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/pbuf.c

@@ -61,9 +61,8 @@
  *
  */
 
-#include <string.h>
-
 #include "lwip/opt.h"
+
 #include "lwip/stats.h"
 #include "lwip/def.h"
 #include "lwip/mem.h"
@@ -72,6 +71,8 @@
 #include "lwip/sys.h"
 #include "arch/perf.h"
 
+#include <string.h>
+
 #define SIZEOF_STRUCT_PBUF        LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
 /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
    aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */