Causes of L2023 : Entry WEP : Export Imported

The information in this article applies to:

• Microsoft LINK for MS-DOS, versions 5.3, 5.31.009, 5.5, and 5.6
• Microsoft C/C++ for MS-DOS, version 7.0
• Microsoft Visual C++ for Windows, version 1.0

SYMPTOMS

When building a dynamic-link library (DLL) with Visual C++, the following linker error can occur:

   L2023 : entry WEP : export imported

CAUSE

This error is usually caused by linking with a third-party DLL's import library that publicly exports its WEP (Windows exit procedure) routine.

RESOLUTION

Although removing the lines

   EXPORTS
      WEP @1 RESIDENTNAME

As stated, the most common cause of this error is linking with another DLL's import library that was built to publicly export a WEP function. If you are linking your DLL with other third-party or in-house import libraries, you may want to examine them closely. If some of these import libraries are yours, you can modify the way they are built so that they don't put their WEP routines into the import library.

Either of the following steps will cause a DLL's exported WEP not to be added to its import library:

• Build the import library using the IMPLIB switch /NOWEP. The /NOWEP switch causes IMPLIB not to attempt to put a DLL's WEP function into the import library it is creating. This is the default when building a DLL with Visual C++ 1.0. This is described in IMPLIB.WRI, in the Visual C++ Tech Notes.

  -or-

• In the DLL's .DEF file, specify the WEP as PRIVATE, using the following syntax:

        EXPORTS
           WEP @1 RESIDENTNAME PRIVATE
  
     This will cause the WEP of the DLL to be exported, but will make
     IMPLIB ignore it, so it shouldn't conflict with anything else. This
     is described in the Visual C++ MSCOPTS.HLP file, which can be
     reached from the Visual C++ Professional Edition's Integrated
     Development Environment (IDE) by selecting Help, Build Tools,
     Module-Definition File Statements, EXPORTS, PRIVATE.
  
  

• Attempt to obtain (from the DLL's developers) an import library without a publicly exported WEP.

  -or-

• Use the IMPLIB utility with the /NOWEP switch on the DLL you are linking to, to create a new import library without a WEP in it. If you do this, first make a backup copy of the import library.

  -or-

• Specify the WEP of the DLL you are building as PRIVATE, as described above. This will cause the WEP of THIS DLL to be ignored by IMPLIB, so it shouldn't conflict with anything else. This probably won't work around the L2023 error, however.

   Windows libraries, C run-time libraries, third-party DLLs

NOTE: It is not recommended that you create your own WEP, rather than exporting the default WEP. DLL termination code should be in an _WEP routine, which the default WEP will call. This is described on page 119 and 120 of the Visual C++ 1.0 "Programming Techniques" manual, and on page 27 and 28 of the Visual C++ 1.0 "C/C++ Version 7.0 Update" manual.

If for some reason you must use your own WEP routine, you may want to examine WEP.ASM in the \MSVC\SOURCE\WIN directory. This is the source for the default WEP that is pulled in from the C run-time libraries. In such a WEP, if your application is a C++ application, you need to make sure to call all destructors of global class objects.

If you are creating a Microsoft Foundation Class (MFC) libraries version 2.0 DLL, then you can override the CWinApp::ExitInstance() member function to do your termination processing.