Visual C++ 6.0 Name mangling, even within extern “C” and dllexport, RPC Stubs not generating

Question

Hey guys im working on creating a new function in legacy visual C++ 6.0 dll project, so that a C# dll can call into, however i unable to do so due to name mangling and it seems no matter what I do I can't stop it, (i used dumpbin to view the names) here is the relevant code

this is a really trimmed down verstion of the header file

#ifdef  _V7SSCOMM_CPP_
#define _DECL_V7COMM_DLL    __declspec(dllexport)
#else
#define _DECL_V7COMM_DLL    __declspec(dllimport)
#endif

#ifdef __cplusplus
extern "C" {
#endif
_DECL_V7COMM_DLL    DWORD V7ssGetFileDirInfoUnicode(LPCSTR szSign, V7_FILE_LIST_TYPE eListType, LPCSTR szServer, LPCSTR szLibrary, LPCSTR szExt, DWORD *pdwFileCnt, wchar_t *pbyFileBuf, DWORD *pdwFileBufSize);

#ifdef __cplusplus
}
#endif

#endif

and for the cpp file

_DECL_V7COMM_DLL    DWORD V7ssGetFileDirInfoUnicode(LPCSTR szSign, 
                                                         V7_FILE_LIST_TYPE eListType, 
                                                         LPCSTR szServer, LPCSTR szLibrary, LPCSTR szExt, 
                                                         DWORD *pdwFileCnt, wchar_t *pbyFileBuf, DWORD *pdwFileBufSize)
{
    if (!szSign || !szServer || !szLibrary || !szExt || !pdwFileCnt || !pbyFileBuf || !pdwFileBufSize)
        return (RPC_S_INVALID_ARG);

    error_status_t Error = rpcGetFileDirInfoUnicode(
        /* [in] */ g_hRpcBinding, 
        /* [in, string] */ (unsigned char *)szSign, 
        /* [in] */ (unsigned long)eListType, 
        /* [in, string] */ (unsigned char *)szServer,
        /* [in, string] */ (unsigned char *)szLibrary,
        /* [in, string] */ (unsigned char *)szExt,
        /* [out] */ (unsigned long *)pdwFileCnt, 
        /* [out, size_is(*pdwFileBufSize)] */ (wchar_t *)pbyFileBuf, 
        /* [in, out] */ (unsigned long *)pdwFileBufSize);

    return (Error);
} // end V7ssGetFileDirInfoUnicode()

dumpbin returns the following 1 0 00001401 ?V7ssGetFileDirInfoUnicode@@YAKPBDW4tag_V7_FILE_LIST_TYPE@@000PAKPAG2@Z

not what i wanted ideally it would only be V7ssGetFileDirInfoUnicode

As far as i can tell and from what i have been reading the way i trying to do this means i don't need to define this in the .def file. What is odd, is im following the same extact setup as pre-existing functions that show up correctly.

I would be grateful for any help.Thanks!

Update

the .def file option works as far as not name mangling, that being said the MIDL compiler is not creating the RPC stub, I think these two issues are related.

also here is the MIDL version, taken from the C file iteself

/* this ALWAYS GENERATED file contains the RPC server stubs */


/* File created by MIDL compiler version 5.01.0164 */
/* at Wed Sep 21 08:57:22 2011
 */
/* Compiler settings for V7Rpc.idl:
    Os (OptLev=s), W1, Zp8, env=Win32, ms_ext, c_ext
    error checks: allocation ref bounds_check enum stub_data 
*/
//@@MIDL_FILE_HEADING(  )

Answer 1

If you are certain that you included the header file from the .cpp file, then you might try adding a .def file to your project. There might be other ways, but that has always seemed to be a critical part in reducing the name mangling in the exports. The contents would look something like this.

EXPORTS
   V7ssGetFileDirInfoUnicode