无法从谷歌协议缓冲区编译示例

Question

我寻求其他主题,但他们不帮我=(.在我的工作服务器上,我没有sudo特权,所以我安装PB与

./configure --prefix =/home/username/local

然后我用"person"示例创建源文件,并使用protoc成功编译它.

我没有pkg-info =(.我尝试用它编译它

g ++ -I/home/username/local/include -L/home/username/local/lib -lprotobuf -lpthread main.cpp person.pb.cc

然后有十亿个类似错误,即

person.pb.cc:(.text+0x4cf):未定义引用`google :: protobuf :: internal :: kEmptyString'

我认为,这是一个链接问题,但如何解决呢？

echo $ LD_LIBRARY_PATH/home/username/local/lib

在main.cpp中:

#include "person.pb.h"
...

谢谢.

Answer 1

把图书馆放在最后:

g ++ -I/home/username/local/include -L/home/username/local/lib main.cpp person.pb.cc -lprotobuf -pthread

来自GCC链接选项:

-llibrary
-l library
    Search the library named library when linking. 
    (The second alternative with the library as a separate argument
    is only for POSIX compliance and is not recommended.)

    It makes a difference where in the command you write this option;
    the linker searches and processes libraries and object files in the
    order they are specified.
    Thus, `foo.o -lz bar.o' searches library `z' after file foo.o but
    before bar.o. If bar.o refers to functions in `z', those functions
    may not be loaded.

此外,使用-pthread,而不是-lpthread作为-pthread可用于预处理器和连接设置标志.