Re: [PATCH -mm] replacement for broken kbuild-dont-put-temp-files-in-the-source-tree.patch

[Horst Schirmeier <horst@schirmeier.com>]

On Sat, 28 Oct 2006, Andi Kleen wrote:
> On Saturday 28 October 2006 16:07, Horst Schirmeier wrote:
> > Hello,
> >
> > the kbuild-dont-put-temp-files-in-the-source-tree.patch (-mm patches) is
> > implemented faultily and fails in its intention to put temporary files
> > in $TMPDIR (or /tmp by default).
> >
> > This is the code as it results from the patch:
> >
> > ASTMP = $(shell mktemp ${TMPDIR:-/tmp}/asXXXXXX)
> 
> I'm still against mktemp. It eats random entropy and
> temporary files should be in the objdir, not in /tmp

TBH, I don't see the necessity of temporary files at all in this case,
but I assumed there must be a reason for them as the change already made
it into the -mm tree.

Why not use -o /dev/null, as Daniel Drake already suggested in [1]? In
both as-instr and ld-option, the tmp file is being deleted
unconditionally right after its creation anyways.

The attached patch is adapted from the patches proposed in [2], redone
as a replacement for
kbuild-dont-put-temp-files-in-the-source-tree.patch. Comments?

Kind regards,
 Horst

[1] LKML Message-ID: <452F9602.1050906@gentoo.org>
[2] http://bugs.gentoo.org/show_bug.cgi?id=149307

---
Do not write temporary files in as-instr and ld-option but write to
/dev/null, as the output is not being used anyways.

Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: jpdenheijer@gmail.com
Signed-off-by: Horst Schirmeier <horst@schirmeier.com>
---

 Kbuild.include |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- linux-mm/scripts/Kbuild.include.orig	2006-10-29 00:39:35.000000000 +0200
+++ linux-mm/scripts/Kbuild.include	2006-10-29 12:56:39.000000000 +0100
@@ -66,9 +66,8 @@ as-option = $(shell if $(CC) $(CFLAGS) $
 # as-instr
 # Usage: cflags-y += $(call as-instr, instr, option1, option2)
 
-as-instr = $(shell if echo -e "$(1)" | $(AS) >/dev/null 2>&1 -W -Z -o astest$$$$.out ; \
-		   then echo "$(2)"; else echo "$(3)"; fi; \
-	           rm -f astest$$$$.out)
+as-instr = $(shell if echo -e "$(1)" | $(AS) >/dev/null 2>&1 -W -Z -o /dev/null ; \
+		   then echo "$(2)"; else echo "$(3)"; fi)
 
 # cc-option
 # Usage: cflags-y += $(call cc-option, -march=winchip-c6, -march=i586)
@@ -98,9 +97,8 @@ cc-ifversion = $(shell if [ $(call cc-ve
 # ld-option
 # Usage: ldflags += $(call ld-option, -Wl$(comma)--hash-style=both)
 ld-option = $(shell if $(CC) $(1) \
-			     -nostdlib -o ldtest$$$$.out -xc /dev/null \
-             > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi; \
-	     rm -f ldtest$$$$.out)
+			     -nostdlib -o /dev/null -xc /dev/null \
+             > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi)
 
 ###
 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=