target thumb C: libexosip <= external/libexosip/src/eXregister_api.c

external/libexosip/src/eXregister_api.c: In function '_eXosip_register_build_register':

external/libexosip/src/eXregister_api.c:163: warning: implicit declaration of function 'atoi'

target thumb C: libexosip <= external/libexosip/src/eXsubscription_api.c

external/libexosip/src/eXsubscription_api.c: In function '_eXosip_subscribe_send_request_with_credential':

解决方法：

找到atoi的头文件，加到代码中就可以了