C++ ABI：编译报错之：gcc 4.8.1 切 gcc 6.1.0

1.问题背景

新建了个小项目，换了个编译环境，发现依赖库拷贝过来后，编译报错。编译器有差别：

• 原来是 gcc 4.8.1
• 新的环境是 gcc 6.1.0
  没想那么多，就是试着编译一下。总的还行，但是最后连接时，报错如下：

不要问为啥用这么老的编译器，在需求的环境是这样的。

kafkaproducer.o: In function `KafkaProducer::Start()':
/path/to/src/kafkaproducer.cpp:58: undefined reference to `RdKafka::Producer::create(RdKafka::Conf*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)'       
/path/to/src/kafkaproducer.cpp:68: undefined reference to `RdKafka::Topic::create(RdKafka::Handle*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, RdKafka::Conf*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)'
kafkaproducer.o: In function `KafkaProducer::Produce(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char const*, int)':
/path/to/src/kafkaproducer.cpp:88: undefined reference to `RdKafka::err2str[abi:cxx11](RdKafka::ErrorCode)'
kafkaconsumer.o: In function `KafkaConsumer::Start()':
/path/to/src/kafkaconsumer.cpp:157: undefined reference to `RdKafka::KafkaConsumer::create(RdKafka::Conf*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)' 
/path/to/src/kafkaconsumer.cpp:172: undefined reference to `RdKafka::err2str[abi:cxx11](RdKafka::ErrorCode)'
kafkaconsumer.o: In function `KafkaConsumer::HandleMsg(char const*, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned int)':
/path/to/src/kafkaconsumer.cpp:275: undefined reference to `splitvector(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int)'
collect2: error: ld returned 1 exit status
make: *** [wd_svr] Error 1

排查与解决

其实上面的一大坨，看着挺有点摸不着头脑的。但是吧，静下心来，排除了可能的kafka库的连接问题后，直觉上发现个关键词：

std::__cxx11::basic_string

搜索后，发现是跟ABI有关，加上编译宏以后可以正常编译通过。

参考：C++ ABI 问题定位解决 https://zhuanlan.zhihu.com/p/125197727

还未完全掌握，后续需要再系统补充下该知识点。