Re: [2.6 patch] run all userspace headers through unifdef

[Sam Ravnborg <sam@ravnborg.org>]

On Wed, May 21, 2008 at 11:22:43PM -0700, Andrew Morton wrote:
> On Wed, 21 May 2008 20:41:43 +0300 Adrian Bunk <bunk@kernel.org> wrote:
> 
> > Facts:
> > - installing userspace headers is nothing that is required as part of a 
> >   normal kernel build
> > - unifdef is relatively fast
> > - there are sometimes patches moving headers from header-y to unifdef-y 
> >   or the other way round
> > 
> > Instead of constantly seeing headers moving between header-y and 
> > unifdef-y this patch removes unifdef-y and runs all userspace headers 
> > through unifdef.
> > 
> > It also contains some unrelated sorting corrections in the Kbuild files 
> > since I used GNU sort for the semi-automatic conversion of the Kbuild 
> > files.
> > 
> > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> > 
> > ---
> > 
> >  include/asm-alpha/Kbuild              |   11 
> >  include/asm-arm/Kbuild                |    2 
> >  include/asm-cris/Kbuild               |    5 
> >  include/asm-frv/Kbuild                |    5 
> >  include/asm-generic/Kbuild            |    9 
> >  include/asm-generic/Kbuild.asm        |   61 +--
> >  include/asm-ia64/Kbuild               |    9 
> >  include/asm-parisc/Kbuild             |    2 
> >  include/asm-powerpc/Kbuild            |   59 +--
> >  include/asm-s390/Kbuild               |    7 
> >  include/asm-sh/Kbuild                 |    9 
> >  include/asm-sparc/Kbuild              |    7 
> >  include/asm-sparc64/Kbuild            |    5 
> >  include/asm-x86/Kbuild                |   27 -
> >  include/linux/Kbuild                  |  399 ++++++++++++--------------
> >  include/linux/byteorder/Kbuild        |    6 
> >  include/linux/dvb/Kbuild              |    7 
> >  include/linux/netfilter/Kbuild        |   17 -
> >  include/linux/netfilter_arp/Kbuild    |    3 
> >  include/linux/netfilter_bridge/Kbuild |    5 
> >  include/linux/netfilter_ipv4/Kbuild   |    5 
> >  include/linux/netfilter_ipv6/Kbuild   |    3 
> >  include/linux/nfsd/Kbuild             |   12 
> >  include/linux/sunrpc/Kbuild           |    2 
> >  include/sound/Kbuild                  |    9 
> >  include/video/Kbuild                  |    4 
> >  scripts/Makefile.headersinst          |   27 -
> >  27 files changed, 343 insertions(+), 374 deletions(-)
> 
> This is going to be a bit of a pain for everyone - people are forever
> patching those Kbuild files.
> 
> Is there a way in which we can do this in stages?  Treat header-y in
> the same manner as unifdef-y, then get all the unifdef-y's switched over
> to header-y and once that is done, remove the "treat header-y in the same
> manner as unifdef-y" support?

I had following untested patch in mind.

diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst
index 53dae3e..4cbf9ea 100644
--- a/scripts/Makefile.headersinst
+++ b/scripts/Makefile.headersinst
@@ -50,11 +50,9 @@ ifeq ($(obj)$(ALTARCH),include/asm-$(ARCH)$(BIASMDIR))
      _dst := include/asm
 endif
 
-header-y	:= $(sort $(header-y))
-unifdef-y	:= $(sort $(unifdef-y))
-subdir-y	:= $(patsubst %/,%,$(filter %/, $(header-y)))
-header-y	:= $(filter-out %/, $(header-y))
-header-y	:= $(filter-out $(unifdef-y),$(header-y))
+unifdef-y	:= $(sort $(unifdef-y) $(header-y))
+subdir-y	:= $(patsubst %/,%,$(filter %/, $(unidef-y)))
+header-y        :=
 
 # stamp files for header checks
 check-y		:= $(patsubst %,.check.%,$(header-y) $(unifdef-y) $(objhdr-y))

And then separate patches for each directory under include/ so
they are easy to drop in case of conflicts.

Then I expect we will have it 90% sorted out in first week of the merge and
the remaining 10% should be easy to sort out.

PS. I need to dig out my old patch optimizing Makefile.headerinst so we
eventually can simplify Makefile.headerinst and speed it up.
But lacking time...

	Sam