Re: writing a macro to process subdirectories

[Paul D. Smith]

%% "Robert P. J. Day" <address@hidden> writes:

  rpjd> however, reading the make manual, i see an alternative form of
  rpjd> processing SUBDIRS that i prefer, since it supports parallel
  rpjd> processing and subdirectory dependencies:

  rpjd>   SUBDIRS = d1 d2 d3

  rpjd>   .PHONY: subdirs ${SUBDIRS}
  rpjd>   subdirs: ${SUBDIRS}

  rpjd>   ${SUBDIRS}:
  rpjd>           ${MAKE} -C $@

  rpjd>   d1: d2                # potential subdir dependency

  rpjd> but this second form doesn't accommodate a subdirectory target, such
  rpjd> as "configure" or "clean".

I used suffixes for this before, like this:

  SUBDIRS := d1 d2 d3
  TARGETS := clean all configure

  ALLSUBDIRS := $(foreach t,$(TARGETS),$(addsuffix .$(t),$(SUBDIRS)))

  clean:    $(addsuffix .clean,$(SUBDIRS))
  all:      $(addsuffix .all,$(SUBDIRS))
  configure: $(addsuffix .configure,$(SUBDIRS))

  $(ALLSUBDIRS):
        $(MAKE) -C $(patsubst .%,%,$(suffix $@)) $(basename $@)


or whatever.  You can use $(eval ...) to make this much more clean.  And
you'll need to make sure you declare all that stuff (certainly the
directories themselves) .PHONY.

Dependencies are more painful but again you can use loops and eval to
handle it.

-- 
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