+# ------------------------------------------------------------------------------
+
+AC_ARG_ENABLE([debug],
+ AS_HELP_STRING([--enable-debug], [enable debug messages @<:@default=disabled@:>@]),
+ [], [enable_debug=no])
+AS_IF([test "x$enable_debug" = "xyes"], [
+ AC_DEFINE(ENABLE_DEBUG, [1], [Debug messages.])
+])
+