[PATCH] let kbuild mkdir for dir/file.o

From: ååå
Date: Sun Jun 30 2013 - 05:11:10 EST


When add a obj with dir to obj-y, like this

obj-y += dir/file.o

The $(obj)/dir not created, this patch fix this.

When try to add a file(which in a subdir) to my board's obj-y, the build
progress crashed.

For example, I use at91rm9200ek board, and in kernel dir run:

mkdir objtree
make O=objtree at91rm9200_defconfig
mkdir arch/arm/mach-at91/dir
touch arch/arm/mach-at91/dir/file.c

and edit arch/arm/mach-at91/dir/file.c to add some code.
then edit arch/arm/mach-at91/Makefile, change the following line:

obj-$(CONFIG_MACH_AT91RM9200EK) += board-rm9200ek.o

to:

obj-$(CONFIG_MACH_AT91RM9200EK) += board-rm9200ek.o dir/file.o

Now build it:

make O=objtree

Then the error appears:
...
CC arch/arm/mach-at91/board-rm9200dk.o
CC arch/arm/mach-at91/board-rm9200ek.o
CC arch/arm/mach-at91/dir/file.o
linux-2.6/arch/arm/mach-at91/dir/file.c:5:
fatal error: opening dependency file
arch/arm/mach-at91/dir/.file.o.d: No such file or directory

Check the objtree:
LANG=en ls objtree/arch/arm/mach-at91/dir
ls: cannot access objtree/arch/arm/mach-at91/dir: No such file or directory

It's apparently that the target dir not created for file.o

Check kbuild source code. It seems that kbuild create dirs for that in
$(obj-dirs). But if the dir need not to create a built-in.o, It should
never in $(obj-dirs).

So I make this patch to make sure It in $(obj-dirs)

this bug caused by commit
f5fb976520a53f45f8bbf2e851f16b3b5558d485
---
scripts/Makefile.lib | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 51bb3de..cddd2c9 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -63,7 +63,7 @@ multi-objs := $(multi-objs-y) $(multi-objs-m)
subdir-obj-y := $(filter %/built-in.o, $(obj-y))

# $(obj-dirs) is a list of directories that contain object files
-obj-dirs := $(dir $(multi-objs) $(subdir-obj-y))
+obj-dirs := $(dir $(multi-objs) $(obj-y))

# Replace multi-part objects by their individual parts, look at local dir only
real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y)
--
1.7.9.5

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