kbuild: split out *.mod out of {single,multi}-used-m rules

Currently, *.mod is created as a side-effect of obj-m.

Split out *.mod as a dedicated build rule, which allows to unify
the %.c -> %.o rule, and remove the single-used-m rule.

This also makes the incremental build of allmodconfig faster because
it saves $(NM) invocation when there is no change in the module.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Masahiro Yamada 2019-07-17 15:18:00 +09:00
parent 30527cefb3
commit 9f69a496f1

View File

@ -67,8 +67,10 @@ ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
modorder-target := $(obj)/modules.order
endif
mod-targets := $(patsubst %.o, %.mod, $(obj-m))
__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
$(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
$(if $(KBUILD_MODULES),$(obj-m) $(mod-targets) $(modorder-target)) \
$(subdir-ym) $(always)
@:
@ -261,7 +263,7 @@ endef
# List module undefined symbols (or empty line if not enabled)
ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo
cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo
else
cmd_undef_syms = echo
endif
@ -271,11 +273,15 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
@{ echo $@; \
$(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
cmd_mod = { \
echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
$(cmd_undef_syms); \
} > $@
$(obj)/%.mod: $(obj)/%.o FORCE
$(call if_changed,mod)
targets += $(mod-targets)
quiet_cmd_cc_lst_c = MKLST $@
cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
@ -456,8 +462,6 @@ quiet_cmd_link_multi-m = LD [M] $@
$(multi-used-m): FORCE
$(call if_changed,link_multi-m)
@{ echo $(filter %.o,$^); \
$(cmd_undef_syms); } > $(patsubst %.o,%.mod,$@)
$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
targets += $(multi-used-m)