Commit c8589d1e authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Michal Marek
Browse files

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: default avatarMasahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
parent 7d1311b9

scripts/Makefile.build

+4 −6
Original line number Diff line number Diff line
@@ -382,16 +382,14 @@ cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalys 
quiet_cmd_link_multi-m = LD [M]  $@

cmd_link_multi-m = $(cmd_link_multi-y)



# 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

$(multi-used-y) : %.o: $(multi-objs-y) FORCE

$(multi-used-y): FORCE

	$(call if_changed,link_multi-y)

$(call multi_depend, $(multi-used-y), .o, -objs -y)



$(multi-used-m) : %.o: $(multi-objs-m) FORCE

$(multi-used-m): FORCE

	$(call if_changed,link_multi-m)

	@{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)

$(call multi_depend, $(multi-used-m), .o, -objs -y)



targets += $(multi-used-y) $(multi-used-m)

scripts/Makefile.lib

+9 −0
Original line number Diff line number Diff line
@@ -159,6 +159,15 @@ dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \ 
modname-multi = $(sort $(foreach m,$(multi-used),\

		$(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))



# Useful for describing the dependency of composite objects

# Usage:

#   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)

define multi_depend

$(foreach m, $(notdir $1), \

	$(eval $(obj)/$m: \

	$(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))

endef



ifdef REGENERATE_PARSERS



# GPERF

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