fsm.c: Print error message for FSM with allstate_action but no events

As suggested by Vadim while reviewing a related fix for ipa_keepalive.c
in libosmo-abis (see https://gerrit.osmocom.org/#/c/libosmo-abis/+/13540/),
it makes sense to print an error message if anyone registers a FSM
that specifies an allstate_action callback but at the same time no
events that would ever end up in that callback.

Change-Id: I9e73f7363ab15a00843e3f0d1e5776f4be7ebc46

1 files changed, 11 insertions, 0 deletions

diff --git a/src/fsm.c b/src/fsm.c
index 337786d9..04c583b0 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -256,6 +256,17 @@ int osmo_fsm_register(struct osmo_fsm *fsm)
 		return -EEXIST;
 	if (fsm->event_names == NULL)
 		LOGP(DLGLOBAL, LOGL_ERROR, "FSM '%s' has no event names! Please fix!\n", fsm->name);
+
+	if (fsm->allstate_action && !fsm->allstate_event_mask) {
+		LOGP(DLGLOBAL, LOGL_ERROR, "FSM '%s' has allstate_action but no allstate_event_mask\n",
+			fsm->name);
+	}
+
+	if (!fsm->allstate_action && fsm->allstate_event_mask) {
+		LOGP(DLGLOBAL, LOGL_ERROR, "FSM '%s' has allstate_event_mask but no allstate_action\n",
+			fsm->name);
+	}
+
 	llist_add_tail(&fsm->list, &osmo_g_fsms);
 	INIT_LLIST_HEAD(&fsm->instances);