1127489 - A question about GPLv2 licensing and Emscripten pthreads implementation?

Status: RESOLVED FIXED

(mozilla.org :: Licensing, task)

Description

[Jukka Jylänki]

Emscripten is a Mozilla-developed BSD-licensed open source compiler for converting C/C++ code to JavaScript: http://emscripten.org/. I am in the process of implementing pthreads support to Emscripten, so that native code that uses multithreading can be ported over to run in JavaScript. Now, I found this project called Open POSIX Test Suite at http://posixtest.sourceforge.net, which has a very extensive set of tests for testing the conformancy of a pthreads implementation. Looking at the test suite, I think it would be very useful for finding bugs in the pthreads implementation I'm developing for Emscripten. However, the Open POSIX Test Suite is licensed under GPLv2, and Emscripten is BSD, which raises a question: if I used the test suite to find and fix bugs in the Emscripten pthreads implementation, would that require distributing the Emscripten pthreads implementation under GPLv2 as well, or is the pthreads implementation free from such restriction?

My understanding is that the GPLv2 licensing requirement would not apply to Emscripten pthreads implementation, since the unit test suite would not be part of the distributed implementation, and the pthreads implementation is not derivative work of the unit test suite. My understanding is that only any modifications I do to the test suite itself should be made public under GPLv2, but the pthreads implementation itself does not. I'm looking at what I think is the related clause in GPLv2, which reads

   "Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does."

Is my interpretation correct? Am I ok to proceed with this work?

Comment 1

[Jukka Jylänki]

Err, sorry about the BSD license, I don't know where I got that from. The Emscripten license can be found here: http://kripken.github.io/emscripten-site/docs/introducing_emscripten/emscripten_license.html

Comment 2

[Gervase Markham [:gerv]]

Yes, your understanding is correct. It is OK to both test Emscripten against this test suite, and also OK to check it in to a (clearly demarcated) area of the Emscripten source code repo, if you wish. Neither of these things would make Emscripten subject to the terms of the GPL.

Gerv