vl: handle -object help

List the user creatable objects.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

vl.c

@@ -2698,6 +2698,19 @@ static int machine_set_property(void *opaque,
  */
 static bool object_create_initial(const char *type)
 {
+    if (is_help_option(type)) {
+        GSList *l, *list;
+
+        printf("List of user creatable objects:\n");
+        list = object_class_get_list_sorted(TYPE_USER_CREATABLE, false);
+        for (l = list; l != NULL; l = l->next) {
+            ObjectClass *oc = OBJECT_CLASS(l->data);
+            printf("%s\n", object_class_get_name(oc));
+        }
+        g_slist_free(list);
+        exit(0);
+    }
+
     if (g_str_equal(type, "rng-egd") ||
         g_str_has_prefix(type, "pr-manager-")) {
         return false;