Re: make -C tools clean failure on older systems

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, May 14, 2015 at 09:39:43AM -0600, Shuah Khan escreveu:
> On 05/14/2015 09:12 AM, Arnaldo Carvalho de Melo wrote:
> > Hi,
> > 
> > 	In:
> > 
> >  -------------
> > commit 67d8712dcc70aa16d8e14a52eb73870e3cbddfc2
> > Author: Shuah Khan <shuahkh@osg.samsung.com>
> > Date:   Wed Mar 18 11:57:39 2015 -0600
> > 
> >     selftests: Fix build failures when invoked from kselftest target
> > 
> >  -------------
> > 
> > You cleaned two variables using different methods, any reason for that?
> > 
> > I asked because the 'undefine' method causes it to fail in older
> > systems:
> 
> The reason for this change is some tests fail to build when invoked
> from the main Makefile level. The commit log explains the change:

I saw it

> > +++ b/tools/testing/selftests/Makefile
> > @@ -27,7 +27,7 @@ TARGETS_HOTPLUG += memory-hotplug
> >  # Makefile to avoid test build failures when test
> >  # Makefile doesn't have explicit build rules.
> >  ifeq (1,$(MAKELEVEL))
> > -undefine LDFLAGS
> > +override LDFLAGS =
> >  override MAKEFLAGS =
> >  endif
> 
> I recall testing with override and remember it to not work. If you would

bummer, then its not that easy, I thought it was an oversight, but if
you tested it and it didn't work, nevermind, no need, I guess, to
support older systems if it requires more, non trivial, work.

> like experiment with it, feel free to send a patch with that change. My
> make version is very new:
> 
> make --version
> GNU Make 4.0
> Built for x86_64-pc-linux-gnu
> 
> You have to run make kselftest from the main kernel Makefile to see
> the build failures that undefine LDFLAGS fixed.
> 
> thanks,
> -- Shuah
> 
> 
> 
> -- 
> Shuah Khan
> Sr. Linux Kernel Developer
> Open Source Innovation Group
> Samsung Research America (Silicon Valley)
> shuahkh@osg.samsung.com | (970) 217-8978