configure.ac: don't depend on automake 1.11

AM_SILENT_RULES is not available in earlier versions of automake,
so test for its presence before calling it.

Reported-by: Louis-Noel Pouchet <pouchet@cse.ohio-state.edu>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/configure.ac b/configure.ac
index 5bfda6d..a7cb540 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@ AC_INIT
 AC_CONFIG_AUX_DIR([.])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE(isl, 0.06)
-AM_SILENT_RULES([yes])
+m4_ifdef([AM_SILENT_RULES],[AM_SILENT_RULES([yes])])
 AC_SUBST(versioninfo)
 versioninfo=6:0:0