在Cython中使用移动方法时的汇编误差

Compilation error when using the move method in Cython

本文关键字:汇编 误差 方法 移动 Cython      更新时间:2023-10-16

我的问题类似于这里问的问题 - 将C 向量通过Cython传递给Numpy而无需自动复制和照顾内存管理,我也会得到分段错误,但在我可以解决它之前我在Cython中的移动方法有一些汇编错误。

这是我拥有的最简单的示例(只是Net提供的矩形示例的扩展

我想做什么我的C 代码返回点数。它也可以返回积分的向量。任何容器都会做

在Cython代码中,我想将返回的点(每次迭代循环的迭代(存储在集合中(例如向量或Deque(中。该集合将是实例变量。

稍后,我想通过集合进行迭代,然后将点的Deque转换为列表列表。我相信我相信我会遇到细分错误。

point.h

#ifndef POINT_H
#define POINT_H
class  Point
{
  private:
  double coordinate1,coordinate2;
  public:
   virtual double  getCoordinate1() const;
   virtual double  getCoordinate2() const ;
   virtual void    setCoordinate1(double coordinate1);
  virtual void    setCoordinate2(double coordinate2);
 };

Rectangle.h

   #include <deque>
   #include "Point.h"
   using std:deque;
   deque<Point> getAllPoints(Point query);

Rectangle.cpp

    include "Rectangle.h"
     deque<Point> Rectangle::getAllPoints(Point query)
     {
      deque<Point> deq;
        for (int i = 0;i < 10000; ++i)
         {
           deq.push_back(query);
         }
      return deq;

NOTE 与链接的问题不同,我没有返回地址,而是返回参考

rect.pxd

 cdef extern from "<utility>" namespace "std" nogil:
   T move[T](T) #
 cdef extern from "Point.h":
   cdef cppclass Point:
   Point() nogil except +
   double getCoordinate1()
   double getCoordinate2()
   void setCoordinate1(double coordinate1) nogil
   void setCoordinate2(double coordinate2) nogil
cdef cppclass SphericalPoint(Point):
   SphericalPoint() nogil except +
   double getCoordinate1()
   double getCoordinate2()
   void setCoordinate1(double lat) nogil
   void setCoordinate2(double lon) nogil
cdef extern from "Rectangle.h" namespace "shapes":
   cdef cppclass Rectangle:
     Rectangle(int, int, int, int) except + nogil
     deque[Point] getArea(Point p) nogil

最后

rect.pyx

 cdef class PyRectangle:
   cdef Rectangle *rect    
   cdef deque[Point] colOfPoints
   def __cinit__(self, int x0, int y0, int x1, int y1):
    self.rect = new Rectangle(x0, y0, x1, y1)
    self.colOfPoints = deque[Point]()
 def performCalc(self,maxDistance,chunk):
    cdef deque[Point] area
    cdef double[:,:] gPoints
    gPoints = memoryview(chunk)
    for i in range(0,len(gPoints)):
        with nogil:
            area =  self.getArea(gPoints[i])
            self.colOfPoints = move(area)
cdef deque[Point] getArea(self,double[:] p) nogil:
    cdef deque[Point] area
    area = self.rect.getArea(point)
    return area

我相信我正在设置c 17在setup.pyx

setup.py

  os.environ['CFLAGS'] = '-O3 -Wall -std=c++17'
  ext_modules = [Extension("rect",
                     ["rect.pyx","Rectangle.cpp"],
                     include_dirs=['/usr/local/include'],
                     extra_link_args=["-std=c++17"],
                     language='c++',
                 )]

