X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=config%2Flustre-build-linux.m4;h=e1b46a374080a2c1b37d62246dc74f697c884470;hp=a26759e7efd25b0047fc1c31720704fb6e251c7e;hb=2250e072c37855d611aa64027945981fe2c8f4d7;hpb=1e0ab9df0e0d6e166ed1d4c83c3fa919a05d61b1

diff --git a/config/lustre-build-linux.m4 b/config/lustre-build-linux.m4
index a26759e..e1b46a3 100644
--- a/config/lustre-build-linux.m4
+++ b/config/lustre-build-linux.m4
@@ -3,33 +3,35 @@
 #
 # Set things accordingly for a linux kernel
 #
-AC_DEFUN([LB_LINUX_VERSION],[
+AC_DEFUN([LB_LINUX_VERSION], [
 KMODEXT=".ko"
+AC_SUBST(KMODEXT)
 
-MODULE_TARGET="SUBDIRS"
 makerule="$PWD/build"
-AC_MSG_CHECKING([for external module build support])
+AC_CACHE_CHECK([for external module build target], lb_cv_module_target, [
+lb_cv_module_target=""
+MODULE_TARGET="SUBDIRS"
 rm -f build/conftest.i
-LB_LINUX_TRY_MAKE([],[],
+LB_LINUX_TRY_MAKE([], [],
 	[$makerule LUSTRE_KERNEL_TEST=conftest.i],
 	[test -s build/conftest.i],
-	[
-		AC_MSG_RESULT([no])
-	],[
-		makerule="_module_$makerule"
+	[lb_cv_module_target="SUBDIRS"], [
 		MODULE_TARGET="M"
-		LB_LINUX_TRY_MAKE([],[],
+		makerule="_module_$PWD/build"
+		LB_LINUX_TRY_MAKE([], [],
 			[$makerule LUSTRE_KERNEL_TEST=conftest.i],
 			[test -s build/conftest.i],
-			[
-				AC_MSG_RESULT([yes])
-			],[
+			[lb_cv_module_target="M"], [
 				AC_MSG_ERROR([unknown; check config.log for details])
 			])
 	])
-
+])
+AS_IF([test -z "$lb_cv_module_target"],
+	[AC_MSG_ERROR([unknown external module build target])],
+[test "x$lb_cv_module_target" = "xM"],
+	[makerule="_module_$PWD/build"])
+MODULE_TARGET=$lb_cv_module_target
 AC_SUBST(MODULE_TARGET)
-AC_SUBST(KMODEXT)
 ])
 
 #
@@ -38,146 +40,205 @@ AC_SUBST(KMODEXT)
 # Determine the Linux kernel version string from the utsrelease
 #
 AC_DEFUN([LB_LINUX_UTSRELEASE], [
-	AC_MSG_CHECKING([kernel source version])
-
-	utsrelease1=${LINUX_OBJ}/include/generated/utsrelease.h
-	utsrelease2=${LINUX_OBJ}/include/linux/utsrelease.h
-	utsrelease3=${LINUX_OBJ}/include/linux/version.h
-	AS_IF([test -r ${utsrelease1} && fgrep -q UTS_RELEASE ${utsrelease1}], [
-		utsrelease=${utsrelease1}
-	], [test -r ${utsrelease2} && fgrep -q UTS_RELEASE ${utsrelease2}], [
-		utsrelease=${utsrelease2}
-	], [test -r ${utsrelease3} && fgrep -q UTS_RELEASE ${utsrelease3}], [
-		utsrelease=${utsrelease3}
-	])
-
-	AS_IF([test ! -z "${utsrelease}"], [
-		UTS_RELEASE=$(awk -F \" '/ UTS_RELEASE / { print [$]2 }' \
-		              ${utsrelease})
-		AS_IF([test -z "$UTS_RELEASE"], [
-			AC_MSG_RESULT([Not found])
-			AC_MSG_ERROR([*** Cannot determine kernel version.])
-		])
-	], [
-		AC_MSG_RESULT([Not found])
-		AC_MSG_ERROR([
-	*** Cannot find UTS_RELEASE definition.
-	*** This is often provided by the kernel-devel package.])
+AC_CACHE_CHECK([for Linux kernel utsrelease], lb_cv_utsrelease, [
+lb_cv_utsrelease=""
+utsrelease1=$LINUX_OBJ/include/generated/utsrelease.h
+utsrelease2=$LINUX_OBJ/include/linux/utsrelease.h
+utsrelease3=$LINUX_OBJ/include/linux/version.h
+AS_IF([test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1],
+	[utsrelease=$utsrelease1],
+[test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2],
+	[utsrelease=$utsrelease2],
+[test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3],
+	[utsrelease=$utsrelease3])
+AS_IF([test -n "$utsrelease"],
+	[lb_cv_utsrelease=$(awk -F \" '/ UTS_RELEASE / { print [$]2 }' $utsrelease)],
+	[AC_MSG_ERROR([
+
+Cannot find UTS_RELEASE definition.
+
+This is often provided by the kernel-devel package.
+])
 	])
-
-	AC_MSG_RESULT([${UTS_RELEASE}])
-
-	LINUX_VERSION=${UTS_RELEASE}
-	AC_SUBST(LINUX_VERSION)
-	LINUXRELEASE=${UTS_RELEASE}
-	AC_SUBST(LINUXRELEASE)
 ])
-
+AS_IF([test -z "$lb_cv_utsrelease"],
+	[AC_MSG_ERROR([Cannot determine Linux kernel version.])])
+LINUXRELEASE=$lb_cv_utsrelease
+AC_SUBST(LINUXRELEASE)
+])
 
