WinRT WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) symbols creating problems in using #import code

Question

I am not able to use a COM dll which i #import-ed because it doesn't compile. For some reason, part of the stuff in the tlh file resulting from the import uses stuff under WINAPI_PARTITION_DESKTOP, which prevents it from compiling. For example, _com_error uses IErrorInfo below, which is deffed out.

 #ifndef __IErrorInfo_INTERFACE_DEFINED__
#define __IErrorInfo_INTERFACE_DEFINED__

/* interface IErrorInfo */
/* [unique][uuid][object] */

typedef /* [unique] */  __RPC_unique_pointer IErrorInfo *LPERRORINFO;

EXTERN_C const IID IID_IErrorInfo;

#if defined(__cplusplus) && !defined(CINTERFACE)
   
    MIDL_INTERFACE("1CF2B120-547D-101B-8E65-08002B2BD119")
    IErrorInfo : public IUnknown
    {
    public:
        virtual HRESULT STDMETHODCALLTYPE GetGUID(
            /* [out] */ __RPC__out GUID *pGUID) = 0;
       
        virtual HRESULT STDMETHODCALLTYPE GetSource(
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrSource) = 0;
       
        virtual HRESULT STDMETHODCALLTYPE GetDescription(
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrDescription) = 0;
       
        virtual HRESULT STDMETHODCALLTYPE GetHelpFile(
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrHelpFile) = 0;
       
        virtual HRESULT STDMETHODCALLTYPE GetHelpContext(
            /* [out] */ __RPC__out DWORD *pdwHelpContext) = 0;
       
    };
   
   
#else  /* C style interface */

    typedef struct IErrorInfoVtbl
    {
        BEGIN_INTERFACE
       
        HRESULT ( STDMETHODCALLTYPE *QueryInterface )(
            __RPC__in IErrorInfo * This,
            /* [in] */ __RPC__in REFIID riid,
            /* [annotation][iid_is][out] */
            __RPC__deref_out _Result_nullonfailure_  void **ppvObject);
       
        ULONG ( STDMETHODCALLTYPE *AddRef )(
            __RPC__in IErrorInfo * This);
       
        ULONG ( STDMETHODCALLTYPE *Release )(
            __RPC__in IErrorInfo * This);
       
        HRESULT ( STDMETHODCALLTYPE *GetGUID )(
            __RPC__in IErrorInfo * This,
            /* [out] */ __RPC__out GUID *pGUID);
       
        HRESULT ( STDMETHODCALLTYPE *GetSource )(
            __RPC__in IErrorInfo * This,
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrSource);
       
        HRESULT ( STDMETHODCALLTYPE *GetDescription )(
            __RPC__in IErrorInfo * This,
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrDescription);
       
        HRESULT ( STDMETHODCALLTYPE *GetHelpFile )(
            __RPC__in IErrorInfo * This,
            /* [out] */ __RPC__deref_out_opt BSTR *pBstrHelpFile);
       
        HRESULT ( STDMETHODCALLTYPE *GetHelpContext )(
            __RPC__in IErrorInfo * This,
            /* [out] */ __RPC__out DWORD *pdwHelpContext);
       
        END_INTERFACE
    } IErrorInfoVtbl;

    interface IErrorInfo
    {
        CONST_VTBL struct IErrorInfoVtbl *lpVtbl;
    };

 

#ifdef COBJMACROS

#define IErrorInfo_QueryInterface(This,riid,ppvObject) \
    ( (This)->lpVtbl -> QueryInterface(This,riid,ppvObject) )

#define IErrorInfo_AddRef(This) \
    ( (This)->lpVtbl -> AddRef(This) )

#define IErrorInfo_Release(This) \
    ( (This)->lpVtbl -> Release(This) )

#define IErrorInfo_GetGUID(This,pGUID) \
    ( (This)->lpVtbl -> GetGUID(This,pGUID) )

#define IErrorInfo_GetSource(This,pBstrSource) \
    ( (This)->lpVtbl -> GetSource(This,pBstrSource) )

#define IErrorInfo_GetDescription(This,pBstrDescription) \
    ( (This)->lpVtbl -> GetDescription(This,pBstrDescription) )

#define IErrorInfo_GetHelpFile(This,pBstrHelpFile) \
    ( (This)->lpVtbl -> GetHelpFile(This,pBstrHelpFile) )

#define IErrorInfo_GetHelpContext(This,pdwHelpContext) \
    ( (This)->lpVtbl -> GetHelpContext(This,pdwHelpContext) )

#endif /* COBJMACROS */

#endif  /* C style interface */

 

#endif  /* __IErrorInfo_INTERFACE_DEFINED__ */

 

Answer 1

Just to clarify, the error/grayed out sections occur in #include <comdef.h> which needs to be included before the #import "foo.dll" so that the interfaces used/spat out as implemented by the import can see it.

Answer 2

It gets worse. After i hacked it to redefine this IErrorInfo section elsewhere, i run into a fresh set of common defines which are defined in windows.h/winbase.h under "WINAPI_PARTITION_DESKTOP" while the metro app uses WINAPI_PARTITION_APP.

 

Error 1 error C3861: 'LocalFree': identifier not found c:\program files (x86)\microsoft visual studio 11.0\vc\include\comdef.h 154 1 qbsdkWinRTComponent
Error 2 error C3861: 'lstrlen': identifier not found c:\program files (x86)\microsoft visual studio 11.0\vc\include\comdef.h 244 1 qbsdkWinRTComponent
Error 3 error C3861: 'LocalAlloc': identifier not found c:\program files (x86)\microsoft visual studio 11.0\vc\include\comdef.h 253 1 qbsdkWinRTComponent
 4 IntelliSense: identifier "LocalFree" is undefined c:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\comdef.h 154 9 qbsdkWinRTComponent
 5 IntelliSense: identifier "lstrlen" is undefined c:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\comdef.h 244 24 qbsdkWinRTComponent
 6 IntelliSense: identifier "LocalAlloc" is undefined c:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\comdef.h 253 32 qbsdkWinRTComponent

Answer 3

The incompatibliity between comdef.h and building with /ZW (C++/CX) is a known bug. It should be fixed in the future. Right now, you're not going to be able to use #import in C++/CX.

Answer 4

I have the same problem : is it fixed in VS2015, and if not, is make use of #import in C++/CX planned ?

thanks in advance