FIX: LNK1152 & LNK1141 When Linking OLE Control to Mapi32.lib

The information in this article applies to:

• The MAPI32.LIB included with: Microsoft Visual C++, 32-bit Edition, version 4.0

SYMPTOMS

Attempting to link an OLE Control project with Mapi32.lib results in the following warnings and errors:

warning LNK4022: cannot find unique match for symbol "DllCanUnloadNow" warning LNK4002: _DllCanUnloadNow defined in C:\MSDEV\LIB\MAPI32.LIB warning LNK4002: _DllCanUnloadNow@0 defined in

                 C:\MSDEV\MFC\lib\mfcs40d.lib

                 C:\MSDEV\LIB\oleaut32.lib

                 "DllGetClassObject"

                 C:\MSDEV\MFC\lib\mfcs40d.lib

                 C:\MSDEV\LIB\oleaut32.lib

CAUSE

The import library for the Mapi32.dll (Mapi32.lib) incorrectly exports the DllCanUnloadNow and DllGetClassObject functions. These functions should be exported privately and not included in the import library.

RESOLUTION

To work around this problem, build the Mapi32.lib import library from scratch by using the Lib.exe utility included with Visual C++ 4.0.

Copy the sample code listed below into a text file, and save it as Mapi32.def. From the command prompt, enter the following command line to execute the Lib.exe utility and build a new Mapi32.lib import library:

   LIB /DEF:MAPI32.DEF

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++ 4.1.

MORE INFORMATION

For additional information on how to build import libraries without access to source files, please refer to the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q131313
   TITLE     : How to Create 32-bit Import Libraries Without .OBJs
               or Source

Sample Code

; Mapi32.def : Used DUMPBIN /EXPORTS to determine the functions and ; ordinal values listed in the EXPORTS section below. Note ; DllCanUnloadNow, DllGetClassObject, and WEP are NOT listed below.

LIBRARY      "MAPI32.DLL"

      BMAPIAddress      @35
      BMAPIDetails      @37
      BMAPIFindNext     @34
      BMAPIGetAddress   @36
      BMAPIGetReadMail  @33
      BMAPIReadMail     @32
      BMAPIResolveName  @38
      BMAPISaveMail     @31
      BMAPISendMail     @30
      MAPIAddress       @19
      MAPIDeleteMail    @17
      MAPIDetails       @20
      MAPIFindNext      @16
      MAPIFreeBuffer    @18
      MAPILogoff        @12
      MAPILogon         @11
      MAPIReadMail      @15
      MAPIResolveName   @21
      MAPISaveMail      @14
      MAPISendDocuments @10
      MAPISendMail      @13