kbuild: handle multi-objs dependency appropriately
authorMasahiro Yamada <yamada.m@jp.panasonic.com>
Tue, 19 Aug 2014 07:34:20 +0000 (16:34 +0900)
committerMichal Marek <mmarek@suse.cz>
Tue, 19 Aug 2014 08:26:19 +0000 (10:26 +0200)
commitc8589d1e9e01debdb4f574afe7c585714353ad79
treed97e91953904fe8db17367b8323410f2003a4faa
parent7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9
kbuild: handle multi-objs dependency appropriately

The comment in scripts/Makefile.build says as follows:

  We would rather have a list of rules like
        foo.o: $(foo-objs)
  but that's not so easy, so we rather make all composite objects depend
  on the set of all their parts

This commit makes it possible!

For example, assume a Makefile like this

  obj-m = foo.o bar.o
  foo-objs := foo1.o foo2.o
  bar-objs := bar1.o bar2.o

Without this patch, foo.o depends on all of
foo1.o foo2.o bar1.o bar2.o.
It looks funny that foo.o is regenerated when bar1.c is updated.

Now we can handle the dependency of foo.o and bar.o separately.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
scripts/Makefile.build
scripts/Makefile.lib