added MEMP_MEM_MALLOC to use mem_malloc/mem_free instead of the pool allocator (can save code size with MEM_LIBC_MALLOC if libc-malloc is otherwise used)

src/include/lwip/memp.h

@@ -73,10 +73,22 @@ typedef enum {
    We use this helper type and these defines so we can avoid using const memp_t values */
 #define MEMP_POOL_FIRST ((memp_t) MEMP_POOL_HELPER_FIRST)
 #define MEMP_POOL_LAST   ((memp_t) MEMP_POOL_HELPER_LAST)
-
-extern const u16_t memp_sizes[MEMP_MAX];
 #endif /* MEM_USE_POOLS */
 
+#if MEMP_MEM_MALLOC || MEM_USE_POOLS
+extern const u16_t memp_sizes[MEMP_MAX];
+#endif /* MEMP_MEM_MALLOC || MEM_USE_POOLS */
+
+#if MEMP_MEM_MALLOC
+
+#include "mem.h"
+
+#define memp_init()
+#define memp_malloc(type)     mem_malloc(memp_sizes[type])
+#define memp_free(type, mem)  mem_free(mem)
+
+#else /* MEMP_MEM_MALLOC */
+
 void  memp_init(void);
 
 #if MEMP_OVERFLOW_CHECK
@@ -87,6 +99,8 @@ void *memp_malloc(memp_t type);
 #endif
 void  memp_free(memp_t type, void *mem);
 
+#endif /* MEMP_MEM_MALLOC */
+
 #ifdef __cplusplus
 }
 #endif

src/include/lwip/opt.h

@@ -98,6 +98,15 @@
 #define MEM_LIBC_MALLOC                 0
 #endif
 
+/**
+* MEMP_MEM_MALLOC==1: Use mem_malloc/mem_free instead of the lwip pool allocator.
+* Especially useful with MEM_LIBC_MALLOC but handle with care regarding execution
+* speed and usage from interrupts!
+*/
+#ifndef MEMP_MEM_MALLOC
+#define MEMP_MEM_MALLOC                 0
+#endif
+
 /**
  * MEM_ALIGNMENT: should be set to the alignment of the CPU
  *    4 byte alignment -> #define MEM_ALIGNMENT 4
@@ -1120,7 +1129,7 @@
  */
 #ifndef RECV_BUFSIZE_DEFAULT
 #define RECV_BUFSIZE_DEFAULT            INT_MAX
-#endif /* RECV_BUFSIZE_DEFAULT */
+#endif
 
 /**
  * SO_REUSE==1: Enable SO_REUSEADDR and SO_REUSEPORT options. DO NOT USE!