Re: Gnu Make

[Paul D. Smith]

%% Eric Herring <address@hidden> writes:

  eh> I have a problem with calling makefiles within a
  eh> makefile. The toplevel makefile is calling these
  eh> makefile using a for loop. The problem is whenever a
  eh> low level makefile has an error and reports an error,
  eh> the top level make continues with the next make in the
  eh> loop. I need the top level makefile to stop inside the
  eh> for loop when a low level make has an error.

The answer is, don't do it with a for loop.  Use make features!

Instead of this:

  SUBDIRS = foo bar biz baz

  all:
        @for d in $(SUBDIRS); do cd $$d && $(MAKE); done

Do this:

  SUBDIRS = foo bar biz baz

  .PHONY: $(SUBDIRS)

  all: $(SUBDIRS)

  $(SUBDIRS):
        cd $@ && $(MAKE)

This will fail as soon as something breaks under normal use, and will
also work correctly with -k.  And, as an added bonus, it will work
_much_ better with parallel builds should you ever want to try them.  If
you have some dependency between the directories, just declare them as
you normally would; if you can't build directory foo until after
directory bar, add:

  foo: bar

to the makefile.

-- 
-------------------------------------------------------------------------------
 Paul D. Smith <address@hidden>          Find some GNU make tips at:
 http://www.gnu.org                      http://www.paulandlesley.org/gmake/
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist