[libvirt] [PATCHv2 12/12] build: require Jansson if QEMU driver is enabled

[Ján Tomko]

If the QEMU driver was requested, require Jansson, since we need to use
the JSON monitor to probe capabilities for all QEMU version supported
by libvirt.

Switch the default from 'yes' to 'check', and enable the QEMU driver
by default if the Jansson library is present.

Signed-off-by: Ján Tomko <jtomko at redhat.com>
---
 m4/virt-driver-qemu.m4 | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/m4/virt-driver-qemu.m4 b/m4/virt-driver-qemu.m4
index b9bafdab90..a0d34f1dca 100644
--- a/m4/virt-driver-qemu.m4
+++ b/m4/virt-driver-qemu.m4
@@ -18,7 +18,7 @@ dnl <http://www.gnu.org/licenses/>.
 dnl
 
 AC_DEFUN([LIBVIRT_DRIVER_ARG_QEMU], [
-  LIBVIRT_ARG_WITH_FEATURE([QEMU], [QEMU/KVM], [yes])
+  LIBVIRT_ARG_WITH_FEATURE([QEMU], [QEMU/KVM], [check])
   LIBVIRT_ARG_WITH([QEMU_USER], [username to run QEMU system instance as],
                    ['platform dependent'])
   LIBVIRT_ARG_WITH([QEMU_GROUP], [groupname to run QEMU system instance as],
@@ -26,6 +26,12 @@ AC_DEFUN([LIBVIRT_DRIVER_ARG_QEMU], [
 ])
 
 AC_DEFUN([LIBVIRT_DRIVER_CHECK_QEMU], [
+  if test "$with_qemu:$with_jansson" = "yes:no"; then
+    AC_MSG_ERROR([Jansson >= 2.7 is required to build QEMU driver])
+  fi
+  if test "$with_qemu" = "check"; then
+    with_qemu=$with_jansson
+  fi
   if test "$with_qemu" = "yes" ; then
     AC_DEFINE_UNQUOTED([WITH_QEMU], 1, [whether QEMU driver is enabled])
   fi
-- 
2.16.1