extensions = cythonize(ext_modules,language_level =" 3"(

我得到这些汇编错误

 rect.cpp: In function ‘PyObject*   __pyx_pf_4rect_11PyRectangle_6performCalc(__pyx_obj_4rect_PyRectangle*, PyObject*, PyObject*)’:
 rect.cpp:3781:81: error: no matching function for call to ‘move<std::deque<Point, std::allocator<Point> > >(std::deque<Point>&)’
       __pyx_v_self->colOfPoints = std::move<std::deque<Point> >(__pyx_v_area);
                                                                             ^
     In file included from /usr/include/c++/7 /bits/nested_exception.h:40:0,
             from /usr/include/c++/7/exception:143,
             from /usr/include/c++/7/ios:39,
             from rect.cpp:632:
   /usr/include/c++/7/bits/move.h:98:5: note: candidate: template<class _Tp> constexpr typename std::remove_reference< <template-parameter-1-1> >::type&& std::move(_Tp&&)
 move(_Tp&& __t) noexcept
 ^~~~
 /usr/include/c++/7/bits/move.h:98:5: note:   template argument deduction/substitution failed:
  rect.cpp:3781:81: note:   cannot convert ‘__pyx_v_area’ (type ‘std::deque<Point>’) to type ‘std::deque<Point>&&’
       __pyx_v_self->colOfPoints = std::move<std::deque<Point> >(__pyx_v_area);
                                                                             ^
 In file included from /usr/include/c++/7/bits/char_traits.h:39:0,
             from /usr/include/c++/7/ios:40,
             from rect.cpp:632:
 /usr/include/c++/7/bits/stl_algobase.h:479:5: note: candidate: template<class _II, class _OI> _OI std::move(_II, _II, _OI)
 move(_II __first, _II __last, _OI __result)
 ^~~~
 /usr/include/c++/7/bits/stl_algobase.h:479:5: note:   template argument deduction/substitution failed:
    rect.cpp:3781:81: note:   candidate expects 3 arguments, 1 provided
       __pyx_v_self->colOfPoints = std::move<std::deque<Point> >(__pyx_v_area);
                                                                                    ^
   In file included from /usr/include/c++/7/deque:66:0,
             from rect.cpp:636:
   /usr/include/c++/7/bits/deque.tcc:1048:5: note: candidate: template<class _Tp> std::_Deque_iterator<_Tp, _Tp&, _Tp*> std::move(std::_Deque_iterator<_Tp, const _Tp&, const _Tp*>, std::_Deque_iterator<_Tp, const _Tp&, const _Tp*>, std::_Deque_iterator<_Tp, _Tp&, _Tp*>)
 move(_Deque_iterator<_Tp, const _Tp&, const _Tp*> __first,
 ^~~~
   /usr/include/c++/7/bits/deque.tcc:1048:5: note:   template argument deduction/substitution failed:
  rect.cpp:3781:81: note:   candidate expects 3 arguments, 1 provided
       __pyx_v_self->colOfPoints = std::move<std::deque<Point> >(__pyx_v_area);
                                                                             ^
   In file included from /usr/include/c++/7/deque:64:0,
             from rect.cpp:636:
  /usr/include/c++/7/bits/stl_deque.h:424:5: note: candidate: template<class _Tp> std::_Deque_iterator<_Tp, _Tp&, _Tp*> std::move(std::_Deque_iterator<_Tp, _Tp&, _Tp*>, std::_Deque_iterator<_Tp, _Tp&, _Tp*>, std::_Deque_iterator<_Tp, _Tp&, _Tp*>)
 move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
 ^~~~
  /usr/include/c++/7/bits/stl_deque.h:424:5: note:   template argument deduction/substitution failed:
  rect.cpp:3781:81: note:   candidate expects 3 arguments, 1 provided
       __pyx_v_self->colOfPoints = std::move<std::deque<Point> >(__pyx_v_area);

以下是我用来重现您的问题的稍微简化版本。我只是将其包括在内,以说明如何进一步剪切您的示例 - 请注意,我不需要使用C 文件 - 我可以通过将代码直接包含在PYX文件中。

#distutils: language = c++
from libcpp.deque cimport deque
cdef extern from *:
    """
    #include <deque>
    using std::deque;
    class Point{};
    deque<Point> getAllPoints() {
        deque<Point> deq;
        for (int i=0; i<10000; ++i) {
            deq.push_back(Point{});
        }
        return deq;
    }
    """
    cdef cppclass Point:
        pass
    deque[Point] getAllPoints()
cdef extern from "<utility>" namespace "std" nogil:
    T move[T](T)
cdef class PyRectange:
    cdef deque[Point] colOfPoints
    def something(self):
        cdef deque[Point] area = self.getArea()
        self.colOfPoints = move(area)
    cdef deque[Point] getArea(self):
        return getAllPoints()

基本问题是,当Cython生成模板的C 代码时,它会写入std::move<deque<Point>>(area)而不是std::move(area)并让C 推断模板类型。由于原因,我不完全理解这似乎在很多时候都会生成错误的代码。

我有两个半解决方案:

  1. 不要告诉Cython move是模板功能。相反,只需告诉它您想要的过载:

    cdef extern from "<utility>" namespace "std" nogil:
        deque[Point] move(deque[Point])
    

    我认为这是最简单的,也许是我的方法。

  2. 如果避免创建临时area,则C 代码确实可以与模板一起使用:

    self.colOfPoints = move(self.getArea())
    

    我怀疑在这种情况下,您甚至不需要move -C 可能会自动使用移动分配操作员。

  3. 这个答案声称提出了一个小包装器,可以帮助Cython致电正确的move(在回答的问题上,它也有些错过了实际问题...(。我没有自己测试过,但是如果您想要模板的举动,那可能值得一试。