在Ada95/构造函数和受控类型中使用C++类

在Ada95/构造函数和受控类型中使用C++类

我希望能够在我的Ada代码中使用C++类。我的目标是保持Ada代码可移植到Ada95规范。我不想使用GNAT或Ada05特定方法。

我使用C中带有包装器函数的pragma Import（C）来实现接口。但我很难弄清楚如何获得我的C++Ctors/Dtors自动呼叫。我的第一个想法是使用Ada控制类型Initialize将调用Ctor，Finalize将调用Dtor。这一切都很好，直到我有了一个需要我传递参数的Ctor。

Foo.h

class Foo
{
public:
    Foo();
    Foo(long x, long y, long z);
    Foo(const Foo& that);
    ~Foo();
    Foo& operator=(const Foo& that);
    long getX() const;
    long getY() const;
    long getZ() const;
    void setX(long x);
    void setY(long y);
    void setZ(long z);
private:
    long mX;
    long mY;
    long mZ;    
};

Foo_Exports.cpp

#include "foo.h"
#include <new>
extern "C"
{
    void extFoo_New    (Foo* foo) { new (foo) Foo(); }  
    void extFoo_NewXYZ (Foo* foo, long x, long y, long z)   { new (foo) Foo(x,y,z); }
    void extFoo_Delete (Foo* foo) { foo->~Foo(); }  
    long extFoo_getX(const Foo& foo) { return foo.getX(); }
    long extFoo_getY(const Foo& foo) { return foo.getY(); }
    long extFoo_getZ(const Foo& foo) { return foo.getZ(); }
    void extFoo_setX(const Foo& foo, long x) { foo.setX(x) };
    void extFoo_setY(const Foo& foo, long y) { foo.setY(y) };
    void extFoo_setZ(const Foo& foo, long z) { foo.setZ(z) };
}

cpp.foo.ads

with Ada.Finalization;
with Interfaces.C;
use Interfaces.C;
package Cpp.Foo is
    type Obj_t is new Ada.Finalization.Controlled_Type with private;
    procedure Initialize (This : in out Obj_T);
    procedure Adjust     (This : in out Obj_T);
    procedure Finalize   (This : in out Obj_T);
    function Get_X (This : access Obj_T) return Long;
    function Get_Y (This : access Obj_T) return Long;
    function Get_Z (This : access Obj_T) return Long;
    procedure Set_X(This : access Obj_T; 
                    X    : in     Long );
    procedure Set_Y(This : access Obj_T; 
                    Y    : in     Long );
    procedure Set_Z(This : access Obj_T; 
                    Z    : in     Long );
private
    type Obj_t is new Ada.Finalization.Controlled_Type with null record;
    for Obj_T'Size use 192;
    for Obj_T'Alignment use 8;
    pragma Import (C, Get_X, "extFoo_getX");
    pragma Import (C, Get_Y, "extFoo_getY");
    pragma Import (C, Get_Z, "extFoo_getZ");
    pragma Import (C, Set_X, "extFoo_setX");
    pragma Import (C, Set_Y, "extFoo_setY");
    pragma Import (C, Set_Z, "extFoo_setZ");
end Cpp.Foo;

cpp.foo.adb

with System;
package body Cpp.Foo is
    procedure Initialize (This : in out Obj_T) is
        procedure ExtFoo_New(Addr : in System.Address);
        pragma Import (C, ExtFoo_New "extFoo_New");
        procedure ExtFoo_NewXYZ(Addr  : in System.Address,
                                X     : in Long;
                                Y     : in Long;
                                Z     : in Long);
        pragma Import (C, ExtFoo_NewXYZ "extFoo_NewXYZ");
    begin
        null; -- **WHAT DO I DO HERE?!**
    end Initialize;
    procedure Adjust     (This : in out Obj_T) is
    begin
        null; -- TBD copy ctor
    end Adjust;
    procedure Finalize   (This : in out Obj_T) is
        procedure ExtFoo_Delete(Addr : in System.Address);
        pragma Import (C, ExtFoo_Delete, extFoo_Delete);
    begin
        ExtFoo_Delete(This'address);
    end Finalize;

end Cpp.Foo;