| Haibo Huang | b0bee82 | 2021-02-24 15:40:15 -0800 | [diff] [blame^] | 1 | ***NOTE*** |
| 2 | |
| 3 | If you get linker errors about undefined references to symbols that involve types in the `std::__cxx11` namespace or the tag |
| 4 | `[abi:cxx11]` then it probably indicates that you are trying to link together object files that were compiled with different |
| 5 | values for the _GLIBCXX_USE_CXX11_ABI marco. This commonly happens when linking to a third-party library that was compiled with |
| 6 | an older version of GCC. If the third-party library cannot be rebuilt with the new ABI, then you need to recompile your code with |
| 7 | the old ABI,just like: |
| 8 | **g++ stringWrite.cpp -ljsoncpp -std=c++11 -D_GLIBCXX_USE_CXX11_ABI=0 -o stringWrite** |
| 9 | |
| 10 | Not all of uses of the new ABI will cause changes in symbol names, for example a class with a `std::string` member variable will |
| 11 | have the same mangled name whether compiled with the older or new ABI. In order to detect such problems, the new types and functions |
| 12 | are annotated with the abi_tag attribute, allowing the compiler to warn about potential ABI incompatibilities in code using them. |
| 13 | Those warnings can be enabled with the `-Wabi-tag` option. |