 #
 # LB_LINUX_RELEASE
 #
 # get the release version of linux
 #
-AC_DEFUN([LB_LINUX_RELEASE],
-[
-LB_LINUX_UTSRELEASE
-
-moduledir='$(CROSS_PATH)/lib/modules/$(LINUXRELEASE)/updates/kernel'
-AC_SUBST(moduledir)
-
-modulefsdir='$(moduledir)/fs/$(PACKAGE)'
-AC_SUBST(modulefsdir)
-
-modulenetdir='$(moduledir)/net/$(PACKAGE)'
-AC_SUBST(modulenetdir)
-
-# ------------ RELEASE --------------------------------
-AC_MSG_CHECKING([for Lustre release])
-AC_ARG_WITH([release],[
-	AC_HELP_STRING([--with-release=string],
-		       [set the release string (default=$kvers_YYYYMMDDhhmm)]),
-	[RELEASE=$withval],
-	RELEASE=""
-	if test -n "$DOWNSTREAM_RELEASE"; then
-		RELEASE="${DOWNSTREAM_RELEASE}_"
-	fi
-	RELEASE="$RELEASE`echo ${LINUXRELEASE} | tr '-' '_'`_$BUILDID"
-])
-AC_MSG_RESULT($RELEASE)
-AC_SUBST(RELEASE)
-
-# check if the kernel is one from RHEL or SUSE
-AC_MSG_CHECKING([for RedHat kernel version])
-	AS_IF([fgrep -q RHEL_RELEASE ${LINUX_OBJ}/include/$VERSION_HDIR/version.h], [
+AC_DEFUN([LB_LINUX_RELEASE], [
+	LB_LINUX_UTSRELEASE
+
+	# Define default states
+	RHEL_KERNEL="no"
+	SUSE_KERNEL="no"
+	UBUNTU_KERNEL="no"
+	DEBIAN_KERNEL="no"
+	# And if any of the above kernels has been detected yet
+	KERNEL_FOUND="no"
+
+	# Check for RedHat first (no need to check KERNEL_FOUND
+	AC_CACHE_CHECK([for RedHat kernel release number], lb_cv_rhel_kernel_version, [
+		lb_cv_rhel_kernel_version=""
+		AS_IF([fgrep -q RHEL_RELEASE $LINUX_OBJ/include/$VERSION_HDIR/version.h], [
+			lb_cv_rhel_kernel_version=$(awk '/ RHEL_MAJOR / { print [$]3 }' \
+				$LINUX_OBJ/include/$VERSION_HDIR/version.h)$(awk \
+				'/ RHEL_MINOR / { print [$]3 }' \
+				$LINUX_OBJ/include/$VERSION_HDIR/version.h)
+		])
+	])
+	AS_IF([test -n "$lb_cv_rhel_kernel_version"], [
 		RHEL_KERNEL="yes"
-		RHEL_RELEASE=$(expr 0$(awk -F \" '/ RHEL_RELEASE / { print [$]2 }' \
-			       ${LINUX_OBJ}/include/$VERSION_HDIR/version.h) + 1)
-		KERNEL_VERSION=$(sed -e 's/\(@<:@23@:>@\.@<:@0-9@:>@*\.@<:@0-9@:>@*\).*/\1/' <<< ${LINUXRELEASE})
-		RHEL_KERNEL_VERSION=${KERNEL_VERSION}-${RHEL_RELEASE}
-		AC_SUBST(RHEL_KERNEL_VERSION)
-		AC_MSG_RESULT([${RHEL_KERNEL_VERSION}])
-	], [
-		AC_MSG_RESULT([not found])
-		LB_LINUX_CONFIG([SUSE_KERNEL],[SUSE_KERNEL="yes"],[])
+		KERNEL_FOUND="yes"
+		RHEL_RELEASE_NO=$lb_cv_rhel_kernel_version
+	])
+
+	# Check for SuSE
+	AS_IF([test "x$KERNEL_FOUND" = "xno"], [
+		LB_CHECK_CONFIG([SUSE_KERNEL], [
+			SUSE_KERNEL="yes"
+			KERNEL_FOUND="yes"
+		], [])
+	])
+
+	# Check for Ubuntu
+	AS_IF([test "x$KERNEL_FOUND" = "xno"], [
+		AC_CACHE_CHECK([for Ubuntu kernel signature], lb_cv_ubuntu_kernel_sig, [
+			lb_cv_ubuntu_kernel_sig="no"
+			AS_IF([fgrep -q "CONFIG_VERSION_SIGNATURE \"Ubuntu" $LINUX_OBJ/include/generated/autoconf.h], [
+				lb_cv_ubuntu_kernel_sig="yes"
+			])
+		])
+		AS_IF([test "x$lb_cv_ubuntu_kernel_sig" = "xyes"], [
+			UBUNTU_KERNEL="yes"
+			KERNEL_FOUND="yes"
+		])
+	])
+
+	# Check for Debian
+	AS_IF([test "x$KERNEL_FOUND" = "xno"], [
+		AC_CACHE_CHECK([for Debian kernel signature], lb_cv_debian_kernel_sig, [
+			lb_cv_debian_kernel_sig="no"
+			AS_IF([grep -q "LINUX_PACKAGE_ID\s*\"\s*Debian" $LINUX_OBJ/include/generated/package.h], [
+				lb_cv_debian_kernel_sig="yes"
+			])
+		])
+		AS_IF([test "x$lb_cv_debian_kernel_sig" = "xyes"], [
+			DEBIAN_KERNEL="yes"
+			KERNEL_FOUND="yes"
+		])
 	])
+
+	# If still no kernel was found, a warning is issued
+	AS_IF([test "x$KERNEL_FOUND" = "xno"], [
+		AC_MSG_WARN([Kernel Distro seems to be neither RedHat, SuSE, Ubuntu nor Debian])
+	])
+
+	AC_MSG_CHECKING([for Linux kernel module package directory])
+	AC_ARG_WITH([kmp-moddir],
+		AC_HELP_STRING([--with-kmp-moddir=string],
+			[set the kmod updates or extra directory]),
+		[KMP_MODDIR=$withval
+		 IN_KERNEL=''],[
+		AS_IF([test x$RHEL_KERNEL = xyes], [KMP_MODDIR="extra/kernel"],
+			  [test x$SUSE_KERNEL = xyes], [KMP_MODDIR="updates/kernel"],
+			  [test x$UBUNTU_KERNEL = xyes], [KMP_MODDIR="updates/kernel"],
+			  [test x$DEBIAN_KERNEL = xyes], [KMP_MODDIR="updates/kernel"],
+			  [AC_MSG_WARN([Kernel Distro seems to be neither RedHat, SuSE, Ubuntu nor Debian])]
+		)
+		IN_KERNEL="${PACKAGE}"])
+	AC_MSG_RESULT($KMP_MODDIR)
+
+	moduledir="/lib/modules/${LINUXRELEASE}/${KMP_MODDIR}"
+
+	modulefsdir="${moduledir}/fs/${IN_KERNEL}"
+	AC_SUBST(modulefsdir)
+
+	modulenetdir="${moduledir}/net/${IN_KERNEL}"
+	AC_SUBST(modulenetdir)
+
+	AC_SUBST(KMP_MODDIR)
+])
+
+#
+# LB_LINUX_SYMVERFILE
+#
+# SLES 9 uses a different name for this file - unsure about vanilla kernels
+# around this version, but it matters for servers only.
+AC_DEFUN([LB_LINUX_SYMVERFILE], [
+AC_CACHE_CHECK([for the name of module symbol version file], lb_cv_module_symvers, [
+AS_IF([grep -q Modules.symvers $LINUX/scripts/Makefile.modpost],
+	[lb_cv_module_symvers=Modules.symvers],
+	[lb_cv_module_symvers=Module.symvers])
+])
+SYMVERFILE=$lb_cv_module_symvers
+AC_SUBST(SYMVERFILE)
 ])
 
+#
 # LB_ARG_REPLACE_PATH(PACKAGE, PATH)
-AC_DEFUN([LB_ARG_REPLACE_PATH],[
-	new_configure_args=
-	eval "set x $ac_configure_args"
-	shift
-	for arg; do
-		case $arg in
-			--with-[$1]=*)
-				arg=--with-[$1]=[$2]
-				;;
-			*\'*)
-				arg=$(printf %s\n ["$arg"] | \
-				      sed "s/'/'\\\\\\\\''/g")
-				;;
-		esac
-		dnl AS_VAR_APPEND([new_configure_args], [" '$arg'"])
-		new_configure_args="$new_configure_args \"$arg\""
-	done
-	ac_configure_args=$new_configure_args
+#
+AC_DEFUN([LB_ARG_REPLACE_PATH], [
+new_configure_args=
+eval set -- $ac_configure_args
+for arg; do
+	case $arg in
+		--with-[$1]=*)
+			arg=--with-[$1]=[$2] ;;
+		*\'*)
+			arg=$(printf %s\n ["$arg"] | sed "s/'/'\\\\\\\\''/g") ;;
+	esac
+	dnl AS_VAR_APPEND([new_configure_args], [" '$arg'"])
+	new_configure_args="$new_configure_args '$arg'"
+done
+ac_configure_args=$new_configure_args
 ])
 
+#
+# __LB_ARG_CANON_PATH
+#
 # this is the work-horse of the next function
+#
 AC_DEFUN([__LB_ARG_CANON_PATH], [
 	[$3]=$(readlink -f $with_$2)
 	LB_ARG_REPLACE_PATH([$1], $[$3])
 ])
 
+#
+# LB_ARG_CANON_PATH
+#
 # a front-end for the above function that transforms - and . in the
 # PACKAGE portion of --with-PACKAGE into _ suitable for variable names
+#
 AC_DEFUN([LB_ARG_CANON_PATH], [
 	__LB_ARG_CANON_PATH([$1], m4_translit([$1], [-.], [__]), [$2])
 ])
 
 #
-#
 # LB_LINUX_PATH
 #
 # Find paths for linux, handling kernel-source rpms
 #
-AC_DEFUN([LB_LINUX_PATH],
-[# prep some default values
-for DEFAULT_LINUX in /lib/modules/$(uname -r)/{source,build} /usr/src/linux; do
-	if readlink -q -e $DEFAULT_LINUX; then
-		break
-	fi
+AC_DEFUN([LB_LINUX_PATH], [
+for DEFAULT_LINUX in /usr/src/linux-source-* /lib/modules/$(uname -r)/{source,build} /usr/src/linux $(find /usr/src/kernels/ -maxdepth 1 -name @<:@0-9@:>@\* | xargs -r ls -d | tail -n 1); do
+	AS_IF([readlink -q -e $DEFAULT_LINUX >/dev/null], [break])
 done
 if test "$DEFAULT_LINUX" = "/lib/modules/$(uname -r)/source"; then
 	PATHS="/lib/modules/$(uname -r)/build"
+else
+	PATHS="/usr/src/linux-headers-$(uname -r)"
 fi
 PATHS+=" $DEFAULT_LINUX"
 for DEFAULT_LINUX_OBJ in $PATHS; do
-	if readlink -q -e $DEFAULT_LINUX_OBJ; then
-		break
-	fi
+	AS_IF([readlink -q -e $DEFAULT_LINUX_OBJ >/dev/null], [break])
 done
+
 AC_MSG_CHECKING([for Linux sources])
 AC_ARG_WITH([linux],
 	AC_HELP_STRING([--with-linux=path],
@@ -189,17 +250,16 @@ AC_MSG_RESULT([$LINUX])
 AC_SUBST(LINUX)
 
 # -------- check for linux --------
-LB_CHECK_FILE([$LINUX],[],
+LB_CHECK_FILE([$LINUX], [],
 	[AC_MSG_ERROR([Kernel source $LINUX could not be found.])])
 
 # -------- linux objects (for 2.6) --
-AC_MSG_CHECKING([for Linux objects dir])
+AC_MSG_CHECKING([for Linux objects])
 AC_ARG_WITH([linux-obj],
 	AC_HELP_STRING([--with-linux-obj=path],
-			[set path to Linux objects dir (default=/lib/modules/$(uname -r)/build,/usr/src/linux)]),
+			[set path to Linux objects (default=/lib/modules/$(uname -r)/build,/usr/src/linux)]),
 	[LB_ARG_CANON_PATH([linux-obj], [LINUX_OBJ])],
 	[LINUX_OBJ=$DEFAULT_LINUX_OBJ])
-
 AC_MSG_RESULT([$LINUX_OBJ])
 AC_SUBST(LINUX_OBJ)
 
@@ -209,6 +269,14 @@ AC_ARG_WITH([linux-config],
 			[set path to Linux .conf (default=$LINUX_OBJ/.config)])],
 	[LB_ARG_CANON_PATH([linux-config], [LINUX_CONFIG])],
 	[LINUX_CONFIG=$LINUX_OBJ/.config])
+
+# -------- check if .config exists --
+LB_CHECK_FILE([$LINUX_CONFIG], [],
+	[AC_MSG_ERROR([
+
+Kernel config could not be found.
+])
+])
 AC_SUBST(LINUX_CONFIG)
 
 LB_CHECK_FILE([/boot/kernel.h],
@@ -218,138 +286,237 @@ LB_CHECK_FILE([/boot/kernel.h],
 
 AC_ARG_WITH([kernel-source-header],
 	AC_HELP_STRING([--with-kernel-source-header=path],
-			[Use a different kernel version header.  Consult build/README.kernel-source for details.]),
+			[Use a different kernel version header.]),
 	[LB_ARG_CANON_PATH([kernel-source-header], [KERNEL_SOURCE_HEADER])])
 
-# ------------ .config exists ----------------
-LB_CHECK_FILE([$LINUX_CONFIG],[],
-	[AC_MSG_ERROR([Kernel config could not be found.  If you are building from a kernel-source rpm consult build/README.kernel-source])])
-
 # ----------- make dep run? ------------------
 # at 2.6.19 # $LINUX/include/linux/config.h is removed
-# and at more old has only one line
-# include <autoconf.h>
-LB_CHECK_FILE([$LINUX_OBJ/include/generated/autoconf.h],[AUTOCONF_HDIR=generated],
-        [LB_CHECK_FILE([$LINUX_OBJ/include/linux/autoconf.h],[AUTOCONF_HDIR=linux],
-	[AC_MSG_ERROR([Run make config in $LINUX.])])])
-        AC_SUBST(AUTOCONF_HDIR)
-LB_CHECK_FILE([$LINUX_OBJ/include/linux/version.h], [VERSION_HDIR=linux],
+# and at more old has only one line include <autoconf.h>
+#
+LB_CHECK_FILE([$LINUX_OBJ/include/generated/autoconf.h],
+	[AUTOCONF_HDIR=generated],
+	[LB_CHECK_FILE([$LINUX_OBJ/include/linux/autoconf.h],
+		[AUTOCONF_HDIR=linux],
+		[AC_MSG_ERROR([Run make config in $LINUX.])])])
+AC_SUBST(AUTOCONF_HDIR)
+
+LB_CHECK_FILE([$LINUX_OBJ/include/linux/version.h],
+	[VERSION_HDIR=linux],
 	[LB_CHECK_FILE([$LINUX_OBJ/include/generated/uapi/linux/version.h],
 		[VERSION_HDIR=generated/uapi/linux],
-		[AC_MSG_ERROR([Run make config in $LINUX.])])
-	])
-	AC_SUBST(VERSION_HDIR)
+		[AC_MSG_ERROR([Run make config in $LINUX.])])])
+AC_SUBST(VERSION_HDIR)
 
 # ----------- kconfig.h exists ---------------
 # kernel 3.1, $LINUX/include/linux/kconfig.h is added
 # see kernel commit 2a11c8ea20bf850b3a2c60db8c2e7497d28aba99
-LB_CHECK_FILE([$LINUX_OBJ/include/linux/kconfig.h],
-              [CONFIG_INCLUDE=include/linux/kconfig.h],
+#
+LB_CHECK_FILE([$LINUX/include/linux/kconfig.h],
+	      [CONFIG_INCLUDE=$LINUX/include/linux/kconfig.h],
               [CONFIG_INCLUDE=include/$AUTOCONF_HDIR/autoconf.h])
-	AC_SUBST(CONFIG_INCLUDE)
+AC_SUBST(CONFIG_INCLUDE)
 
 # ------------ rhconfig.h includes runtime-generated bits --
-# red hat kernel-source checks
+# RedHat kernel-source checks
 
 # we know this exists after the check above.  if the user
 # tarred up the tree and ran make dep etc. in it, then
 # version.h gets overwritten with a standard linux one.
 
-if grep rhconfig $LINUX_OBJ/include/$VERSION_HDIR/version.h >/dev/null ; then
+AS_IF([grep rhconfig $LINUX_OBJ/include/$VERSION_HDIR/version.h >/dev/null], [
 	# This is a clean kernel-source tree, we need to
-	# enable extensive workarounds to get this to build
-	# modules
-	LB_CHECK_FILE([$KERNEL_SOURCE_HEADER],
-		[if test $KERNEL_SOURCE_HEADER = '/boot/kernel.h' ; then
-			AC_MSG_WARN([Using /boot/kernel.h from RUNNING kernel.])
-			AC_MSG_WARN([If this is not what you want, use --with-kernel-source-header.])
-			AC_MSG_WARN([Consult build/README.kernel-source for details.])
-		fi],
-		[AC_MSG_ERROR([$KERNEL_SOURCE_HEADER not found.  Consult build/README.kernel-source for details.])])
+	# enable extensive workarounds to get this to build modules
+	LB_CHECK_FILE([$KERNEL_SOURCE_HEADER], [
+		AS_IF([test $KERNEL_SOURCE_HEADER = '/boot/kernel.h'],
+			[AC_MSG_WARN([
+
+Using /boot/kernel.h from RUNNING kernel.
+
+If this is not what you want, use --with-kernel-source-header.
+Consult build/README.kernel-source for details.
+])
+		])],
+		[AC_MSG_ERROR([
+
+$KERNEL_SOURCE_HEADER not found.
+
+Consult build/README.kernel-source for details.
+])
+		])
 	EXTRA_KCFLAGS="-include $KERNEL_SOURCE_HEADER $EXTRA_KCFLAGS"
-fi
+])
 
 # this is needed before we can build modules
-LB_LINUX_CROSS
 LB_LINUX_VERSION
 
 # --- check that we can build modules at all
-AC_MSG_CHECKING([that modules can be built at all])
-LB_LINUX_TRY_COMPILE([],[],[
-	AC_MSG_RESULT([yes])
-],[
-	AC_MSG_RESULT([no])
-	AC_MSG_WARN([Consult config.log for details.])
-	AC_MSG_WARN([If you are trying to build with a kernel-source rpm, consult build/README.kernel-source])
-	AC_MSG_ERROR([Kernel modules cannot be built.])
+LB_CHECK_COMPILE([that modules can be built at all], build_modules,
+	[], [], [], [
+	AC_MSG_ERROR([
+
+Kernel modules cannot be built. Consult config.log for details.
+
+If you are trying to build with a kernel-source rpm,
+consult build/README.kernel-source
+])
 ])
 
