslee@ind.alcatel.com> writes:

  j> Thanks. This seesm to work as well.

  j> CFLAGS = -c
  j> CFLAGS += $(shell [ $(foreach f,$(P),$(filter $(f),$@)) ] && echo -g)

Well... yeah.  But... ugh! :-|

You're invoking that shell EVERY TIME you evaluate CFLAGS; and I mean
_in addition to_ the shell that's actually doing the echo.

If you're going to do this you might as well use make's builtin $(if
...)  function instead of calling out to the shell:

    CFLAGS += $(if $(filter $@,$(P)),-g)

Note that (a) you don't need the foreach even the way you wrote it
originally because filter tests _each_ of its arguments against each of
the possibilities; there can be more than one, and (b) if you swap them
(since $@ is only one item) you'll get better performance.


If it were me, I'd still probably use target-specific variables rather
than something like the above.  Seems cleaner to me.

But, either of these is better than using $(shell ...), IMO.

Cheers!

-- 
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 Paul D. Smith <psmith@gnu.org>          Find some GNU make tips at:
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