Re: trouble cleaning the right files ..

[Philip Guenther]

On 6/18/07, sharan basappa <address@hidden> wrote:
...
> Each module make appends its clean target to clean variable as :
> clean     += clean_dir1 .. so eventually clean_all looks like
> clean_all : clean_dir1 clean_dir2
>
> clean_dir1 (for example) rule is :
>
> clean_dir1 :
>         \rm $(local_objs)

The expansion of variables in command rules is always deferred until
the command is run.  That doesn't take place until the makefiles have
been completely parsed.  Ergo, unless you use a target-specific
variable assignment, the above will use the value of local_objs that
was last set during the parsing.  That's what's causing your problem.

There are two solutions:
1) use target-specific variables.  Check out the info pages for the details
   (just search for "target-specific"), but the quick-n-dirty kludge would
  be to add something like:
       clean_dir1: local_objs := $(local_objs)
  near where the clean_dir1 target is defined and similar with other
such targets.

2) instead of using the same variable for all the directories, use a different
   name for each:
       local_objs_dir1 := $(subst .c,.o,$(local_src))
       dir1: $(local_objs_dir1)
       clean_dir1:
               $(RM) $(local_objs_dir1)

  That can be mostly automated using computed names:
       local_objs_$(local_dir) := $(subst .c,.o,$(local_src))
       dir1: $(local_objs_$(local_dir))
       clean_dir1:
               $(RM) $(local_objs_$(subst clean_,,$@))

  ...but that's probably only worthwhile if you factor out that code
into a file
  that each submakefile then included.


Philip Guenther