dll problem

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.

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

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.

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

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.

may i post the zip file of my project?

Thanks

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

subroutine sub1
print*,'Hello from sub1'
end

File main.f90

program main
call sub1
end

Building from a command line

ftn95 lib1 /link lib1.dll
ftn95 main /link /ref lib1.dll

Another way to build from a command line

ftn95 lib1
slink lib1.obj -dll -exportall
ftn95 main
slink main.obj lib1.dll

In both cases the executable is main.exe

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

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.