| Message ID | 20190625085127.9446-1-yamada.masahiro@socionext.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: add more hints about SUBDIRS replacement | expand |
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@lst.de> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Nice! Acked-by: Sam Ravnborg <sam@ravnborg.org> Sam
On Wed, Jun 26, 2019 at 11:30 PM Sam Ravnborg <sam@ravnborg.org> 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@lst.de> > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > > Nice! > > Acked-by: Sam Ravnborg <sam@ravnborg.org> > > Sam Applied to linux-kbuild.
diff --git a/Makefile b/Makefile index 7a7c17eb0cbf..823a39d940c6 100644 --- a/Makefile +++ b/Makefile @@ -212,6 +212,13 @@ endif ifdef SUBDIRS $(warning ================= WARNING ================) $(warning 'SUBDIRS' will be removed after Linux 5.3) + $(warning ) + $(warning If you are building an individual subdirectory) + $(warning in the kernel tree, you can do like this:) + $(warning $$ make path/to/dir/you/want/to/build/) + $(warning (Do not forget the trailing slash)) + $(warning ) + $(warning If you are building an external module,) $(warning Please use 'M=' or 'KBUILD_EXTMOD' instead) $(warning ==========================================) KBUILD_EXTMOD ?= $(SUBDIRS)
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@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Makefile | 7 +++++++ 1 file changed, 7 insertions(+)