Kbuild conventionally uses $(shell cd ... && /bin/pwd) idiom to get
the absolute path of the directory because GNU Make 3.80, the minimal
supported version at that time, did not support $(abspath ...) or
$(realpath ...).
Commit 37d69ee30808 ("docs: bump minimal GNU Make version to 3.81")
dropped the GNU Make 3.80 support, so we are now allowed to use those
make-builtin helpers.
This conversion will provide better portability without relying on
the pwd command or its location /bin/pwd.
I am intentionally using $(realpath ...) instead $(abspath ...) in
some places. The difference between the two is $(realpath ...)
returns an empty string if the given path does not exist. It is
convenient in places where we need to error-out if the makefile fails
to create an output directory.
Signed-off-by: Masahiro Yamada <[email protected]>
---
Makefile | 12 ++++++------
scripts/gdb/linux/Makefile | 2 +-
tools/power/cpupower/Makefile | 2 +-
tools/scripts/Makefile.include | 6 +++---
4 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/Makefile b/Makefile
index 90da7bdc3f45..dfb6c88ea859 100644
--- a/Makefile
+++ b/Makefile
@@ -130,8 +130,8 @@ endif
ifneq ($(KBUILD_OUTPUT),)
# check that the output directory actually exists
saved-output := $(KBUILD_OUTPUT)
-KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
- && /bin/pwd)
+$(shell [ -d $(KBUILD_OUTPUT) ] || mkdir -p $(KBUILD_OUTPUT))
+KBUILD_OUTPUT := $(realpath $(KBUILD_OUTPUT))
$(if $(KBUILD_OUTPUT),, \
$(error failed to create output directory "$(saved-output)"))
@@ -978,7 +978,7 @@ ifdef CONFIG_HEADERS_CHECK
$(Q)$(MAKE) -f $(srctree)/Makefile headers_check
endif
ifdef CONFIG_GDB_SCRIPTS
- $(Q)ln -fsn `cd $(srctree) && /bin/pwd`/scripts/gdb/vmlinux-gdb.py
+ $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
endif
ifdef CONFIG_TRIM_UNUSED_KSYMS
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
@@ -1237,7 +1237,7 @@ _modinst_:
@rm -rf $(MODLIB)/kernel
@rm -f $(MODLIB)/source
@mkdir -p $(MODLIB)/kernel
- @ln -s `cd $(srctree) && /bin/pwd` $(MODLIB)/source
+ @ln -s $(abspath $(srctree)) $(MODLIB)/source
@if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
rm -f $(MODLIB)/build ; \
ln -s $(CURDIR) $(MODLIB)/build ; \
@@ -1629,11 +1629,11 @@ image_name:
# Clear a bunch of variables before executing the submake
tools/: FORCE
$(Q)mkdir -p $(objtree)/tools
- $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/
+ $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
tools/%: FORCE
$(Q)mkdir -p $(objtree)/tools
- $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(shell cd $(objtree) && /bin/pwd) subdir=tools -C $(src)/tools/ $*
+ $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/ $*
# Single targets
# ---------------------------------------------------------------------------
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile
index 8b00031f5349..ab3cfe727a4e 100644
--- a/scripts/gdb/linux/Makefile
+++ b/scripts/gdb/linux/Makefile
@@ -1,6 +1,6 @@
always := gdb-scripts
-SRCTREE := $(shell cd $(srctree) && /bin/pwd)
+SRCTREE := $(abspath $(srctree))
$(obj)/gdb-scripts:
ifneq ($(KBUILD_SRC),)
diff --git a/tools/power/cpupower/Makefile b/tools/power/cpupower/Makefile
index d6e1c02ddcfe..4c5a481a850c 100644
--- a/tools/power/cpupower/Makefile
+++ b/tools/power/cpupower/Makefile
@@ -26,7 +26,7 @@ endif
ifneq ($(OUTPUT),)
# check that the output directory actually exists
-OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
+OUTDIR := $(realpath $(OUTPUT))
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index ccad8ce925e4..57a850978cef 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -1,7 +1,7 @@
ifneq ($(O),)
ifeq ($(origin O), command line)
- dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
- ABSOLUTE_O := $(shell cd $(O) ; pwd)
+ ABSOLUTE_O := $(realpath $(O))
+ dummy := $(if $(ABSOLUTE_O),,$(error O=$(O) does not exist))
OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
COMMAND_O := O=$(ABSOLUTE_O)
ifeq ($(objtree),)
@@ -12,7 +12,7 @@ endif
# check that the output directory actually exists
ifneq ($(OUTPUT),)
-OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
+OUTDIR := $(realpath $(OUTPUT))
$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
endif
--
2.7.4
On Sun, Aug 20, 2017 at 03:04:11PM +0900, Masahiro Yamada wrote:
> Kbuild conventionally uses $(shell cd ... && /bin/pwd) idiom to get
> the absolute path of the directory because GNU Make 3.80, the minimal
> supported version at that time, did not support $(abspath ...) or
> $(realpath ...).
