Trouble linking FORTRAN DLL with C++ application (undefined reference)

From: Steve Kramer (dr_steve_kramer_at_hotmail.com)
Date: 01/28/04 

Date: 27 Jan 2004 17:16:06 -0800

I created a FORTRAN DLL with Digital Visual Fortran 6.0 and have been
able to access that DLL successfully from a calling application in
FORTRAN.

I'm now trying to call the same FORTRAN DLL from C++ and am having
trouble with the getting the calling conventions right. I have
reviewed some relevant articles in comp.lang.fortran and in the Intel
developer forum, including these:

http://groups.google.com/groups?selm=68rm8a%249ej%40usenet.pa.dec.com&oe=UTF-8&output=gplain

http://groups.google.com/groups?selm=9prq7m%24kef4q%241%40ID-106075.news.dfncis.de&oe=UTF-8&output=gplain

http://softwareforums.intel.com/ids/board/message?board.id=15&message.id=739

Based on those and other articles, here's how I set things up.

(1) FORTRAN DLL source code:
        
Subroutine FORTRANINIT(int1,int2)
!
!
!DEC$ ATTRIBUTES DLLEXPORT::FORTRANINIT
!DEC$ ATTRIBUTES ALIAS : "_FORTRANINIT@8" :: FORTRANINIT

INTEGER*4 int1, int2

(2) Calling C++ program source code:

extern "C"
  {
      __declspec(dllimport) void __stdcall FORTRANINIT(int* int1,
            int* int2);
  }

  void main()
  {
        int int1, int2;

   <snip>

        FORTRANINIT(&int1, &int1);
  }

(3) Building/compiling:
  
(a) I built FORTRANINIT.dll first (in DVF 6.0) and copied it to the
    C++ application's directory.

(b) I added the FORTRANINIT.lib file to the C++ project in Bloodshed
    Dev-C++ 4.0 (from www.bloodshed.net/devcpp.html) and compiled the
    calling C++ application.

(c) There were no compilation errors, but there was a linker error:

    undefined reference to `_imp__FORTRANINIT@8'

Any ideas as to what I'm missing here? I would like to be able to
call the same FORTRAN DLL from FORTRAN and C++. I have tried
omitting both the FORTRAN ALIAS as well as the __declspec(dllimport)
in C++ without any luck.

Thanks in advance for the help!

 - Steve Kramer

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