Re: [PATCH] kbuild: add more hints about SUBDIRS replacement

[Masahiro Yamada]

On Wed, Jun 26, 2019 at 11:30 PM Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
>
> On Tue, Jun 25, 2019 at 05:51:27PM +0900, Masahiro Yamada wrote:
> > Commit 0126be38d988 ("kbuild: announce removal of SUBDIRS if used")
> > added a hint about the 'SUBDIRS' replacement, but it was not clear
> > enough.
> >
> > Multiple people sent me similar questions, patches.
> >
> >   https://lkml.org/lkml/2019/1/17/456
> >
> > I did not mean to suggest M= for building a subdirectory in the kernel
> > tree.
> >
> > >From the commit 669efc76b317 ("net: hns3: fix compile error"), people
> > already (ab)use M=... to do that because it seems to work to some extent.
> >
> > Documentation/kbuild/kbuild.txt says M= and KBUILD_EXTMOD are used for
> > building external modules.
> >
> > In fact, Kbuild supports the single target '%/' for this purpose, but
> > this may not be noticed much.
> >
> > Kindly add more hints.
> >
> > Makefile:213: ================= WARNING ================
> > Makefile:214: 'SUBDIRS' will be removed after Linux 5.3
> > Makefile:215:
> > Makefile:216: If you are building an individual subdirectory
> > Makefile:217: in the kernel tree, you can do like this:
> > Makefile:218: $ make path/to/dir/you/want/to/build/
> > Makefile:219: (Do not forget the trailing slash)
> > Makefile:220:
> > Makefile:221: If you are building an external module,
> > Makefile:222: Please use 'M=' or 'KBUILD_EXTMOD' instead
> > Makefile:223: ==========================================
> >
> > Suggested-by: Christoph Hellwig <hch@xxxxxx>
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>
> Nice!
>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
>
>         Sam

Applied to linux-kbuild.

-- 
Best Regards
Masahiro Yamada