Minor changes (but in lot of files): add #if/#endif for options where they could miss. #if LWIP_xxx if always put after #include "lwip/opt.h" (note this one indirectly include cc.h). Move others includes inside #if/#endif block.

src/core/ipv4/autoip.c

@@ -62,8 +62,10 @@
  *
  */
 
-#include <stdlib.h>
-#include <string.h>
+#include "lwip/opt.h"
+
+#if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
+
 #include "lwip/mem.h"
 #include "lwip/udp.h"
 #include "lwip/ip_addr.h"
@@ -71,7 +73,8 @@
 #include "lwip/autoip.h"
 #include "netif/etharp.h"
 
-#if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
+#include <stdlib.h>
+#include <string.h>
 
 /* pseudo random macro based on netif informations. You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
 #ifndef LWIP_AUTOIP_RAND

src/core/ipv4/icmp.c

@@ -39,9 +39,10 @@
 /* Some ICMP messages should be passed to the transport protocols. This
    is not implemented. */
 
-#include <string.h>
-
 #include "lwip/opt.h"
+
+#if LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
+
 #include "lwip/icmp.h"
 #include "lwip/inet.h"
 #include "lwip/ip.h"
@@ -49,7 +50,7 @@
 #include "lwip/stats.h"
 #include "lwip/snmp.h"
 
-#if LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
+#include <string.h>
 
 /**
  * Processes ICMP input packets, called from ip_input().

src/core/ipv4/igmp.c

@@ -77,6 +77,10 @@ Steve Reynolds
  * Includes
  *----------------------------------------------------------------------------*/
 
+#include "lwip/opt.h"
+
+#if LWIP_IGMP /* don't build if not configured for use in lwipopts.h */
+
 #include "lwip/debug.h"
 #include "lwip/def.h"
 #include "lwip/mem.h"
@@ -89,12 +93,8 @@ Steve Reynolds
 #include "lwip/stats.h"
 #include "lwip/igmp.h"
 
-#include "arch/perf.h"
-
 #include "string.h"
 
-#if LWIP_IGMP /* don't build if not configured for use in lwipopts.h */
-
 /*-----------------------------------------------------------------------------
  * Globales
  *----------------------------------------------------------------------------*/

src/core/ipv4/ip.c

@@ -39,7 +39,6 @@
  */
 
 #include "lwip/opt.h"
-
 #include "lwip/def.h"
 #include "lwip/mem.h"
 #include "lwip/ip.h"
@@ -47,22 +46,14 @@
 #include "lwip/inet.h"
 #include "lwip/netif.h"
 #include "lwip/icmp.h"
+#include "lwip/igmp.h"
 #include "lwip/raw.h"
 #include "lwip/udp.h"
 #include "lwip/tcp.h"
-
-#include "lwip/stats.h"
-
-#include "arch/perf.h"
-
 #include "lwip/snmp.h"
-#if LWIP_DHCP
-#  include "lwip/dhcp.h"
-#endif /* LWIP_DHCP */
-
-#if LWIP_IGMP
-#  include "lwip/igmp.h"
-#endif /* LWIP_IGMP */
+#include "lwip/dhcp.h"
+#include "lwip/stats.h"
+#include "arch/perf.h"
 
 /**
  * Initializes the IP layer.

src/core/ipv4/ip_addr.c

@@ -36,6 +36,7 @@
  *
  */
 
+#include "lwip/opt.h"
 #include "lwip/ip_addr.h"
 #include "lwip/inet.h"
 #include "lwip/netif.h"

src/core/ipv4/ip_frag.c

@@ -37,8 +37,6 @@
  * 
  */
 
-#include <string.h>
-
 #include "lwip/opt.h"
 #include "lwip/ip.h"
 #include "lwip/ip_frag.h"
@@ -46,6 +44,8 @@
 #include "lwip/snmp.h"
 #include "lwip/stats.h"
 
+#include <string.h>
+
 #if IP_REASSEMBLY
 static u8_t ip_reassbuf[IP_HLEN + IP_REASS_BUFSIZE];
 static u8_t ip_reassbitmap[IP_REASS_BUFSIZE / (8 * 8) + 1];