undefined reference to `FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)'

记一次undefined reference排查

一、背景：

1. 编译模块A，三部曲通过
2. 编译模块B（依赖模块A），报错：
   /usr/bin/ld: OrkAudio.o: in function Transcode(CStdStr<char>&):
/home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:173:
undefined reference to FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)
/usr/bin/ld: /home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:175: undefined reference to FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)
/usr/bin/ld: /home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:177:
undefined reference to FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)
/usr/bin/ld: /home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:179: undefined reference to FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)
/usr/bin/ld: /home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:181: undefined reference to FilterRegistry::RegisterFilter(std::shared_ptr<Filter>&)
/usr/bin/ld: OrkAudio.o:/home/lings/GitSpace/oreka/orkaudio/OrkAudio.cpp:183:

二、排查

1. 查看A模块里面的方法：
   nm /usr/lib/liborkbase.so |grep FilterRegistry
2. 得到的结果如下：
   000000000004ecd0 T _ZN14FilterRegistry14RegisterFilterERN5boost10shared_ptrI6FilterEE
3. 乍一看没问题，仔细看入参的指针类型不一样！
4. 模块A里的是boost::shared_ptr
5. 模块B里的入参是std::shared_ptr

三、解决

1. 源代码里确实允许使用两种
   #ifdef SUPPORTS_CPP11
#include <memory>
namespace oreka {
using std::shared_ptr;
using std::make_shared;
using std::weak_ptr;
};
#else
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
#include <boost/weak_ptr.hpp>
namespace oreka {
using boost::shared_ptr;
using boost::make_shared;
using boost::weak_ptr;
};
#endif
2. 而B模块编译的时候Makefile文件中指定了CPP11
   CXXFLAGS = -std=c++11 -g -O2 -fno-inline-functions -std=c++11 -DSUPPORTS_CPP11 -fPIC
3. 去掉B模块指定的-DSUPPORTS_CPP11即可。