Restore compatibility with BSD make

m4/ax_valgrind_check.m4

@@ -82,8 +82,8 @@ AC_DEFUN([AX_VALGRIND_DFLT],[
 AC_DEFUN([AX_VALGRIND_CHECK],[
 	dnl Check for --enable-valgrind
 	AC_ARG_ENABLE([valgrind],
-	              [AS_HELP_STRING([--enable-valgrind], [Whether to enable Valgrind on the unit tests (requires GNU make)])],
-	              [enable_valgrind=$enableval],[enable_valgrind=])
+				  [AS_HELP_STRING([--enable-valgrind], [Whether to enable Valgrind on the unit tests (requires GNU make)])],
+				  [enable_valgrind=$enableval],[enable_valgrind=no])
 
 	AS_IF([test "$enable_valgrind" != "no"],[
 		# Check for Valgrind.
@@ -230,6 +230,12 @@ MOSTLYCLEANFILES += $(valgrind_log_files)
 .PHONY: check-valgrind $(add-prefix check-valgrind-,$(valgrind_tools))
 ']
 
+	AS_IF([test "$enable_valgrind" != "yes"], [
+		VALGRIND_CHECK_RULES='
+check-valgrind:
+	@echo "Need to use GNU make and reconfigure with --enable-valgrind"'
+	])
+
 	AC_SUBST([VALGRIND_CHECK_RULES])
 	m4_ifdef([_AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE([VALGRIND_CHECK_RULES])])
 ])