2403d,d的com哪里错了

原文

感谢任意见解.细节:

>dmd --version
DMD64 D Compiler v2.107.0

参考:
ComObject类
IUnknown接口

我只使用了ComObject类和隐式继承了IUnknown接口,用用ImportC编译并包含以下内容的comheaders.c编写了一些COM测试代码.

#define WINVER 0x0A00
#define _WIN32_WINNT 0x0A00
#define _WIN32_DCOM
#include <wtypes.h>
#include <oleauto.h>
#include <oaidl.h>

用来编译的main.d文件如下.

import std.stdio;
import comheaders;
static import com = core.sys.windows.com;
pragma(lib, "onecore"); //修复两个不相关符号的链接
void main() {auto COMobject = new com.ComObject();//auto COMobject = new ComObject();IUnknown* ip = cast(IUnknown*)COMobject;writeln(COMobject.count);writeln("       ip 虚表: ", ip.lpVtbl);auto 虚表 = COMobject.__vptr;writeln("COMobject 虚表: ", 虚表);writeln("ip &AddRef: ", &ip.lpVtbl.AddRef);writeln("ip offset: ", cast(void*)&ip.lpVtbl.AddRef - cast(void*)ip.lpVtbl);auto ipaddref = cast(void*)ip.lpVtbl.AddRef;writeln("       ip AddRef: ", ipaddref);auto addref = cast(void*)(&COMobject.AddRef).funcptr;writeln("COMobject AddRef: ", addref);writeln("COMobject AddRef : ip AddRef offset: ", addref - ipaddref);COMobject.AddRef();writeln(COMobject.count);ip.lpVtbl.AddRef(ip);writeln(COMobject.count);
}

在此,我从静态导入的core.sys.windows.com创建了一个ComObject,但避免使用D窗口库中的其他内容.该对象包含一个应调用AddRef递增的引用计数.输出如下.

0ip 虚表: 7FF756091A30
COMobject 虚表: 7FF756091A30
ip &AddRef: 7FF756091A38
ip offset: 8ip AddRef: 7FF756027970
COMobject AddRef: 7FF756022EC0
COMobject AddRef : ip AddRef offset: -19120
1
1

即,正确偏移的AddRef调用未干活,且与com.ComObject中AddRef的函数指针不同.因此,无法同外部世界代码正常工作.用

dmd main.d comheaders.c vcintrinsics.lib -P/wd5105

编译,vcintrinsics.lib是我构建的解决DMD不知道一系列MSVC内部函数的问题的一个库,即按此处满足链接器的,而-P/wd5105是在ImportC用作C预处理器时,用来抑制MSVC警告.

我在unknwn.d中,复制了不方便命名的IUnknown接口的源码,并从com.d复制了ComObject类的源码,两者都在C:\D\dmd2\src\druntime\src\core\sys\windows\中.

进入main.d的底部并实验.我用上面活动的注释行,新建了个本地ComObject.一项更改解决了该问题:使用extern(C++),其他链接属性不工作.

这是工作代码.我不得不编辑IUnknown接口,但现在是comheaders.c中的一个结构,在QueryInterface中,并编辑到IUnknown*,并把E_NOINTERFACE编辑到com.E_NOINTERFACE.

并用与IUnknown结构不同的名字定义D接口,所以我设置它为_IUnknown_,但除此外,除了不使用extern(Windows)并以extern(C++)为前缀外,源码不变.
这是main.d的其余部分.

import core.atomic;
extern(C++):
interface _IUnknown_ {HRESULT QueryInterface(IID* riid, void** pvObject);ULONG AddRef();ULONG Release();
}
class ComObject : _IUnknown_
{HRESULT QueryInterface(const(IID)* riid, void** ppv){if (*riid == IID_IUnknown){*ppv = cast(void*)cast(IUnknown*)this;AddRef();return S_OK;}else{   *ppv = null;return com.E_NOINTERFACE;}}ULONG AddRef(){return atomicOp!"+="(*cast(shared)&count, 1);}ULONG Release(){LONG lRef = atomicOp!"-="(*cast(shared)&count, 1);if (lRef == 0){//`free`对象,如果删除该对象,则从`Release()`返回时调用的`postinvariant`将失败.让`GC`收获吧.`删 本;`return 0;}return cast(ULONG)lRef;}LONG count = 0;//对象引用计数
}

现在如下输出:

0ip 虚表: 7FF76B9C0360
COMobject 虚表: 7FF76B9C0360
ip &AddRef: 7FF76B9C0368
ip offset: 8ip AddRef: 7FF76B951580
COMobject AddRef: 7FF76B951580
COMobject AddRef : ip AddRef offset: 0
1
2

显示在ComObjects虚表中,查找AddRef会生成与通过COM接口相同的函数指针,且两者都工作.

工作假设:通过导入core.sys.windows.com引入的ComObject和IUnknown都被破坏了,这是Phobos中对COM的所有支持.请确认或拒绝.

你错误地声明了接口变量.试试如下:

auto COMobject = new com.ComObject();
//auto COMobject = new ComObject();
IUnknown ip = COMobject;
writeln(COMobject.count);
writeln("       ip 虚表: ", ip.lpVtbl);
auto 虚表 = COMobject.__vptr;
writeln("COMobject 虚表: ", 虚表);
writeln("ip &AddRef: ", &ip.lpVtbl.AddRef);
writeln("ip offset: ", cast(void*)&ip.lpVtbl.AddRef - cast(void*)ip.lpVtbl);
auto ipaddref = cast(void*)ip.lpVtbl.AddRef;
writeln("       ip AddRef: ", ipaddref);
auto addref = cast(void*)(&COMobject.AddRef).funcptr;
writeln("COMobject AddRef: ", addref);
writeln("COMobject AddRef : ip AddRef offset: ", addref - ipaddref);
COMobject.AddRef();
writeln(COMobject.count);
ip.lpVtbl.AddRef(ip);
writeln(COMobject.count);