我在使用海思硬件接口的时候，用到了mpi库，然后Makefile里面链接了这个库，但是编译到了链接的时候报错了：
./lib//libmpi.so: undefined reference to `sem_post\' ./lib//libmpi.so: undefined reference to `snprintf_s\' ./lib//libmpi.so: undefined reference to `sincos\' ./lib//libmpi.so: undefined reference to `HI_DNVQE_ReadFrame\' ./lib//libmpi.so: undefined reference to `HI_VOICE_EncodeFrame\' ./lib//libmpi.so: undefined reference to `atan2\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_Create\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_SetVolume\' ./lib//libmpi.so: undefined reference to `sem_trywait\' ./lib//libmpi.so: undefined reference to `acos\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_GetVolume\' ./lib//libmpi.so: undefined reference to `HI_VOICE_DecReset\' ./lib//libmpi.so: undefined reference to `HI_DNVQE_WriteFrame\' ./lib//libmpi.so: undefined reference to `HI_DNVQE_Create\' ./lib//libmpi.so: undefined reference to `sin\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_Destroy\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_GetConfig\' ./lib//libmpi.so: undefined reference to `sem_getvalue\' ./lib//libmpi.so: undefined reference to `sem_wait\' ./lib//libmpi.so: undefined reference to `HI_VOICE_EncReset\' ./lib//libmpi.so: undefined reference to `sem_init\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_ReadFrame\' ./lib//libmpi.so: undefined reference to `memcpy_s\' ./lib//libmpi.so: undefined reference to `tan\' ./lib//libmpi.so: undefined reference to `HI_UPVQE_WriteFrame\' ./lib//libmpi.so: undefined reference to `memmove_s\' ./lib//libmpi.so: undefined reference to `pthread_join\' ./lib//libmpi.so: undefined reference to `HI_VOICE_DecodeFrame\' ./lib//libmpi.so: undefined reference to `pthread_create\' ./lib//libmpi.so: undefined reference to `pow\' ./lib//libmpi.so: undefined reference to `round\' ./lib//libmpi.so: undefined reference to `log10\' ./lib//libmpi.so: undefined reference to `HI_DNVQE_GetConfig\' ./lib//libmpi.so: undefined reference to `sqrt\' ./lib//libmpi.so: undefined reference to `sem_destroy\' ./lib//libmpi.so: undefined reference to `memset_s\' ./lib//libmpi.so: undefined reference to `strncpy_s\' ./lib//libmpi.so: undefined reference to `HI_DNVQE_Destroy\'
这些信号相关的函数链接pthread库，HI_*相关的接口去文档查属于哪个库，或许我的文档跟当前开发板不匹配，我连续找了三个没找到，不过这么火的芯片别人肯定也用过，所以方案一直接上网搜该函数；方案二我有一份领导给的头文件和库文件，我到整个头文件里面能找到相应的函数，然后就去把名字差不多的库文件链接进去，果然编译通过了。还有要特别注意的是基础库要靠右侧。最后，strncpy_s等几个函数海思有自己的实现，在库libsecurec.so（或静态库libsecurec.a）里面，这个基础库要靠右侧放。
附上自己的Makefile吧，省得下次忘记了
CC = arm-himix200-linux-gcc CCFLAGS = -Wall -O -g INCLUDE = -I ./include # 可执行文件的名字 TARGET = encJpeg # 链接 libmpi.a等库文件 LIBPATH = -L ./lib/ LIBNAME = -lmpi -live -lupvqe -ldnvqe -lVoiceEngine -lpthread -lsecurec #正则表达式表示目录下所有.c文件， C_SRCS= $(wildcard ./src/*.c) # 第一行依赖关系：冒号后面为依赖的文件 # 第二行规则：$@表示目标文件，$^表示所有依赖文件，$<表示第一个依赖文件 $(TARGET): $(C_SRCS) $(CC) $(CCFLAGS) $(INCLUDE) $(LIBPATH) $(LIBNAME) -o ./build/$@ $^ # make clean删除所有.o和目标文件 clean: rm -f ./build/*