Re: [PATCH] kbuild: use $(abspath ...) instead of $(shell cd ... && /bin/pwd)

From: Masahiro Yamada
Date: Mon Aug 21 2017 - 05:05:38 EST


2017-08-21 17:49 GMT+09:00 Thierry Reding <treding@xxxxxxxxxx>:
> 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 <yamada.masahiro@xxxxxxxxxxxxx>
>> ---
>>
>> 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 <treding@xxxxxxxxxx>


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