KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q59489: L2022, L2029 on PM Functions Not Prototyped As EXPENTRY

Article: Q59489
Product(s): See article
Version(s): 5.10
Operating System(s): OS/2
Keyword(s): ENDUSER | o_os2sdk | mspl13_c
Last Modified: 15-MAR-1990

Problem:

I receive the following error messages when I link my PM (Presentation
Manager) program:

   LINK : error L2022: ClientWndProc (alias ClientWndProc) :
          export undefined

   LINK : error L2029 : 'ClientWndProc' : unresolved external

Response:

Most frequently, this problem is caused by having an /NOI linker
option, which forces the linker to distinguish between uppercase and
lowercase. For more information, search the knowledge base using the
following query:

   L2022 and L2029 and /noi

These linker error messages may also occur if you forget to prototype
your functions with the EXPENTRY keyword. The EXPENTRY keyword is
defined in OS2DEF.H as follows:

   #define EXPENTRY far pascal

The "pascal" keyword instructs the compiler to use left-to-right
calling sequences for the function it modifies. The keyword also
causes the conversion of the function's name to uppercase letters.

Not using the EXPENTRY keyword means that your function names are not
converted to uppercase, so even though you declare a .DEF file, which
includes the following line

   EXPORTS        ClientWndProc

the linker cannot resolve definitions for the function because it does
not see ClientWndProc and CLIENTWNDPROC as being equal.

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.