FORTRAN 95: is it possible to share a module without sharing the source code?

Question

I would like to be able to share a FORTRAN 95 module without sharing its source code. Is it possible to do so (maybe by sharing the .MOD file)? In case this is relevant, I use Silverfrost FTN95 compiler on Plato. So far, I only manage to make this work by using the source code of the external module. Here is an example:

---

file: module_test.f95

module TEST
contains

  subroutine 1
  code...

end module TEST

---

file: main_program.f95

include "module_test.f95"
program MAIN_PROGRAM
use TEST
implicit none

code...

end program MAIN_PROGRAM

---

So, would it be possible for someone to use my module TEST without having my file module_test.f95 nor the line include "module_test.f95" on the main code?

Thanks a lot!

Answer 1

You could provide two things. 1) Compiled object code, possibly in library form. The disadvantage is that this would depend on compiler, OS, perhaps compiler version, and so could be large burden to support. 2) Instead of providing the source code so that others could use the module, you could write equivalent interface descriptions of your routines. This, at least, is at the source code level and would not be compiler dependent. It would some work to write and would have to be maintained if you changed the arguments of any of your procedures.

Answer 2

The solution I am using is, as M. S. B. recommended, to compile the module in library form. I am explicitly showing how I am doing this in case this might be helpful to someone, as this is what I did not know in those days.

First, one needs to compile the module module_test.f95. Using the gfortran compiler, this can be accomplished by the command gfortran -c module_test.f95. This will create two files, module_test.o and module_test.mod. These are the compiled module files that can be shared without sharing the source code.

Now to the main program. For it to make use of the module, one still needs to add the line use TEST but no include <source code>:

program MAIN_PROGRAM
use TEST
implicit none

<...code...>

end program MAIN_PROGRAM

Now when compiling the main program, one must include the location of the .o module file in the command. In the case above, it would be gfortran main_program.f95 module_test.o (supposing that module_test.o is on the same folder as the project). This will compile the main program using the module without the need for its source code.