 LB_LINUX_RELEASE
 ]) # end of LB_LINUX_PATH
 
-# LB_LINUX_SYMVERFILE
-# SLES 9 uses a different name for this file - unsure about vanilla kernels
-# around this version, but it matters for servers only.
-AC_DEFUN([LB_LINUX_SYMVERFILE],
-	[AC_MSG_CHECKING([name of module symbol version file])
-	if grep -q Modules.symvers $LINUX/scripts/Makefile.modpost ; then
-		SYMVERFILE=Modules.symvers
-	else
-		SYMVERFILE=Module.symvers
-	fi
-	AC_MSG_RESULT($SYMVERFILE)
-	AC_SUBST(SYMVERFILE)
-])
-
-#
-# LB_LINUX_CROSS
-#
-# check for cross compilation
-#
-AC_DEFUN([LB_LINUX_CROSS],
-	[AC_MSG_CHECKING([for cross compilation])
-AS_IF([test "x$cross_compiling" = xno], [AC_MSG_RESULT([no])],
-	[case $host_vendor in
-		# The K1OM architecture is an extension of the x86 architecture
-		# and in MPSS 2.1 it's defined in $host_vendor. But in MPSS 3.x
-		# it's defined in $host_arch. So, try to support both case.
-		k1om | mpss)
-			AC_MSG_RESULT([Intel(R) Xeon Phi(TM)])
-			CC_TARGET_ARCH=`$CC -v 2>&1 | grep Target: | sed -e 's/Target: //'`
-			AC_SUBST(CC_TARGET_ARCH)
-			if test \( $CC_TARGET_ARCH != x86_64-k1om-linux \
-				-a $CC_TARGET_ARCH != k1om-mpss-linux \)
-			then
-				AC_MSG_ERROR([Cross compiler not found in PATH.])
-			fi
-			CROSS_VARS="ARCH=k1om CROSS_COMPILE=${CC_TARGET_ARCH}-"
-			CROSS_PATH="${CROSS_PATH:=/opt/lustre/${VERSION}/${CC_TARGET_ARCH}}"
-			CCAS=$CC
-			# need to produce special section for debuginfo extraction
-			LDFLAGS="${LDFLAGS} -Wl,--build-id"
-			EXTRA_KLDFLAGS="${EXTRA_KLDFLAGS} -Wl,--build-id"
-			if test x$enable_server != xno ; then
-				AC_MSG_WARN([Disabling server (not supported for k1om architecture).])
-				enable_server='no'
-			fi
-			;;
-		*)
-			AC_MSG_RESULT([yes, but no changes])
-			;;
-	esac
+#
+# LC_MODULE_LOADING
+#
+# after 2.6.28 CONFIG_KMOD is removed, and only CONFIG_MODULES remains
+# so we test if request_module is implemented or not
+AC_DEFUN([LC_MODULE_LOADING], [
+AC_CACHE_CHECK([if Linux kernel module loading is possible], lb_cv_module_loading, [
+LB_LINUX_TRY_MAKE([
+	#include <linux/kmod.h>
+], [
+	int myretval=ENOSYS ;
+	return myretval;
+], [
+	$makerule LUSTRE_KERNEL_TEST=conftest.i
+], [dnl
+	grep request_module build/conftest.i |dnl
+		grep -v `grep "int myretval=" build/conftest.i |dnl
+			cut -d= -f2 | cut -d" "  -f1`dnl
+		>/dev/null dnl
+], [lb_cv_module_loading="yes"], [lb_cv_module_loading="no"])
+])
+AS_IF([test "$lb_cv_module_loading" = yes],
+	[AC_DEFINE(HAVE_MODULE_LOADING_SUPPORT, 1,
+		[kernel module loading is possible])],
+	[AC_MSG_WARN([
+
+Kernel module loading support is highly recommended.
+
+])
+	])
+])
+
+#
+# LB_PROG_LINUX
+#
+# linux tests
+#
+AC_DEFUN([LB_PROG_LINUX], [
+LB_LINUX_PATH
+LB_LINUX_SYMVERFILE
+
+LB_CHECK_CONFIG([MODULES], [], [
+	AC_MSG_ERROR([
+
+module support is required to build Lustre kernel modules.
+])
+	])
+
+LB_CHECK_CONFIG([MODVERSIONS])
+
+LB_CHECK_CONFIG([KALLSYMS], [], [
+	AC_MSG_ERROR([
+
+Lustre requires that CONFIG_KALLSYMS is enabled in your kernel.
+])
 	])
-AC_SUBST(CROSS_VARS)
-AC_SUBST(CROSS_PATH)
+
+# 2.6.28
+LC_MODULE_LOADING
 ])
 
+#
+# LB_USES_DPKG
+#
+# Determine if the target is a dpkg system or rpm
+#
+AC_DEFUN([LB_USES_DPKG], [
+AC_CACHE_CHECK([if this distro uses dpkg], lb_cv_uses_dpkg, [
+lb_cv_uses_dpkg="no"
+AS_CASE([$(which dpkg 2>/dev/null)],[*/dpkg], [lb_cv_uses_dpkg="yes"])
+])
+uses_dpkg=$lb_cv_uses_dpkg
+])
+
+#
+# LB_CHECK_EXPORT
+#
+# check symbol exported or not
+# $1 - symbol
+# $2 - file(s) for find.
+# $3 - do 'yes'
+# $4 - do 'no'
+#
+# 2.6 based kernels - put modversion info into $LINUX/Module.modvers or check
+#
+AC_DEFUN([LB_CHECK_EXPORT], [
+AS_VAR_PUSHDEF([lb_export], [lb_cv_export_$1])dnl
+AC_CACHE_CHECK([if Linux kernel exports '$1'], lb_export, [
+AS_VAR_SET([lb_export], [no])
+AS_IF([grep -q -E '[[[:space:]]]$1[[[:space:]]]' $LINUX_OBJ/$SYMVERFILE 2>/dev/null],
+	[AS_VAR_SET([lb_export], [yes])],
+	[for file in $2; do
+		AS_IF([grep -q -E "EXPORT_SYMBOL.*\($1\)" "$LINUX/$file" 2>/dev/null], [
+			AS_VAR_SET([lb_export], [yes])
+			break
+		])
+	done])
+])
+AS_VAR_IF([lb_export], [yes], [$3], [$4])[]dnl
+AS_VAR_POPDEF([lb_export])dnl
+]) # LB_CHECK_EXPORT
+
+#
+# LB_CHECK_CONFIG
+#
+# check if a given config option is defined
+# $1 - CONFIG_<name>
+# $2 - do 'yes'
+# $3 - do 'no'
+#
+AC_DEFUN([LB_CHECK_CONFIG], [
+LB_CHECK_COMPILE([if Linux kernel was built with CONFIG_$1],
+config_$1, [
+	#include <$AUTOCONF_HDIR/autoconf.h>
+], [
+	#ifndef CONFIG_$1
+	#error CONFIG_$1 not #defined
+	#endif
+], [$2], [$3])
+]) # LB_CHECK_CONFIG
+
+#
+# LB_CHECK_CONFIG_IM
+#
+# check if a given config option is builtin or as module
+# $1 - CONFIG_<name> or CONFIG_<name>_MODULE
+# $2 - do 'yes'
+# $3 - do 'no'
+#
+AC_DEFUN([LB_CHECK_CONFIG_IM], [
+LB_CHECK_COMPILE([if Linux kernel was built with CONFIG_$1 in or as module],
+config_im_$1, [
+	#include <$AUTOCONF_HDIR/autoconf.h>
+], [
+	#if !(defined(CONFIG_$1) || defined(CONFIG_$1_MODULE))
+	#error CONFIG_$1 and CONFIG_$1_MODULE not #defined
+	#endif
+], [$2], [$3])
+]) # LB_CHECK_CONFIG_IM
+
+#
 # these are like AC_TRY_COMPILE, but try to build modules against the
 # kernel, inside the build directory
+#
 
