LWIP_ERROR("tcp_connect: can only connect from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
#ifndef LWIP_PLATFORM_ASSERT
#define LWIP_PLATFORM_ASSERT(x) do { if(!(x)) while(1); } while(0)
#endif
#ifndef LWIP_NOASSERT
#define LWIP_ASSERT(message, assertion) do { if(!(assertion)) \
#define LWIP_ERROR(message, expression, handler) do { if (!(expression)) { \
LWIP_PLATFORM_ASSERT(message);\
handler;}} while(0)
#endif /* LWIP_ERROR */
原文:https://www.cnblogs.com/jieruishu/p/9246749.html