Re: filebench: bison generated parser + CDDL

[Martin Steigerwald]

Am Mittwoch, 4. Juli 2012 schrieb Akim Demaille:
> Hi all,

Hi Akim and Brett,

> I have added Bret in CC, as he is the one to deal with licenses
> and exceptions.

Any progress?

Thanks,
Martin

> 
> Le 3 juil. 2012 à 09:47, Martin Steigerwald a écrit :
> > Please keep Cc, as I am not subscribed to help-bison or
> > filebench-developers.
> > 
> > 
> > 
> > Dear bison developers, dear FSF licensing team, dear filebench
> > developers,
> > 
> > Alex Mestiashvili and I have packaged filebench for Debian. But now I
> > wonder whether we may legally distribute it.
> > 
> > Bison uses a bison generated parser from parser_gram.y and these
> > generated
> > 
> > files are:
> > | Files: parser_gram.c parser_gram.h
> > | Copyright: 1984, 1989, 1990, 2000-2011 Free Software Foundation, Inc.
> > | 
> > |  C LALR(1) parser skeleton written by Richard Stallman, by
> > |  simplifying the original so-called "semantic" parser.
> > | 
> > | License: GPL-3+ with exception
> > | This package is free software; you can redistribute it and/or modify
> > | […]
> > | As a special exception, you may create a larger work that contains
> > | part or all of the Bison parser skeleton and distribute that work
> > | under terms of your choice, so long as that work isn't itself a
> > | parser generator using the skeleton or a modified version thereof
> > | as a parser skeleton.  Alternatively, if you modify or redistribute
> > | the parser skeleton itself, you may (at your option) remove this
> > | special exception, which will cause the skeleton and the resulting
> > | Bison output files to be licensed under the GNU General Public
> > | License without this special exception.
> > | .
> > | This special exception was added by the Free Software Foundation in
> > | version 2.2 of Bison.
> > 
> > Is this compatible with CDDL-1?
> 
> If you fall into case one (you just "use" Bison the regular way),
> yes it is (IANAL, but that was a design goal when the exception
> was designed: Bison's output _can_ be used to produce proprietary
> software)
> 
> > As far as I understand CDDL-1 and GPL are not compatible, but when I read
> > this special exception correctly, in the case that no new parser
> > generator is done any terms, any license can be used for the resulting
> > work.
> > 
> > I asked this already on debian-legal and got an IANAL response back that
> > indicates that the exception could be interpreted from its intent or its
> > wording and this gives different results as to the redistributability of
> > the software – see below.
> > 
> > Dear FSF licensing team, dear bison developers, can you elaborate on
> > that?
> > 
> > If its not clearly redistributable then what changes could make it so?
> > 
> > Thanks,
> > Martin
> > 
> > 
> > ----------  Weitergeleitete Nachricht  ----------
> > 
> > Betreff: Re: filebench: bison generated parser + CDDL
> > Datum: Samstag, 2. Juni 2012, 22:29:41
> > Von: Mark Weyer <address@hidden>
> > An:  address@hidden
> > 
> > On Fri, Jun 01, 2012 at 01:45:06PM +0200, Martin Steigerwald wrote:
> >> Am Montag, 7. Mai 2012 schrieb Mark Weyer:
> >>> Just a quick note: If you are right about the incompatibility of CDDL-1
> >>> and GPLv3 (others on this list will know if you are), then the
> >>> combined work is non-free: Its license terms discriminate against a
> >>> field of endeavour, namely developing a parser generator.
> >> 
> >> I don´t understand this.
> >> 
> >> I understand the exception
> >> 
> >> | As a special exception, you may create a larger work that contains
> >> | part or all of the Bison parser skeleton and distribute that work
> >> | under terms of your choice, so long as that work isn't itself a
> >> | parser generator using the skeleton or a modified version thereof
> >> | as a parser skeleton.  Alternatively, if you modify or redistribute
> >> | the parser skeleton itself, you may (at your option) remove this
> >> | special exception, which will cause the skeleton and the resulting
> >> | Bison output files to be licensed under the GNU General Public
> >> | License without this special exception.
> >> 
> >> so that it allows distributing the software under any other license as
> >> long as the generated parser isn´t a parser generator in itself.
> >> 
> >> I don´t think that the parser in here is a parser generator. As far as I
> >> understand parser_gram.c and parser_gram.h just parses loadable workload
> >> descriptions.
> 
> Really, parse-gram.[ch] are invisible internal details about the
> implementation of Bison, that's not what we are referring to.
> "Skeletons" are the templates that are in data/ (yacc.c, glr.c,
> etc.) which are parameterized by bison (the executable).  The
> exception is designed to state that as long as you use Bison
> as is, you don't have constraints.  But if you modify skeletons
> or Bison itself, then the GPLv3 applies without the exception
> clause.
> 
> > It is less clear than I thought.
> > 
> > Let A be a work with a parser generated by bison and assume that A is not
> > a parser generator. It appears that the exception allows the authors of
> > A to place A under any license they want to, effectively overriding the
> > GPL-and-exception. Suppose they choose something like the MIT license.
> > Then they, or someone else, retrieves the parser skeleton (now under the
> > MIT license) from A and uses it as a parser skeleton for a commercial
> > parser generator B. The exception is clearly not intended to allow that.
> > Reading its letter, I do not see that it actually achieves that intent.
> 
> Skeletons are really dynamic, they are not plain files with
> simple substitutions, they are "run" by M4.  So this scenario
> does not make sense in practice, IMHO.
> 
> > How I read the exception on May 7, I thought that it would not be deleted
> > by relicensing, but that its requirement would persist in all modified
> > version of A. Which is the only way (I can see) that the exception
> > achieves its intent.
> > 
> > The true question is, of course, whether a court would judge in favour of
> > the exception's letter or its intent.
> > 
> > If it judges in favour of its intent: Taking the CDDL'ed filebench for A
> > and some modified version B of A, by copyleft (of both the
> > GPL-and-exception and the CDDL) we have the same license situation in B
> > as in A. Now if B is as above, the exception is not applicable and thus
> > (assuming that GPL and CDDL are incompatible) B is not distributable.
> > Thus the combined licenses forbid distribution of (some) modified
> > versions and the package is non-free.
> > 
> > If the court judges in favour of the exception's letter, then your
> > upstream can put parser_gram.c and parser_gram.h under the CDDL and
> > everything is fine (You can't do that yourself, because
> > A: the exception grants that right only to the creator of the larger work
> > and B: if upstream does not exercise the right of the exception, then
> > they do not
> > 
> >   have the right to distribute filebench under anything other than the
> >   GPL.)
> > 
> > I am not a lawyer, this is not legal advice, et cetera.
> > 
> >  Mark Weyer
> > 
> > --
> > To UNSUBSCRIBE, email to address@hidden
> > with a subject of "unsubscribe". Trouble? Contact
> > address@hidden Archive:
> > http://lists.debian.org/address@hidden
> > 
> > 
> > -------------------------------------------------------------
> > 
> > Ciao,


-- 
Martin Steigerwald
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