Linux: Use kbuild to check for UML

<linux/autoconf.h> is automatically included by kbuild; you aren’t
supposed to include it directly.  That breaks in 2.6.33 because
<linux/autoconf.h> is moving to <generated/autoconf.h>.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Change-Id: I56c90dfe90ef72408620793fcd4e927ea3d8f468
Reviewed-on: http://gerrit.openafs.org/1350
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 660c7a3952f36fc892e12aa6b11eda3295b1416d)
Reviewed-on: http://gerrit.openafs.org/1374

diff --git a/acinclude.m4 b/acinclude.m4
index 84cd5885350907baaf233549d4f92ad7192b8fd2..f132f2268fa067f01f07959bb69ad66891be610e 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -684,10 +684,8 @@ else
                        fi
                        _AFS_SYSNAME=`echo $AFS_SYSNAME|sed s/XX\$/$AFS_SYSKVERS/`
                        AFS_SYSNAME="$_AFS_SYSNAME"
-                       save_CPPFLAGS="$CPPFLAGS"
-                       CPPFLAGS="-I${LINUX_KERNEL_PATH}/include $CPPFLAGS"
-                       AC_TRY_COMPILE(
-                        [#include <linux/autoconf.h>],
+                       AC_TRY_KBUILD(
+                        [],
                         [#ifndef CONFIG_USERMODE
                          #error not UML
                          #endif],
@@ -695,7 +693,6 @@ else
                        if test "${ac_cv_linux_is_uml}" = yes; then
                         _AFS_SYSNAME=`echo $AFS_SYSNAME|sed s/linux/umlinux/`
                        fi
-                       CPPFLAGS="$save_CPPFLAGS"
                        AFS_SYSNAME="$_AFS_SYSNAME"
                        ;;
        esac