build: add -Wimplicit-fallthrough

Also:
- replace all /* fallthrough */ comments with portable fallthrough;
pseudo keyword to accomodate both gcc and clang
- add missing break; statements as required by older versions of gcc
- cleanup some code to remove unnecessary fallthrough

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>

3 files changed, 6 insertions, 15 deletions

diff --git a/ldpd/init.c b/ldpd/init.c
index f0cb98e5c..c34d18f8b 100644
--- a/ldpd/init.c
+++ b/ldpd/init.c
@@ -229,7 +229,7 @@ send_capability(struct nbr *nbr, uint16_t capability, int enable)
 		 * Announcement Parameter in Capability messages sent to
 		 * its peers".
 		 */
-		/* FALLTHROUGH */
+		fallthrough;
 	default:
 		fatalx("send_capability: unsupported capability");
 	}
@@ -333,7 +333,7 @@ recv_capability(struct nbr *nbr, char *buf, uint16_t len)
 			 * parameter and process any other Capability Parameters
 			 * in the message".
 			 */
-			/* FALLTHROUGH */
+			fallthrough;
 		default:
 			if (!CHECK_FLAG(ntohs(tlv.type), UNKNOWN_FLAG))
 				send_notification_rtlvs(nbr, S_UNSSUPORTDCAP,
diff --git a/ldpd/ldp_vty_exec.c b/ldpd/ldp_vty_exec.c
index 906b5c1bf..f3bcd1b25 100644
--- a/ldpd/ldp_vty_exec.c
+++ b/ldpd/ldp_vty_exec.c
@@ -1106,7 +1106,7 @@ show_lib_msg(struct vty *vty, struct imsg *imsg, struct show_params *params)
 		if (params->lib.remote_label != NO_LABEL &&
 		    params->lib.remote_label != rt->remote_label)
 			return (0);
-		/* FALLTHROUGH */
+		fallthrough;
 	case IMSG_CTL_SHOW_LIB_RCVD:
 		rt = imsg->data;
 
diff --git a/ldpd/neighbor.c b/ldpd/neighbor.c
index 5209c55bb..d40728b04 100644
--- a/ldpd/neighbor.c
+++ b/ldpd/neighbor.c
@@ -505,21 +505,12 @@ nbr_start_idtimer(struct nbr *nbr)
 {
 	int	secs;
 
-	secs = INIT_DELAY_TMR;
-	switch(nbr->idtimer_cnt) {
-	default:
+	if (nbr->idtimer_cnt > 2) {
 		/* do not further increase the counter */
 		secs = MAX_DELAY_TMR;
-		break;
-	case 2:
-		secs *= 2;
-		/* FALLTHROUGH */
-	case 1:
-		secs *= 2;
-		/* FALLTHROUGH */
-	case 0:
+	} else {
+		secs = INIT_DELAY_TMR * (1 << nbr->idtimer_cnt);
 		nbr->idtimer_cnt++;
-		break;
 	}
 
 	EVENT_OFF(nbr->initdelay_timer);