Question

我对Cython并不陌生，对c ++也不太了解，并且正在尝试获取包装其参数通过引用传递的c ++函数的简单示例。这是我的test.h

#ifndef TEST
#define TEST

int add(int& a, int& b);

#endif

我的test.cpp：

#include "test.h"

int add(int& a, int& b)
{
    return a + b;
}

我的test.pyx：

#cython: language_level=3

cdef extern from "test.h":
    int add(int&, int&)

cpdef add_em(a, b):
    print(add(a, b))

还有我的setup.py

try:
    from setuptools import setup
    from setuptools import Extension
    from Cython.Distutils import build_ext
except ImportError:
    from distutils.core import setup
    from distutils.extension import Extension

from Cython.Build import cythonize

ext_modules = [Extension(
    "test",
    sources=["test.pyx"],
    language="c++",              # this causes Cython to create C++ source
    )]

setup(
    name='test',
    cmdclass={'build_ext': build_ext},
    ext_modules=ext_modules
)

然后我用python setup.py build_ext --inplace进行编译，该编译似乎没有问题

running build_ext
cythoning test.pyx to test.cpp
building 'test' extension
clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/thestrangequark/Documents/temp/cython/venv/include -I/Users/thestrangequark/.pyenv/versions/3.6.2/Python.framework/Versions/3.6/include/python3.6m -c test.cpp -o build/temp.macosx-10.13-x86_64-3.6/test.o
clang++ -bundle -undefined dynamic_lookup -L/usr/local/opt/readline/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/openssl/lib -L/Users/thestrangequark/.pyenv/versions/3.6.2/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/openssl/lib -L/Users/thestrangequark/.pyenv/versions/3.6.2/lib build/temp.macosx-10.13-x86_64-3.6/test.o -o /Users/thestrangequark/Documents/temp/cython/test.cpython-36m-darwin.so

但是为什么我尝试从python import test收到错误消息

Python 3.6.2 (default, Feb 11 2019, 09:37:08)
[GCC 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.10.44.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import test
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: dlopen(/Users/thestrangequark/Documents/temp/cython/test.cpython-36m-darwin.so, 2): Symbol not found: __Z3addii
  Referenced from: /Users/thestrangequark/Documents/temp/cython/test.cpython-36m-darwin.so
  Expected in: flat namespace
 in /Users/thestrangequark/Documents/temp/cython/test.cpython-36m-darwin.so

我对此错误和找不到什么符号感到困惑。我在这里做什么错了？

在Cython中包装c ++函数

0 个答案: