Re: [PATCH] scripts: Fallback to KBUILD_OUTPUT if O is not specified

[Wangnan (F)]

On 2016/4/8 22:58, Arnaldo Carvalho de Melo wrote:
> Em Fri, Apr 08, 2016 at 11:14:09AM +0200, Thierry Reding escreveu:
> > From: Thierry Reding <treding@xxxxxxxxxx>
> >
> > The KBUILD_OUTPUT environment can be used to set the build directory as
> > an alternative to passing the O variable on the command-line. This works
> > with regular kernel builds, so it's surprising if it doesn't work within
> > the tools/scripts directory.
> >
> > Allow KBUILD_OUTPUT if O is not specified on the command-line to avoid
> > any surprises.
> I think this is fine, Jiri, Wang?

The idea is fine, but we should be very careful when touching Makefile
to avoid breaking build-test like this:

 # export KBUILD_OUTPUT=/tmp/xxxxx
 #  ./tests/perf-targz-src-pkg .
   PERF_VERSION = 4.5.g337b7b
 ls: cannot access perf-*.tar.gz: No such file or directory
 tar: -C: Cannot open: No such file or directory
 tar: Error is not recoverable: exiting now
 make: *** /tmp/tmp.q4egWrFd3L/perf*/tools/perf: No such file or 
directory.  Stop

Moreover, in the above case, the output directory should be

 /tmp/xxxxx

or

 /tmp/xxxxx/tools/perf ?

Since kernel build output things to /tmp/xxxxx, I think we'd better
output to /tmp/xxxxx/tools/perf.

Thank you.

> - Arnaldo
>   
> > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> > ---
> > Hi Arnaldo,
> >
> > I'm not sure if you're the right person to send this to. There was noone
> > reported by scripts/get_maintainer.pl, but it looks like you ended up
> > applying most of the patches to this file lately, which kinda makes you
> > the de facto maintainer =).
> >
> > Thierry
> >
> >   tools/scripts/Makefile.include | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
> > index 8abbef164b4e..5467da41dc72 100644
> > --- a/tools/scripts/Makefile.include
> > +++ b/tools/scripts/Makefile.include
> > @@ -8,6 +8,10 @@ ifeq ($(objtree),)
> >   	objtree := $(O)
> >   endif
> >   endif
> > +else
> > +ifneq ($(KBUILD_OUTPUT),)
> > +	OUTPUT := $(KBUILD_OUTPUT)/$(if $(subdir),$(subdir)/)
> > +endif
> >   endif
> >   
> >   # check that the output directory actually exists
> > --
> > 2.8.0