Re: VC++ .NET 2005 prepending underscore to external functions references

From:

"William DePalo [MVP VC++]" <willd.no.spam@mvps.org>

Newsgroups:

microsoft.public.vc.ide_general

Date:

Wed, 23 Aug 2006 00:40:15 -0400

Message-ID:

<Obvk74mxGHA.476@TK2MSFTNGP06.phx.gbl>

"Jett Gamboa" <jett@discussions.microsoft.com> wrote in message
news:44EBB347.20501@discussions.microsoft.com...

Here's are the exported functions in the the DLL dump:

    ordinal hint RVA name

          1 0 00001FF0 Clear_Device_Prn
          2 1 00002420 Get_Prn_Ver
          3 2 000012F0 Get_Ticket
          4 3 00001F70 Init_Device_Prn
...
And here's a snippet from the header file of the said DLL:

#if !defined(__YL31HC_H_)
#define __YL31HC_H_

#if !defined(_MSC_VER)
#define __stdcall
#endif //#if !defined(_MSC_VER)

//device control
int __stdcall Init_Device_Prn(void);
void __stdcall Clear_Device_Prn(void);

//printer
int __stdcall Prn_String(unsigned char *Prn_Str);
int __stdcall Prn_Set_Abs_XY(unsigned char Px, unsigned char Py);
int __stdcall Prn_Setfont(unsigned char Fonttype, unsigned char Wide,
unsigned char High);
//return 1:success
int __stdcall Prn_Set_Dev_Temp(unsigned char Temp);
int __stdcall Prn_BlockCode(unsigned char *Block_Code, int Bit_Length);
int __stdcall Prn_Start(void);
char __stdcall Prn_Detect(void);

//reader
int __stdcall Get_Ticket(int *Line, unsigned char *Ticket_Info, int
*Code_Length, int *Ticket_Type);

#endif //#if !defined(__YL31HC_H_)

I get the following errors:

error LNK2019: unresolved external symbol _Clear_Device_Prn@0 referenced
in function _main yl3100rp2tester.obj

Did you add the import library to your executable's project? If so, try
embellishing the declarations in the header so that the compiler knows to
import them

__declspec(dllimport) int _stdcall Get_Ticket(int *Line, ...);

The brute force fix would be to rebuild the DLL with a module definition
file in which you tag every export with two names

    LIBRARY yourDLLName

        EXPORTS

            .
            .
            .
             _Clear_Device_Prn@0 = Clear_Device_Prn
            .
            .
            .

Regards,
Will