PRB: LNK4022 & LNK4006 Warnings When Build PowerStation 32 DLL

• Microsoft FORTRAN PowerStation 32 for Windows NT, versions 1.0 and 4.0

SYMPTOMS

The following errors are generated when building a DLL using a module definition (.DEF) file that does not use the fully decorated name of a function named testing:

   warning LNK4022: cannot find unique match for symbol "TESTING"
   warning LNK4006: _TESTING already defined in test.obj; second
      definition ignored
   warning LNK4006: _TESTING@4 already defined in test.obj; second
      definition ignored
   LINK : error LNK1141: failure during build of exports file

RESOLUTION

Use the fully decorated name in the EXPORTS section of the DEF file or the LINK command line.

MORE INFORMATION

There may be times when it is desirable not to modify the Fortran source code to add the DLLEXPORT attribute to a function. For example, you might want to maintain a common code base for several computer platforms. In this case, the exports must be identified in the EXPORTS section of a .DEF file or the LINK command line. In either case, if the name specified is not the fully decorated name, the errors described above will be generated by the linker.

Steps to Reproduce Problem

1. Use the sample code listed at the end of this article and this definitions file:

   library test EXPORTS TESTING

2. Use the following LINK command to generate the error messages:

   link test.obj /dll /def:test.def msfrt.lib msvcrt.lib

Example Resolution

To successfully link and produce a DLL, include the fully decorated name in the .DEF file:

   library test
   EXPORTS _TESTING@4

   link test.obj /dll /export:_TESTING@4 msfrt.lib msvcrt.lib

Sample Code

C Compile options needed: none

        subroutine testing(i)
        integer i
        i = i*2
        end