From 44f7cb712cb2b6892cb1596a3d3d9e37e0de5448 Mon Sep 17 00:00:00 2001
From: Jose Alamos <jose.alamos@haw-hamburg.de>
Date: Tue, 17 Mar 2020 12:32:34 +0100
Subject: [PATCH] gnrc_netif: add GNRC_NETIF_SINGLE macro

---
 sys/include/net/gnrc/netif/conf.h | 12 ++++++++++++
 sys/net/gnrc/netif/gnrc_netif.c   |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/sys/include/net/gnrc/netif/conf.h b/sys/include/net/gnrc/netif/conf.h
index 916f823501..b5ddb6c1f5 100644
--- a/sys/include/net/gnrc/netif/conf.h
+++ b/sys/include/net/gnrc/netif/conf.h
@@ -29,6 +29,18 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Single interface optimizations
+ *
+ *          Define to 1 to allow GNRC optimizations when only one interface
+ *          is available.
+ *
+ * @note    This MUST NOT be enabled if there's more than one interface.
+ */
+#if DOXYGEN
+#define GNRC_NETIF_SINGLE
+#endif
+
 /**
  * @brief   Default priority for network interface threads
  */
diff --git a/sys/net/gnrc/netif/gnrc_netif.c b/sys/net/gnrc/netif/gnrc_netif.c
index 7b972a9027..090fa02d12 100644
--- a/sys/net/gnrc/netif/gnrc_netif.c
+++ b/sys/net/gnrc/netif/gnrc_netif.c
@@ -49,9 +49,9 @@ int gnrc_netif_create(gnrc_netif_t *netif, char *stack, int stacksize, char prio
 {
     int res;
 
-    if (IS_ACTIVE(DEVELHELP) && IS_ACTIVE(GNRC_NETIF_SINGLE) && netif_iter(NULL)) {
-        LOG_WARNING("gnrc_netif: GNRC_NETIF_SINGLE set but more than one "
-                    "interface is being registered.");
+    if (IS_ACTIVE(DEVELHELP) && gnrc_netif_highlander() && netif_iter(NULL)) {
+        LOG_WARNING("gnrc_netif: gnrc_netif_highlander() returned true but "
+                    "more than one interface is being registered.\n");
         assert(netif_iter(NULL) == NULL);
     }
     rmutex_init(&netif->mutex);