Re: for sub in $(SUBMAKES); but $(SUBMAKES) is empty

[Paul D. Smith]

%% address@hidden (Alexander Farber) writes:

  af> thanks for your help! But aside from the discussion about the
  af> recursive makefiles (I really don't have a choice at the moment
  af> and have to use them ), is this below supposed to work or not?

This is not a make question; this is a shell question.

Technically, according to the POSIX specs for the behavior of the shell,
the syntax "for i in ; do" is illegal; there must be at least one word
after the "in" and before the end of statement terminator (newline or
";").


So, this:

  af>     linux72:afarber {331} cat Makefile
  af>     SUBMAKES=

  af>     all:
  af>       for i in $(SUBMAKES); do \
  af>               echo $$i; \
  af>       done

may work on some shells but is not portable and not compliant with the
POSIX standard.

But again, this is a shell question not a make question.

  af> Do I really have to modify my makefiles to contain:

  af>     all clean: $(SUBMAKES)
  af>       test -z "$(SUBMAKES)" || for sub in "$(SUBMAKES)"; do \
  af>               $(MAKE) -f $$sub $@; \
  af>       done

  af> This feels so awkward to me. How do others deal with this?

"Others" don't use this model at all.  I much prefer to use make targets
to handle subdirectories; the disadvantages of using a loop like this
are many and serious (IMO).  There is a discussion of this in the GNU
make manual, section on "Phony Targets".

-- 
-------------------------------------------------------------------------------
 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