Boost.Python 模块中未定义的符号

我正在尝试使用 Boost.Python 为模板库的某个实例构建一个小型 Python 扩展。该库广泛使用 CGAL 库，它与 CMake 集成得相当好，因此我将其用于我的项目。

这是我的模块的代码（python_export.cpp）：

#include <boost/python.hpp>
#include <CGAL/Exact_spherical_kernel_3.h>
#include "Sphere_intersecter.h" // header-only

typedef CGAL::Exact_spherical_kernel_3 SK;
template class Sphere_intersecter<SK>; // explicit for "-fno-implicit-templates"
typedef Sphere_intersecter<SK> SI;

BOOST_PYTHON_MODULE(thickness_diag)
{
    using namespace boost::python;
    class_<SI>("SphereIntersecter", no_init)
        .def("add_sphere", &SI::add_sphere)
    ;
}

和 CMakeLists.txt：

cmake_minimum_required(VERSION 2.6.2)
project(ThicknessDiag-Python)

# CGAL
find_package(CGAL REQUIRED)
include(${CGAL_USE_FILE})

# Boost
find_package(Boost REQUIRED COMPONENTS python)
find_package(PythonLibs 2.7 REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})
include_directories(${PYTHON_INCLUDE_DIRS})

# Shared library
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-implicit-templates")
set(ThicknessDiag-Python "thickness_diag")
add_library(${ThicknessDiag-Python} SHARED python_export.cpp)
set_target_properties(${ThicknessDiag-Python} PROPERTIES PREFIX "")
target_link_libraries(${ThicknessDiag-Python}
    ${PYTHON_LIBRARIES} ${Boost_LIBRARIES}
    ${CGAL_LIBRARIES} ${CGAL_3RD_PARTY_LIBRARIES})

编译命令的详细输出：

[100%] Building CXX object CMakeFiles/thickness_diag.dir/python_export.cpp.o
/usr/bin/c++ -Dthickness_diag_EXPORTS -DCGAL_USE_MPFR -DCGAL_USE_GMP -frounding-math -fno-implicit-templates -O3 -DNDEBUG -fPIC -isystem /usr/local/include -I/usr/include/python2.7 -o CMakeFiles/thickness_diag.dir/python_export.cpp.o -c /home/jmcomets/ThicknessDiag/tests/python_export.cpp
Linking CXX shared library thickness_diag.so
/usr/bin/c++ -fPIC -frounding-math -fno-implicit-templates -O3 -DNDEBUG -shared -Wl,-soname,thickness_diag.so -o thickness_diag.so CMakeFiles/thickness_diag.dir/python_export.cpp.o -L/usr/local/lib -lmpfr -lgmp /usr/local/lib/libCGAL.so /usr/local/lib/libboost_thread.so -lpthread /usr/local/lib/libboost_system.so -lpython2.7 /usr/local/lib/libboost_python.so /usr/local/lib/libCGAL.so /usr/local/lib/libboost_thread.so -lpthread /usr/local/lib/libboost_system.so -lpython2.7 /usr/local/lib/libboost_python.so -Wl,-rpath,/usr/local/lib 

导入共享库的输出：

$ python -c 'import thickness_diag'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: ./thickness_diag.so: undefined symbol: _ZN5boost6python9converter6detail15registered_baseIRVK18Sphere_intersecterIN4CGAL18Spherical_kernel_3INS5_9CartesianINS5_4GmpqEEENS5_32Algebraic_kernel_for_spheres_2_3IS8_EEEEEE10convertersE
$ nm thickness_diag.so | grep _ZN5boost6python9converter6detail15registered_baseIRVK18Sphere_intersecterIN4CGAL18Spherical_kernel_3INS5_9CartesianINS5_4GmpqEEENS5_32Algebraic_kernel_for_spheres_2_3IS8_EEEEEE10convertersE
                 U _ZN5boost6python9converter6detail15registered_baseIRVK18Sphere_intersecterIN4CGAL18Spherical_kernel_3INS5_9CartesianINS5_4GmpqEEENS5_32Algebraic_kernel_for_spheres_2_3IS8_EEEEEE10convertersE

这两天我一直在努力解决这个问题，任何帮助都会很棒！ :)

编辑：ldd 的输出

$ ldd thickness_diag.so
    linux-vdso.so.1 =>  (0x00007fffdfdff000)
    libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007fd91eadf000)
    libCGAL.so.10 => /usr/local/lib/libCGAL.so.10 (0x00007fd91e8b4000)
    libboost_thread.so.1.55.0 => /usr/local/lib/libboost_thread.so.1.55.0 (0x00007fd91e699000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fd91e47c000)
    libboost_system.so.1.55.0 => /usr/local/lib/libboost_system.so.1.55.0 (0x00007fd91e278000)
    libpython2.7.so.1.0 => /usr/lib/libpython2.7.so.1.0 (0x00007fd91dd79000)
    libboost_python.so.1.55.0 => /usr/local/lib/libboost_python.so.1.55.0 (0x00007fd91db2c000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fd91d829000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fd91d612000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fd91d253000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fd91cf57000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fd91cd4e000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fd91ef85000)
    libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fd91cb37000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fd91c933000)
libutil.so.1 => /lib/x86_64-linux-gnu/libutil.so.1 (0x00007fd91c72f000)

好吧，我想通了。事实证明该选项-fno-implicit-templates阻止 boost 进行正常的模板实例化（这实际上非常明显）。

然后我又发现了一个我认为已经修复的错误：undefined symbol: _ZN18Sphere_intersecterIN4CGAL18Spherical_kernel_3INS0_9CartesianINS0_4GmpqEEENS0_32Algebraic_kernel_for_spheres_2_3IS3_EEEEEC1ERKS8_ (./thickness_diag.so)

其中，当翻译通过c++filt http://linux.die.net/man/1/c++filt，给出：Sphere_intersecter<...> >::Sphere_intersecter(Sphere_intersecter<...> const&)

未实现的复制构造函数（不可复制的类）...

解决方案是删除添加boost::noncopyable参数为boost::python::class_:

#include <boost/python.hpp>
#include <CGAL/Exact_spherical_kernel_3.h>
#include "Sphere_intersecter.h"

typedef CGAL::Exact_spherical_kernel_3 SK;
template class Sphere_intersecter<SK>;
typedef Sphere_intersecter<SK> SI;

BOOST_PYTHON_MODULE(thickness_diag)
{
    using namespace boost::python;
    class_<SI, boost::noncopyable>("SphereIntersecter")
        .def("add_sphere", &SI::add_sphere)
    ;
}