+#
 # LB_LANG_PROGRAM(C)([PROLOGUE], [BODY])
 # --------------------------------------
+#
 m4_define([LB_LANG_PROGRAM],
 [
 #include <linux/kernel.h>
+#include <linux/module.h>
 $1
 int
 main (void)
@@ -359,18 +526,25 @@ dnl Don't move the `;' right after for the same reason.
 $2
   ;
   return 0;
-}])
+};
+MODULE_LICENSE("GPL");])
 
 #
 # LB_LINUX_COMPILE_IFELSE
 #
 # like AC_COMPILE_IFELSE
 #
+# $1 - AC_LANG_SOURCE()
+# $2 - make target
+# $3 - check command
+# $4 - do 'yes'
+# $5 - do 'no'
+#
 AC_DEFUN([LB_LINUX_COMPILE_IFELSE],
-[m4_ifvaln([$1], [AC_LANG_CONFTEST([$1])])dnl
+[m4_ifvaln([$1], [AC_LANG_CONFTEST([AC_LANG_SOURCE([$1])])])dnl
 rm -f build/conftest.o build/conftest.mod.c build/conftest.ko
-SUBARCH=$(echo $target_cpu | sed -e 's/powerpc64/powerpc/' -e 's/x86_64/x86/' -e 's/i.86/x86/' -e 's/k1om/x86/')
-AS_IF([AC_TRY_COMMAND(cp conftest.c build && make -d [$2] ${LD:+"LD=$LD"} CC="$CC" -f $PWD/build/Makefile LUSTRE_LINUX_CONFIG=$LINUX_CONFIG LINUXINCLUDE="$EXTRA_LNET_INCLUDE -I$LINUX/arch/$SUBARCH/include -I$LINUX/arch/$SUBARCH/include/generated -Iinclude -I$LINUX/include -Iinclude2 -I$LINUX/include/uapi -I$LINUX/include/generated -I$LINUX/arch/$SUBARCH/include/uapi -Iarch/$SUBARCH/include/generated/uapi -I$LINUX/include/uapi -Iinclude/generated/uapi -include $CONFIG_INCLUDE" -o tmp_include_depends -o scripts -o include/config/MARKER -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $CROSS_VARS $MODULE_TARGET=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
+SUBARCH=$(echo $target_cpu | sed -e 's/powerpc.*/powerpc/' -e 's/ppc.*/powerpc/' -e 's/x86_64/x86/' -e 's/i.86/x86/' -e 's/k1om/x86/' -e 's/aarch64.*/arm64/' -e 's/armv7.*/arm/')
+AS_IF([AC_TRY_COMMAND(cp conftest.c build && make -d [$2] LDFLAGS= ${LD:+LD="$LD"} CC="$CC" -f $PWD/build/Makefile LUSTRE_LINUX_CONFIG=$LINUX_CONFIG LINUXINCLUDE="$EXTRA_CHECK_INCLUDE -I$LINUX/arch/$SUBARCH/include -Iinclude -Iarch/$SUBARCH/include/generated -I$LINUX/include -Iinclude2 -I$LINUX/include/uapi -Iinclude/generated -I$LINUX/arch/$SUBARCH/include/uapi -Iarch/$SUBARCH/include/generated/uapi -I$LINUX/include/uapi -Iinclude/generated/uapi ${SPL_OBJ:+-include $SPL_OBJ/spl_config.h} ${ZFS_OBJ:+-include $ZFS_OBJ/zfs_config.h} ${SPL:+-I$SPL -I$SPL/include } ${ZFS:+-I$ZFS -I$ZFS/include} -include $CONFIG_INCLUDE" -o tmp_include_depends -o scripts -o include/config/MARKER -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $MODULE_TARGET=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
 	[$4],
 	[_AC_MSG_LOG_CONFTEST
 m4_ifvaln([$5],[$5])dnl])
@@ -378,74 +552,15 @@ rm -f build/conftest.o build/conftest.mod.c build/conftest.mod.o build/conftest.
 ])
 
