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cecio · Joined: 02 Sep 2007 Posts: 11

Hi,
we would like to create a project containing a simple fortran exe and a simple fortran dll.

when we try to execute we have "Error 29, Call to missing routine : _SUBSIMPLE@0 at 0x00401027"

the code is:
(exe)

F_stdcall SubSimple
call SubSimple()
stop
end

( dll )
SUBROUTINE SubSimple
PRINT *,"Simple subroutine called"
END SUBROUTINE

We also try with exportall switch, without success.

How can we solve?
Have you some example of fortran exe calling fortran dll?
thanks.

Keith Waters · Posted: Sat Jan 12, 2008 1:13 am Post subject:

Wild guess – try all lowercase subroutine name (or all upper).

PaulLaidler · Posted: Sat Jan 12, 2008 8:53 am Post subject:

If you are compiling the DLL using FTN95 then you do not need F_STDCALL. Alternatively you must use F_STDCALL in both your DLL and executable.

FTN95 code is not case-sensitive. Only uppercase names are passed to the linker. This only becomes an issue if you are accessing a Fortran DLL from non-Fortran code.

cecio · Joined: 02 Sep 2007 Posts: 11

I try with lovercase and uppercase, with and without F_STANDARD.....

No way....

may my problem be in some project parameters?

have you some solution example (like "visualcinteroperability" with fortran instead of C) ?

thanks

PaulLaidler · Posted: Tue Jan 15, 2008 8:18 am Post subject:

Your sample looks OK if you take out the F_STDCALL line.

Your DLL must be in the same folder as your exe or alternatively it could be in a folder that is included in the PATH environment variable.

cecio · Joined: 02 Sep 2007 Posts: 11

may i post the zip file of my project?

Thanks

PaulLaidler · Posted: Wed Jan 16, 2008 8:44 am Post subject:

We would need to make a charge for this service.
You can send an email to Silverfrost to ask for details.

Here is a simple example that may help. Remember to keep the results in one folder.

File lib1.f90

cecio · Joined: 02 Sep 2007 Posts: 11

Thanks PaulLaidler

with your instructions and command line it works.
But i need to understand some things....

why you link main.obj whith lib1.dll?

I think my problem is here.

Is there a way to indicate in the source ( and not at link time) where is my dll?

( in vb6 i add line like:
Declare Function iajfltdll Lib "pcroutdll.dll" (i4 As Long, dd As Single) As Integer )

Thanks

PaulLaidler · Posted: Thu Jan 17, 2008 6:39 pm Post subject:

The linker needs to know where the DLL is both for its own use and to embed this information in the executable.

There is a LIBRARY directive that you can write into the code but this only works when you use /LINK or /LGO on the FTN95 command line.

The recommended route is to create a project in either Plato3 or Visual Studio and then all of this information goes into the project data.