[PATCH] ppc: fix build with O=$(output_dir)

[PATCH] ppc: fix build with O=$(output_dir)

[Roland Dreier]

Recent changes to arch/ppc/boot/lib/Makefile cause

      CC      arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o
    Assembler messages:
    FATAL: can't create arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o: No such file or directory

when building a ppc kernel using O=$(output_dir) with CONFIG_ZLIB_INFLATE=n,
because the $(output_dir)/lib/zlib_inflate directory doesn't get created.

This patch, which makes arch/ppc/boot/lib/Makefile create the
directory if needed, is one fix for the problem.

Signed-off-by: Roland Dreier <roland@topspin.com>

Index: linux-2.6.9/arch/ppc/boot/lib/Makefile
===================================================================
--- linux-2.6.9.orig/arch/ppc/boot/lib/Makefile	2004-10-18 14:54:55.000000000 -0700
+++ linux-2.6.9/arch/ppc/boot/lib/Makefile	2004-10-18 23:41:28.000000000 -0700
@@ -4,7 +4,13 @@
 
 CFLAGS_kbd.o	+= -Idrivers/char
 
-lib-y := $(addprefix ../../../../lib/zlib_inflate/, \
+ZLIB_DIR := ../../../../lib/zlib_inflate/
+
+lib-y := $(addprefix $(ZLIB_DIR), \
            infblock.o infcodes.o inffast.o inflate.o inftrees.o infutil.o)
 lib-y += div64.o
 lib-$(CONFIG_VGA_CONSOLE) += vreset.o kbd.o
+
+ifneq ($(KBUILD_SRC),)
+_make_zlib_dir := $(shell [ -d $(obj)/$(ZLIB_DIR) ] || mkdir -p $(obj)/$(ZLIB_DIR) )
+endif

Re: [PATCH] ppc: fix build with O=$(output_dir)

[Tom Rini]

On Mon, Oct 18, 2004 at 11:48:22PM -0700, Roland Dreier wrote:

> Recent changes to arch/ppc/boot/lib/Makefile cause
> 
>       CC      arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o
>     Assembler messages:
>     FATAL: can't create arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o: No such file or directory
> 
> when building a ppc kernel using O=$(output_dir) with CONFIG_ZLIB_INFLATE=n,
> because the $(output_dir)/lib/zlib_inflate directory doesn't get created.
> 
> This patch, which makes arch/ppc/boot/lib/Makefile create the
> directory if needed, is one fix for the problem.

IMHO, this is the uglier of the two fixes for the problem, as this means
you'll still be clobbering lib/zlib_inflate/*.o when ZLIB_INFLATE!=n.
The other is to go back to putting the object in $(O)/arch/ppc/boot/lib/
and copying the guts of the .c.o rule to arch/ppc/boot/lib/Makefile

Sam, any chance you've had time to think up a good fix to this?  Thanks.

-- 
Tom Rini
http://gate.crashing.org/~trini/

Re: [PATCH] ppc: fix build with O=$(output_dir)

[Tom Rini]

On Thu, Oct 21, 2004 at 05:56:14PM +0000, roland@topspin.com wrote:
> ChangeSet 1.2040, 2004/10/21 10:56:14-07:00, roland@topspin.com
> 
> 	[PATCH] ppc: fix build with O=$(output_dir)
> 	
> 	Recent changes to arch/ppc/boot/lib/Makefile cause
> 	
> 	      CC      arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o
> 	    Assembler messages:
> 	    FATAL: can't create arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o: No such file or directory
> 	
> 	when building a ppc kernel using O=$(output_dir) with CONFIG_ZLIB_INFLATE=n,
> 	because the $(output_dir)/lib/zlib_inflate directory doesn't get created.
> 	
> 	This patch, which makes arch/ppc/boot/lib/Makefile create the
> 	directory if needed, is one fix for the problem.
> 	
> 	Signed-off-by: Roland Dreier <roland@topspin.com>
> 	Signed-off-by: Andrew Morton <akpm@osdl.org>
> 	Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Can we back this out please?  As I noted on lkml once I saw this, it
still doesn't fix the problem of overwriting files in lib/zlib_inflate/
if ZLIB_INFLATE!=n, and adding explicit rules for lib/zlib_inflate/foo.c
-> ./foo.o looks quite bad (it's 2 calls if we want checker to get
invoked, one if we skip doing that).  At the end of the thread, both
Roland and I were hoping Sam knew of a clever solution to this.

-- 
Tom Rini
http://gate.crashing.org/~trini/

Re: [PATCH] ppc: fix build with O=$(output_dir)

[Tom Rini]

On Thu, Oct 21, 2004 at 05:56:14PM +0000, roland@topspin.com wrote:
> ChangeSet 1.2040, 2004/10/21 10:56:14-07:00, roland@topspin.com
> 
> 	[PATCH] ppc: fix build with O=$(output_dir)
> 	
> 	Recent changes to arch/ppc/boot/lib/Makefile cause
> 	
> 	      CC      arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o
> 	    Assembler messages:
> 	    FATAL: can't create arch/ppc/boot/lib/../../../../lib/zlib_inflate/infblock.o: No such file or directory
> 	
> 	when building a ppc kernel using O=$(output_dir) with CONFIG_ZLIB_INFLATE=n,
> 	because the $(output_dir)/lib/zlib_inflate directory doesn't get created.
> 	
> 	This patch, which makes arch/ppc/boot/lib/Makefile create the
> 	directory if needed, is one fix for the problem.
> 	
> 	Signed-off-by: Roland Dreier <roland@topspin.com>
> 	Signed-off-by: Andrew Morton <akpm@osdl.org>
> 	Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Can we back this out please?  As I noted on lkml once I saw this, it
still doesn't fix the problem of overwriting files in lib/zlib_inflate/
if ZLIB_INFLATE!=n, and adding explicit rules for lib/zlib_inflate/foo.c
-> ./foo.o looks quite bad (it's 2 calls if we want checker to get
invoked, one if we skip doing that).  At the end of the thread, both
Roland and I were hoping Sam knew of a clever solution to this.

-- 
Tom Rini
http://gate.crashing.org/~trini/

Re: [PATCH] ppc: fix build with O=$(output_dir)

[Roland Dreier]

    Tom> Can we back this out please?  As I noted on lkml once I saw
    Tom> this, it still doesn't fix the problem of overwriting files
    Tom> in lib/zlib_inflate/ if ZLIB_INFLATE!=n, and adding explicit
    Tom> rules for lib/zlib_inflate/foo.c
    -> ./foo.o looks quite bad (it's 2 calls if we want checker to get
    Tom> invoked, one if we skip doing that).  At the end of the
    Tom> thread, both Roland and I were hoping Sam knew of a clever
    Tom> solution to this.

I can't really object to backing this out, but I'll just point out
that without this patch, in the situations where mainline builds at
all, it still overwrites files in lib/zlib_inflate/.  (And builds with
O=xxx don't work at all)

It might make more sense to leave this patch in for now and beg Sam
for a better fix in the future.

Thanks,
  Roland