A Fortran DLL project is created like any other project, but you must specify Dynamic-Link Library as the project type.
Add files to your Fortran DLL project. Include the DLL Fortran source that exports procedures or data as a file in your project.
If your DLL exports data, consistently specify the project settings options in the Fortran Data compiler option category for both the DLL and any image that references the DLL's exported data. In the Fortran Data compiler option category, specify the appropriate values for Common Element Alignment (common block data) and Structure Member Alignment (structures in a module). This sets the
/align
option, which specifies whether padding is needed to ensure that exported data items are naturally aligned.
For example, in the case of a common block containing four-byte variables, you might:
Open the appropriate solution and select the project in the Solution View.
From the
Project>Properties
, select the Fortran category.
Select Data.
In the Common Element Alignment box, select 4 Bytes.
If you need to specify linker options, use the Linker category of the Project Property Pages dialog box.
Build your Fortran DLL project.
The IDE automatically selects the correct linker instructions for loading the proper run-time library routines (located in a DLL themselves). Your DLL is created as a multithread-enabled library. An import library (.LIB) is created for use when you link images that reference the DLL.

If you build a DLL from the command line or use a makefile, you must specify the /dll option. For example, if the Fortran DLL source code is in the file
f90arr.f90
, use the following command line:
ifort /dll f90arr.f90
This command creates:
A DLL named
f90arr.dll
.
An import library,
f90arr.lib
, that you must link with applications that call your DLL.
If you also specify
/exe:
file
or
/link /out:
file
, the file name you specify is used for a .DLL rather than an .EXE file (the default file extension becomes
projectname
.DLL instead of
projectname
.EXE)
The
/dll
option selects, as the default, the DLL run-time libraries to support multithreaded operation.
If your DLL will export data, the procedures must be compiled and linked consistently. Consistently use the same
/align
option for the DLL export procedure and the application that references (imports) it. The goal is to specify padding to ensure that exported data items are naturally aligned, including common block data items and structure element alignment (structures in a module).
If you need to specify linker options, place them after the
/link
option on the ifort command line.
Build the application. For example, if your DLL exports a common block containing four-byte variables, you might use the following command line (specify the
/dll
option):

ifort /align:commons /dll dllfile.for

  DUMPBIN /exports file.dll