 #
-# LB_LINUX_ARCH
-#
-# Determine the kernel's idea of the current architecture
-#
-AC_DEFUN([LB_LINUX_ARCH],
-         [AC_MSG_CHECKING([Linux kernel architecture])
-          AS_IF([rm -f $PWD/build/arch
-                 make -s --no-print-directory echoarch -f $PWD/build/Makefile \
-                     LUSTRE_LINUX_CONFIG=$LINUX_CONFIG -C $LINUX $CROSS_VARS  \
-                     ARCHFILE=$PWD/build/arch && LINUX_ARCH=`cat $PWD/build/arch`],
-                [AC_MSG_RESULT([$LINUX_ARCH])],
-                [AC_MSG_ERROR([Could not determine the kernel architecture.])])
-          rm -f build/arch])
-
-#
 # LB_LINUX_TRY_COMPILE
 #
 # like AC_TRY_COMPILE
 #
-AC_DEFUN([LB_LINUX_TRY_COMPILE],
-[LB_LINUX_COMPILE_IFELSE(
+AC_DEFUN([LB_LINUX_TRY_COMPILE], [
+LB_LINUX_COMPILE_IFELSE(
 	[AC_LANG_SOURCE([LB_LANG_PROGRAM([[$1]], [[$2]])])],
-	[modules],
-	[test -s build/conftest.o],
-	[$3], [$4])])
-
-#
-# LB_LINUX_CONFIG
-#
-# check if a given config option is defined
-#
-AC_DEFUN([LB_LINUX_CONFIG],[
-	AC_MSG_CHECKING([if Linux was built with CONFIG_$1])
-	LB_LINUX_TRY_COMPILE([
-		#include <$AUTOCONF_HDIR/autoconf.h>
-	],[
-		#ifndef CONFIG_$1
-		#error CONFIG_$1 not #defined
-		#endif
-	],[
-		AC_MSG_RESULT([yes])
-		$2
-	],[
-		AC_MSG_RESULT([no])
-		$3
-	])
-])
-
-#
-# LB_LINUX_CONFIG_IM
-#
-# check if a given config option is builtin or as module
-#
-AC_DEFUN([LB_LINUX_CONFIG_IM],[
-	AC_MSG_CHECKING([if Linux was built with CONFIG_$1 in or as module])
-	LB_LINUX_TRY_COMPILE([
-		#include <$AUTOCONF_HDIR/autoconf.h>
-	],[
-		#if !(defined(CONFIG_$1) || defined(CONFIG_$1_MODULE))
-		#error CONFIG_$1 and CONFIG_$1_MODULE not #defined
-		#endif
-	],[
-		AC_MSG_RESULT([yes])
-		$2
-	],[
-		AC_MSG_RESULT([no])
-		$3
-	])
+	[modules], [test -s build/conftest.o],
+	[$3], [$4])
 ])
 
 #
@@ -453,235 +568,45 @@ AC_DEFUN([LB_LINUX_CONFIG_IM],[
 #
 # like LB_LINUX_TRY_COMPILE, but with different arguments
 #
-AC_DEFUN([LB_LINUX_TRY_MAKE],
-	[LB_LINUX_COMPILE_IFELSE(
-		[AC_LANG_SOURCE([LB_LANG_PROGRAM([[$1]], [[$2]])])],
-		[$3], [$4], [$5], [$6]
-	)]
-)
-
-#
-# LB_CONFIG_COMPAT_RDMA
-#
-AC_DEFUN([LB_CONFIG_COMPAT_RDMA],
-[AC_MSG_CHECKING([whether to use Compat RDMA])
-# set default
-AC_ARG_WITH([o2ib],
-	AC_HELP_STRING([--with-o2ib=path],
-		       [build o2iblnd against path]),
-	[
-		case $with_o2ib in
-		yes)    O2IBPATHS="$LINUX $LINUX/drivers/infiniband"
-			ENABLEO2IB=2
-			;;
-		no)     ENABLEO2IB=0
-			;;
-		*)      O2IBPATHS=$with_o2ib
-			ENABLEO2IB=3
-			;;
-		esac
-	],[
-		O2IBPATHS="$LINUX $LINUX/drivers/infiniband"
-		ENABLEO2IB=1
-	])
-if test $ENABLEO2IB -eq 0; then
-	AC_MSG_RESULT([no])
-else
-	o2ib_found=false
-	for O2IBPATH in $O2IBPATHS; do
-		if test \( -f ${O2IBPATH}/include/rdma/rdma_cm.h -a \
-			   -f ${O2IBPATH}/include/rdma/ib_cm.h -a \
-			   -f ${O2IBPATH}/include/rdma/ib_verbs.h -a \
-			   -f ${O2IBPATH}/include/rdma/ib_fmr_pool.h \); then
-			o2ib_found=true
-			break
-		fi
-	done
-	compatrdma_found=false
-	if $o2ib_found; then
-		if test \( -f ${O2IBPATH}/include/linux/compat-2.6.h \); then
-			compatrdma_found=true
-			AC_MSG_RESULT([yes])
-			AC_DEFINE(HAVE_COMPAT_RDMA, 1, [compat rdma found])
-		else
-			AC_MSG_RESULT([no])
-		fi
-	fi
-fi
-])
-
-#
-# LB_CONFIG_OFED_BACKPORTS
-#
-# include any OFED backport headers in all compile commands
-# NOTE: this does only include the backport paths, not the OFED headers
-#       adding the OFED headers is done in the lnet portion
-AC_DEFUN([LB_CONFIG_OFED_BACKPORTS],
-[AC_MSG_CHECKING([whether to use any OFED backport headers])
-if test $ENABLEO2IB -eq 0; then
-	AC_MSG_RESULT([no])
-else
-	if ! $o2ib_found; then
-		AC_MSG_RESULT([no])
-		case $ENABLEO2IB in
-			1) ;;
-			2) AC_MSG_ERROR([kernel OpenIB gen2 headers not present]);;
-			3) AC_MSG_ERROR([bad --with-o2ib path]);;
-			*) AC_MSG_ERROR([internal error]);;
-		esac
-	else
-		if ! $compatrdma_found; then
-			if test -f $O2IBPATH/config.mk; then
-				. $O2IBPATH/config.mk
-			elif test -f $O2IBPATH/ofed_patch.mk; then
-				. $O2IBPATH/ofed_patch.mk
-			fi
-		else
-			case $RHEL_KERNEL_VERSION in
-				2.6.32-358*)
-					EXTRA_LNET_INCLUDE="$EXTRA_LNET_INCLUDE -DCONFIG_COMPAT_RHEL_6_4";;
-			esac
-		fi
-		if test -n "$BACKPORT_INCLUDES"; then
-			OFED_BACKPORT_PATH="$O2IBPATH/${BACKPORT_INCLUDES/*\/kernel_addons/kernel_addons}/"
-			EXTRA_LNET_INCLUDE="-I$OFED_BACKPORT_PATH $EXTRA_LNET_INCLUDE"
-			AC_MSG_RESULT([yes])
-		else
-			AC_MSG_RESULT([no])
-		fi
-	fi
-fi
-])
-
-# LC_MODULE_LOADING
-# after 2.6.28 CONFIG_KMOD is removed, and only CONFIG_MODULES remains
-# so we test if request_module is implemented or not
-AC_DEFUN([LC_MODULE_LOADING],
-[AC_MSG_CHECKING([if kernel module loading is possible])
-LB_LINUX_TRY_MAKE([
-	#include <linux/kmod.h>
-],[
-	int myretval=ENOSYS ;
-	return myretval;
-],[
-	$makerule LUSTRE_KERNEL_TEST=conftest.i
-],[dnl
-	grep request_module build/conftest.i |dnl
-		grep -v `grep "int myretval=" build/conftest.i |dnl
-			cut -d= -f2 | cut -d" "  -f1`dnl
-		>/dev/null dnl
-],[
-	AC_MSG_RESULT(yes)
-	AC_DEFINE(HAVE_MODULE_LOADING_SUPPORT, 1,
-		  [kernel module loading is possible])
-],[
-	AC_MSG_RESULT(no)
-	AC_MSG_WARN([])
-	AC_MSG_WARN([Kernel module loading support is highly recommended.])
-	AC_MSG_WARN([])
-])
+AC_DEFUN([LB_LINUX_TRY_MAKE], [
+LB_LINUX_COMPILE_IFELSE(
+	[AC_LANG_SOURCE([LB_LANG_PROGRAM([[$1]], [[$2]])])],
+	[$3], [$4], [$5], [$6])
 ])
 
