AC_MSG_ERROR([This appears to be XenServer $ovs_cv_xsversion, but only XenServer 5.6.100 or later is supported. (If you are really using a supported version of XenServer, you may override this error message by specifying 'ovs_cv_xsversion=5.6.100' on the "configure" command line.)])
;;
esac])
+
+dnl OVS_MAKE_HAS_IF([if-true], [if-false])
+dnl
+dnl Checks whether make has the GNU make $(if condition,then,else) extension.
+dnl Runs 'if-true' if so, 'if-false' otherwise.
+AC_DEFUN([OVS_MAKE_HAS_IF],
+ [AC_CACHE_CHECK(
+ [whether ${MAKE-make} has GNU make \$(if) extension],
+ [ovs_cv_gnu_make_if],
+ [cat <<'EOF' > conftest.mk
+conftest.out:
+ echo $(if x,y,z) > conftest.out
+.PHONY: all
+EOF
+ rm -f conftest.out
+ AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
+ ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
+ AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
+ cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
+ result=`cat conftest.out`
+ rm -f conftest.mk conftest.out
+ if test "X$result" = "Xy"; then
+ ovs_cv_gnu_make_if=yes
+ else
+ ovs_cv_gnu_make_if=no
+ fi])
+ AS_IF([test $ovs_cv_gnu_make_if = yes], [$1], [$2])])
+
+dnl OVS_ENABLE_SPARSE
+AC_DEFUN([OVS_ENABLE_SPARSE],
+ [OVS_MAKE_HAS_IF(
+ [AC_CONFIG_COMMANDS_PRE(
+ [: ${SPARSE=sparse}
+ AC_SUBST([SPARSE])
+ CC='$(if $(C),REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse" cgcc,'"$CC"')'])])])
OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
OVS_CONDITIONAL_CC_OPTION([-Wno-unused-parameter], [HAVE_WNO_UNUSED_PARAMETER])
OVS_ENABLE_WERROR
+OVS_ENABLE_SPARSE
AC_ARG_VAR(KARCH, [Kernel Architecture String])
AC_SUBST(KARCH)