>
> Commit 37d69ee30808 ("docs: bump minimal GNU Make version to 3.81")
> dropped the GNU Make 3.80 support, so we are now allowed to use those
> make-builtin helpers.
>
> This conversion will provide better portability without relying on
> the pwd command or its location /bin/pwd.
>
> I am intentionally using $(realpath ...) instead $(abspath ...) in
> some places. The difference between the two is $(realpath ...)
> returns an empty string if the given path does not exist. It is
> convenient in places where we need to error-out if the makefile fails
> to create an output directory.
>
> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> Makefile | 12 ++++++------
> scripts/gdb/linux/Makefile | 2 +-
> tools/power/cpupower/Makefile | 2 +-
> tools/scripts/Makefile.include | 6 +++---
> 4 files changed, 11 insertions(+), 11 deletions(-)
This looks very similar to a patch I had written a long time ago:
Acked-by: Thierry Reding <[email protected]>
2017-08-21 17:49 GMT+09:00 Thierry Reding <[email protected]>:
> On Sun, Aug 20, 2017 at 03:04:11PM +0900, Masahiro Yamada wrote:
>> Kbuild conventionally uses $(shell cd ... && /bin/pwd) idiom to get
>> the absolute path of the directory because GNU Make 3.80, the minimal
>> supported version at that time, did not support $(abspath ...) or
>> $(realpath ...).
>>
>> Commit 37d69ee30808 ("docs: bump minimal GNU Make version to 3.81")
>> dropped the GNU Make 3.80 support, so we are now allowed to use those
>> make-builtin helpers.
>>
>> This conversion will provide better portability without relying on
>> the pwd command or its location /bin/pwd.
>>
>> I am intentionally using $(realpath ...) instead $(abspath ...) in
>> some places. The difference between the two is $(realpath ...)
>> returns an empty string if the given path does not exist. It is
>> convenient in places where we need to error-out if the makefile fails
>> to create an output directory.
>>
>> Signed-off-by: Masahiro Yamada <[email protected]>
>> ---
>>
>> Makefile | 12 ++++++------
>> scripts/gdb/linux/Makefile | 2 +-
>> tools/power/cpupower/Makefile | 2 +-
>> tools/scripts/Makefile.include | 6 +++---
>> 4 files changed, 11 insertions(+), 11 deletions(-)
>
> This looks very similar to a patch I had written a long time ago:
>
> Acked-by: Thierry Reding <[email protected]>
Yup.
Three month ago, I sent a reminder to you,
but I did not get a response.
https://lkml.org/lkml/2017/5/18/1370
This time, Bjorn sent a patch to replace /bin/pwd with pwd.
I asked him to use $(abspath ...) / $(realpath ...),
but he did not like to do it.
https://patchwork.kernel.org/patch/9859591/
So, I am doing it by myself.
--
Best Regards
Masahiro Yamada
2017-08-21 18:04 GMT+09:00 Masahiro Yamada <[email protected]>:
> 2017-08-21 17:49 GMT+09:00 Thierry Reding <[email protected]>:
>> On Sun, Aug 20, 2017 at 03:04:11PM +0900, Masahiro Yamada wrote:
>>> Kbuild conventionally uses $(shell cd ... && /bin/pwd) idiom to get
>>> the absolute path of the directory because GNU Make 3.80, the minimal
>>> supported version at that time, did not support $(abspath ...) or
>>> $(realpath ...).
>>>
>>> Commit 37d69ee30808 ("docs: bump minimal GNU Make version to 3.81")
>>> dropped the GNU Make 3.80 support, so we are now allowed to use those
>>> make-builtin helpers.
>>>
>>> This conversion will provide better portability without relying on
>>> the pwd command or its location /bin/pwd.
>>>
>>> I am intentionally using $(realpath ...) instead $(abspath ...) in
>>> some places. The difference between the two is $(realpath ...)
>>> returns an empty string if the given path does not exist. It is
>>> convenient in places where we need to error-out if the makefile fails
>>> to create an output directory.
>>>
>>> Signed-off-by: Masahiro Yamada <[email protected]>
>
Applied to linux-kbuild.