Boost.Python和CMake链接和加载错误

Question

我main.cpp喜欢这样:

#include <boost/python.hpp>

const char* greeting()
{
    return "Hello world?";
}

BOOST_PYTHON_MODULE(test)
{
    using namespace boost::python;

    def("greeting", greeting);
}

和一个CMakeLists.txt文件:

project(test)
cmake_minimum_required(VERSION 2.8)

# get boost
set(Boost_USE_STATIC_LIBS   ON)
set(Boost_USE_MULTITHREADED ON)
find_package(Boost COMPONENTS
                system
                thread
                python
             REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARY_DIRS})

# get python
find_package(PythonLibs REQUIRED)
include_directories(${PYTHON_INCLUDE_DIRS})
link_directories(${PYTHON_LIBRARIES})

add_library(test SHARED
        main.cpp
    )

我可以跑cmake,make也很好.它libtest.so为我输出一个漂亮的小文件.为了测试它,我有一个像这样的Python脚本:

import libtest

print(libtest.greeting())

在同一目录中运行它libtest.so会产生以下错误:

Traceback (most recent call last):
  File "test.py", line 1, in <module>
    import libtest
ImportError: /home/travis/projects/boost-python-test/build/libtest.so: undefined symbol: _ZNK5boost6python7objects21py_function_impl_base9max_arityEv

哎呀!问题非常清楚make VERBOSE=1......创建我的行libtest.so看起来像这样:

/usr/bin/c++  -fPIC   -shared -Wl,-soname,libtest.so -o libtest.so CMakeFiles/test.dir/main.cpp.o -L/usr/lib/libpython2.7.so

我有一个心理障碍,为什么我看不到-L/usr/lib/libboost_python-mt-py27.a那条线.它显然有效find_package(PythonLibs ...).由于一些CMake的新生儿,我不及格.

Answer 1

对此的解决方案非常简单.必须在声明target_link_libraries 之后明确地链接库add_library.

target_link_libraries(test
        ${Boost_LIBRARIES}
        ${PYTHON_LIBRARIES}
    )

我还不确定为什么它没有那个适用于Python.魔法？