CODEWITHSUNDEEP
fortranshared-librariesstatic-librariesobfuscation
apetros85
apetros85

Reputation: 461

Share Fortran library without revealing source code

I have a software developed in-house. It is written in Fortran and consists of 3 kinds of files: 1) the solver files, 2) the models' files and 3) a file where the models used are defined. The solver also uses some libraries namely lapack and HSL ma41. Usually, I select the needed models for the user, compile all together and provide an executable.

I want to allow users to add their own models or modify the existing ones without being able to change/modify/see the solver source code.

One thought was to compile the solver into an object file. Then the user would compile the definition file and his models and link them together with the libraries. Is that possible? I guess then the user must have the same platform as the one the solver was compiled on? (ie Intel compiler on Windows 64-bit) So I'll need to built a library for any possible combination OS/hardware/compiler?

Another idea is to send the solver source also but use obfuscation. I can't find any tested/reliable solutions for that online? Is it a good option?

Thanks in advance.

Upvotes: 2

Views: 483

Answers (1)

IanH
IanH

Reputation: 21451

You can distribute the object code in a library, as you propose. If the entry points for your code are in Fortran modules, then you also need to distribute the mod files (or equivalent for your compiler) that also result from compilation of the modules.

(If any of the entry points for your library code are external procedures then it is a convenience for your users if you provide interface blocks for those external procedures. These interface blocks can be in source form (the interface block contains no information beyond what your library's documentation would have to provide), or again could be pre-compiled into a module.)

Object code may be platform (architecture) specific, compiler specific, compiler version specific and in some cases compile options specific. Careful design and specification of the interface between your solver and the clients models can mitigate some of the potential variation. For example - many platforms have a well defined (perhaps through explicit specification or near ubiquitous convention) C application binary interface, so interfaces described using the C equivalent are typically robust, at the cost of significant loss of capability over a common-processor Fortran to Fortran interface.

Upvotes: 2

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