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

From: Masahiro Yamada
Date: Thu Aug 31 2017 - 19:53:19 EST


2017-08-21 18:04 GMT+09:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>:
> 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>
>

Applied to linux-kbuild.