 #
-# LB_PROG_LINUX
-#
-# linux tests
-#
-AC_DEFUN([LB_PROG_LINUX],
-[LB_LINUX_PATH
-LB_LINUX_ARCH
-LB_LINUX_SYMVERFILE
-
-
-LB_LINUX_CONFIG([MODULES],[],[
-	AC_MSG_ERROR([module support is required to build Lustre kernel modules.])
-])
-
-LB_LINUX_CONFIG([MODVERSIONS])
-
-LB_LINUX_CONFIG([KALLSYMS],[],[
-	AC_MSG_ERROR([Lustre requires that CONFIG_KALLSYMS is enabled in your kernel.])
-])
-
-# 2.6.28
-LC_MODULE_LOADING
-
-LB_CONFIG_COMPAT_RDMA
-
-# it's ugly to be doing anything with OFED outside of the lnet module, but
-# this has to be done here so that the backports path is set before all of
-# the LN_PROG_LINUX checks are done
-LB_CONFIG_OFED_BACKPORTS
+# LB_CHECK_COMPILE
+# $1 - checking message
+# $2 - variable name
+# $3 - header
+# $4 - body
+# $5 - do 'yes'
+# $6 - do 'no'
+#
+AC_DEFUN([LB_CHECK_COMPILE], [
+AS_VAR_PUSHDEF([lb_compile], [lb_cv_compile_$2])dnl
+AC_CACHE_CHECK([$1], lb_compile, [
+	LB_LINUX_TRY_COMPILE([$3], [$4],
+		[AS_VAR_SET([lb_compile], [yes])],
+		[AS_VAR_SET([lb_compile], [no])])
 ])
+AS_VAR_IF([lb_compile], [yes], [$5], [$6])[]dnl
+AS_VAR_POPDEF([lb_compile])dnl
+]) # LB_CHECK_COMPILE
 
 #
-# LB_CHECK_SYMBOL_EXPORT
-# check symbol exported or not
-# $1 - symbol
-# $2 - file(s) for find.
-# $3 - do 'yes'
-# $4 - do 'no'
-#
-# 2.6 based kernels - put modversion info into $LINUX/Module.modvers
-# or check
-AC_DEFUN([LB_CHECK_SYMBOL_EXPORT],
-[AC_MSG_CHECKING([if Linux was built with symbol $1 exported])
-grep -q -E '[[[:space:]]]$1[[[:space:]]]' $LINUX/$SYMVERFILE 2>/dev/null
-rc=$?
-if test $rc -ne 0; then
-	export=0
-	for file in $2; do
-		grep -q -E "EXPORT_SYMBOL.*\($1\)" "$LINUX/$file" 2>/dev/null
-		rc=$?
-		if test $rc -eq 0; then
-			export=1
-			break;
-		fi
-	done
-	if test $export -eq 0; then
-		AC_MSG_RESULT([no])
-		$4
-	else
-		AC_MSG_RESULT([yes])
-		$3
-	fi
-else
-	AC_MSG_RESULT([yes])
-	$3
-fi
-])
-
+# LB_CHECK_LINUX_HEADER
 #
 # Like AC_CHECK_HEADER but checks for a kernel-space header
 #
-m4_define([LB_CHECK_LINUX_HEADER],
-[AS_VAR_PUSHDEF([ac_Header], [ac_cv_header_$1])dnl
-AC_CACHE_CHECK([for $1], ac_Header,
-	       [LB_LINUX_COMPILE_IFELSE([LB_LANG_PROGRAM([@%:@include <$1>])],
-				  [modules],
-				  [test -s build/conftest.o],
-				  [AS_VAR_SET(ac_Header, [yes])],
-				  [AS_VAR_SET(ac_Header, [no])])])
-AS_IF([test AS_VAR_GET(ac_Header) = yes], [$2], [$3])[]dnl
-AS_VAR_POPDEF([ac_Header])dnl
-])
-
-#
-# LB_USES_DPKG
-#
-# Determine if the target is a dpkg system or rpm
-#
-AC_DEFUN([LB_USES_DPKG],
-[
-AC_MSG_CHECKING([if this distro uses dpkg])
-case `lsb_release -i -s 2>/dev/null` in
-        Ubuntu | Debian)
-                AC_MSG_RESULT([yes])
-                uses_dpkg=yes
-                ;;
-        *)
-                AC_MSG_RESULT([no])
-                uses_dpkg=no
-                ;;
-esac
+m4_define([LB_CHECK_LINUX_HEADER], [
+AS_VAR_PUSHDEF([lb_header], [lb_cv_header_$1])dnl
+AC_CACHE_CHECK([for $1], lb_header, [
+	LB_LINUX_COMPILE_IFELSE([LB_LANG_PROGRAM([@%:@include <$1>])],
+		[modules], [test -s build/conftest.o],
+		[AS_VAR_SET([lb_header], [yes])],
+		[AS_VAR_SET([lb_header], [no])])
 ])
+AS_VAR_IF([lb_header], [yes], [$2], [$3])[]dnl
+AS_VAR_POPDEF([lb_header])dnl
+]) # LB_CHECK_LINUX_HEADER