Re: [PATCH] kbuild: gitignore output directory

[Vladimir Kondratiev]

Agree; sending v2

On 2/1/19 6:18 AM, Masahiro Yamada wrote:
> On Wed, Jan 30, 2019 at 8:15 PM Vladimir Kondratiev
> <vladimir.kondratiev@xxxxxxxxxxxxxxx> wrote:
> > When compiling into output directory using O=, many files
> > created under KBUILD_OUTPUT that git considers
> > as new ones; git clients, ex. "git gui" lists it, and it clutters
> > file list making it difficult to see what was really changed
> >
> > Generate .gitignore in output directory that ignores all
> > its content
> >
> > Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@xxxxxxxxxxxxxxx>
> > ---
> >   Makefile | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/Makefile b/Makefile
> > index 141653226f3c..ee66ea28869b 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -483,10 +483,13 @@ PHONY += outputmakefile
> >   # outputmakefile generates a Makefile in the output directory, if using a
> >   # separate output directory. This allows convenient use of make in the
> >   # output directory.
> > +# At the same time when output Makefile generated, generate .gitignore to
> > +# ignore whole output directory
> >   outputmakefile:
> >   ifneq ($(KBUILD_SRC),)
> >          $(Q)ln -fsn $(srctree) source
> >          $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
> > +       echo "# this is build directory, ignore it\n*" > .gitignore
> >   endif
> >
> >   ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
> > --
> > 2.19.1
>
>
> The idea looks OK to me.
> The implementation must be improved.
>
>
> You need to add $(Q) to suppress the annoying command echo.
>
> Also, this patch does not work for all distributions because
> echo "\n"
> is not portable.
>
>
>
> GNU Make runs recipes in /bin/sh (unless SHELL variable is changed),
> but the implementation of /bin/sh depends on distributions.
>
>
> This patch works on Ubuntu etc.
> because /bin/sh is a symbolic link to dash.
>
>
> But, in some distributions,
> /bin/sh is a symbolic link to bash.
>
>
>
> Docker is useful for quick tests of
> various distributions. :)
>
> See the result of  echo "hello\nworld"
>
>
> [Ubuntu]
>
> foo@8ad1275125c5:~$ cat /etc/lsb-release
> DISTRIB_ID=Ubuntu
> DISTRIB_RELEASE=18.10
> DISTRIB_CODENAME=cosmic
> DISTRIB_DESCRIPTION="Ubuntu 18.10"
> foo@8ad1275125c5:~$ ls -l /bin/sh
> lrwxrwxrwx 1 root root 4 Nov 14 23:00 /bin/sh -> dash
> foo@8ad1275125c5:~$ /bin/sh
> $ type echo
> echo is a shell builtin
> $ echo "hello\nworld"
> hello
> world
>
>
>
>
> [CentOS]
>
>
> [foo@c3fbaa4b6f72 ~]$ cat /etc/redhat-release
> CentOS Linux release 7.6.1810 (Core)
> [foo@c3fbaa4b6f72 ~]$ ls -l /bin/sh
> lrwxrwxrwx 1 root root 4 Dec  5 01:36 /bin/sh -> bash
> [foo@c3fbaa4b6f72 ~]$ /bin/sh
> sh-4.2$ type echo
> echo is a shell builtin
> sh-4.2$ echo "hello\nworld"
> hello\nworld
>
>
>
>
>
> On example for workaround might be:
>
> diff --git a/Makefile b/Makefile
> index ee66ea2..010c1c6 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -489,7 +489,7 @@ outputmakefile:
>   ifneq ($(KBUILD_SRC),)
>          $(Q)ln -fsn $(srctree) source
>          $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
> -       echo "# this is build directory, ignore it\n*" > .gitignore
> +       $(Q){ echo "# this is build directory, ignore it"; echo "*"; }
> > .gitignore
>   endif
>
>   ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)