Fix cyclic dependencies by careful re-ordering of #includes.

This is really nasty. Can we forward-declare pointers to structs?

src/include/ipv4/lwip/icmp.h

@@ -37,6 +37,7 @@
 #include "lwip/opt.h"
 #include "lwip/pbuf.h"
 
+#include "lwip/ip_addr.h"
 #include "lwip/netif.h"
 
 #define ICMP_ER 0      /* echo reply */

src/include/ipv4/lwip/ip_addr.h

@@ -34,6 +34,28 @@
 
 #include "lwip/arch.h"
 
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct ip_addr {
+  PACK_STRUCT_FIELD(u32_t addr);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+/* For compatibility with BSD code */
+struct in_addr {
+  u32_t s_addr;
+};
+
+#include "lwip/netif.h"
+
+extern const struct ip_addr ip_addr_any;
+extern const struct ip_addr ip_addr_broadcast;
+
 /** IP_ADDR_ can be used as a fixed IP address
  *  for the wildcard and the broadcast address
  */
@@ -76,25 +98,6 @@
 
 #define IN_LOOPBACKNET      127         /* official! */
 
-#ifdef PACK_STRUCT_USE_INCLUDES
-#  include "arch/bpstruct.h"
-#endif
-PACK_STRUCT_BEGIN
-struct ip_addr {
-  PACK_STRUCT_FIELD(u32_t addr);
-} PACK_STRUCT_STRUCT;
-PACK_STRUCT_END
-#ifdef PACK_STRUCT_USE_INCLUDES
-#  include "arch/epstruct.h"
-#endif
-
-/* For compatibility with BSD code */
-struct in_addr {
-  u32_t s_addr;
-};
-
-extern const struct ip_addr ip_addr_any;
-extern const struct ip_addr ip_addr_broadcast;
 
 #define IP4_ADDR(ipaddr, a,b,c,d) (ipaddr)->addr = htonl(((u32_t)(a & 0xff) << 24) | ((u32_t)(b & 0xff) << 16) | \
                                                          ((u32_t)(c & 0xff) << 8) | (u32_t)(d & 0xff))
@@ -110,13 +113,13 @@ extern const struct ip_addr ip_addr_broadcast;
 
 #define ip_addr_isany(addr1) ((addr1) == NULL || (addr1)->addr == 0)
 
-#if 1 /* replaced by function in ip_addr.c */
+#if 0 /* replaced by function in ip_addr.c */
 #define ip_addr_isbroadcast(addr1, mask) (((((addr1)->addr) & ~((mask)->addr)) == \
            (0xffffffff & ~((mask)->addr))) || \
                                          ((addr1)->addr == 0xffffffff) || \
                                          ((addr1)->addr == 0x00000000))
 #else
-u8_t ip_addr_isbroadcast(struct ip_addr *addr, struct netif *netif);
+u8_t ip_addr_isbroadcast(struct ip_addr *, struct netif *);
 #endif
 
 #define ip_addr_ismulticast(addr1) (((addr1)->addr & ntohl(0xf0000000)) == ntohl(0xe0000000))

src/include/lwip/netif.h

@@ -40,7 +40,9 @@
 
 #include "lwip/inet.h"
 #include "lwip/pbuf.h"
-#include "lwip/dhcp.h"
+#if LWIP_DHCP
+#  include "lwip/dhcp.h"
+#endif
 
 /** must be the maximum of all used hardware address lengths
     across all types of interfaces in use */