rename STATS to LWIP_STATS and make it checked by #if not #ifdef.The rest of the _STATS defines should follow

src/core/stats.c

@@ -39,15 +39,13 @@
 #include "lwip/mem.h"
 
 
-#ifdef STATS
+#if LWIP_STATS
 struct stats_ lwip_stats;
-#endif /* STATS */
 /*-----------------------------------------------------------------------------------*/
 void
 stats_init(void)
 {
-#ifdef STATS
   memset(&lwip_stats, 0, sizeof(struct stats_));
-#endif /* STATS */
 }
+#endif /* LWIP_STATS */
 /*-----------------------------------------------------------------------------------*/

src/include/lwip/dhcp.h

@@ -87,9 +87,6 @@ PACK_STRUCT_END
 #  include "arch/epstruct.h"
 #endif
 
-/* Declare here to avoid including netif.h creating a circular dependency */
-//struct netif;
-
 /** start DHCP configuration */
 err_t dhcp_start(struct netif *netif);
 /** stop DHCP configuration */

src/include/lwip/opt.h

@@ -297,9 +297,12 @@ a lot of data that needs to be copied, this should be set high. */
 #endif
 
 /* ---------- Statistics options ---------- */
-#define STATS
+#ifndef LWIP_STATS
+#define LWIP_STATS	1
+#endif
+
+#if LWIP_STATS
 
-#ifdef STATS
 #define LINK_STATS
 #define IP_STATS
 #define ICMP_STATS
@@ -309,7 +312,8 @@ a lot of data that needs to be copied, this should be set high. */
 #define MEMP_STATS
 #define PBUF_STATS
 #define SYS_STATS
-#endif /* STATS */
+
+#endif /* LWIP_STATS */
 
 /* Debugging options all default to off */
 

src/include/lwip/stats.h

@@ -38,7 +38,7 @@
 #include "lwip/mem.h"
 #include "lwip/memp.h"
 
-#ifdef STATS
+#if LWIP_STATS
 
 struct stats_proto {
   u16_t xmit;    /* Transmitted packets. */
@@ -99,9 +99,11 @@ struct stats_ {
 
 extern struct stats_ lwip_stats;
 
-#endif /* STATS */
 
 void stats_init(void);
+#else
+#define stats_init()
+#endif /* LWIP_STATS */
 #endif /* __LWIP_STATS_H__ */