[PATCH RFC] kbuild: improvement in Makefile.modbuiltin

From: Cao jin
Date: Sat Nov 18 2017 - 06:25:43 EST


Drop unnecessary "__subdir-Y" and `cat /dev/null`

Signed-off-by: Cao jin <caoj.fnst@xxxxxxxxxxxxxx>
---
Don't know why they exist, but a simple build is fine without them
in my test

scripts/Makefile.modbuiltin | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin
index a763b4775d06..cbb1e3dc1ef9 100644
--- a/scripts/Makefile.modbuiltin
+++ b/scripts/Makefile.modbuiltin
@@ -26,8 +26,7 @@ kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbui
include $(kbuild-file)

include scripts/Makefile.lib
-__subdir-Y := $(patsubst %/,%,$(filter %/, $(obj-Y)))
-subdir-Y += $(__subdir-Y)
+subdir-Y := $(patsubst %/,%,$(filter %/, $(obj-Y)))
subdir-ym := $(sort $(subdir-y) $(subdir-Y) $(subdir-m))
subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
obj-Y := $(addprefix $(obj)/,$(obj-Y))
@@ -41,7 +40,7 @@ __modbuiltin: $(modbuiltin-target) $(subdir-ym)

$(modbuiltin-target): $(subdir-ym) FORCE
$(Q)(for m in $(modbuiltin-mods); do echo kernel/$$m; done; \
- cat /dev/null $(modbuiltin-subdirs)) > $@
+ cat $(modbuiltin-subdirs)) > $@

PHONY += FORCE

--
2.13.6