Visual Studio 2008 release build not decorating DLL exports

问题

I'm building a C++ DLL in Visual Studio 2008 to be used by a C application written in Borland C++ Builder 6.

My debug DLL build exports methods decorated with an underscore. However in my release DLL build the methods are not decorated causing linker errors in C++ Builder. (See below for output for dumpbin.exe for both build types)

I've checked the compiler options for both debug and release configuration and cannot see anything that might be causing this problem.

I've managed it get around the problem. The Borland tool implib, which converts Visual Studio .lib files to a C++ Builder .lib files, can add an underscore. But I would like to understand why the exports are not being decorated.

Header file methods.h

#ifndef METHODS_H
#define METHODS_H

#ifdef ENCRYPTION_EXPORTS
#define DLLEXPORT __declspec(dllexport)
#else
#define DLLEXPORT __declspec(dllimport)
#endif

#ifdef __cplusplus
extern "C"
{
#endif

DLLEXPORT BOOL EncryptString(char *szPlain, char *szEncrypted);
DLLEXPORT BOOL DecryptString(char *szEncrypted, char *szPlain);
DLLEXPORT BOOL EncryptInitialise(void);
DLLEXPORT void EncryptExit(void);

#ifdef __cplusplus
}
#endif

#endif

Dumpbin.exe output for debug build

dumpbin /EXPORTS encryption.dll

Microsoft (R) COFF/PE Dumper Version 9.00.30729.01
Copyright (C) Microsoft Corporation.  All rights reserved.

Dump of file encryption.dll

File Type: DLL

  Section contains the following exports for encryption.dll

    00000000 characteristics
    50B8B22E time date stamp Fri Nov 30 13:18:38 2012
        0.00 version
           1 ordinal base
           4 number of functions
           4 number of names

    ordinal hint RVA      name

          1    0 000308F7 DecryptString = @ILT+2290(_DecryptString)
          2    1 00031635 EncryptExit = @ILT+5680(_EncryptExit)
          3    2 000303CF EncryptInitialise = @ILT+970(_EncryptInitialise)
          4    3 0003003C EncryptString = @ILT+55(_EncryptString)

  Summary

        5000 .data
        1000 .idata
       13000 .rdata
        5000 .reloc
        1000 .rsrc
       64000 .text
       2F000 .textbss

Dumpbin.exe output for release build

dumpbin /EXPORTS encryption.dll

Microsoft (R) COFF/PE Dumper Version 9.00.30729.01
Copyright (C) Microsoft Corporation.  All rights reserved.

Dump of file encryption.dll

File Type: DLL

  Section contains the following exports for encryption.dll

    00000000 characteristics
    50B8BE14 time date stamp Fri Nov 30 14:09:24 2012
        0.00 version
           1 ordinal base
           4 number of functions
           4 number of names

    ordinal hint RVA      name

          1    0 00001A10 DecryptString
          2    1 000012C0 EncryptExit
          3    2 00001370 EncryptInitialise
          4    3 00001820 EncryptString

  Summary

        4000 .data
        4000 .rdata
        2000 .reloc
        1000 .rsrc
        F000 .text

回答1:

here is an article about calling conventions and name decoration. the name decoration may be overruled by a *.def file in your project.

来源：https://stackoverflow.com/questions/13648951/visual-studio-2008-release-build-not-decorating-dll-exports

标签

c++

visual-studio-2008

dll

dllexport