possible license issue (documentation generated from source) in MELT branch of GCC

[Basile Starynkevitch <basile at starynkevitch dot net>]

Dear Sir,

[adressed to licensing@fsf.org & gcc@gcc.gnu.org]

[I assume you understand both GPL vs GFDL licenses & software
architecture]

I am a (write after approval) contributor to GCC, and the author of the
MELT branch of GCC (on which I am working since 2008 at least). So far,
I am the only contributor to that branch. I am covered by a copyright
assigment RT206238 (from my employer CEA to FSF). 

I am not at all a lawyer, just a plain research engineer, computer
scientist, working in a public French research organization (CEA,
www.cea.fr, approximately the French variant of the US DOE) and I don't
understand US particularities about licenses. I am French so do not
understand, use or know US laws.



In a few words, MELT is a lispy domain specific language, translated to
C code suitable for GCC, to write extensions to GCC (so an extension
coded in MELT is like a GCC plugin coded in C, except that the source
code is in my MELT dialect, not in C, and that the API gluing the MELT
extension to GCC is different & specific to MELT). MELT can be compiled
in principle as a GCC branch, or -by fetching only a few files from the
branch- it follows the GCC trunk (but I did not merge the trunk into
MELT since several weeks, for technical reasons).

MELT is bootstrapped, like GCC is. This means that the MELT translator
is written in MELT and generates its own C files (obviously, these
generated files are stored in the svn repository, exactly like generated
configure files are also stored there).

MELT [in the svn repository] is made of:

a. a runtime, coded in C, files gcc/melt-runtime.[ch] plus some few
changes w.r.t. gcc trunk in a few files (e.g. a few lines added to
gcc/toplevel.c)

b. the MELT translator, itself coded in MELT, files
gcc/melt/warmelt*.melt. These files have the same copyright comment as
every other GCC source file.

c. The C files machine-generated from the above (b) files, in
gcc/melt/generated/*.c. The copyright comment from (b) is mechanically
copied in these files.

d. extra MELT files illustrating some concrete extra GCC passes coded in
MELT, files gcc/melt/xtra*melt

e. an incomplete hand-written gcc/doc/melt.texi file documenting the
branch. This is a chapter of the GCC internals documentation (like
gcc/doc/gimple.texi is) and it is included from gccint.texi with
@include melt.texi


The MELT building procedure also generates in the build tree, from some
annotations inside the (b) sources files gcc/melt/warmelt*melt, a file
meltgendoc.texi; I asked on May 7th on the gcc list [in a detailed
message] http://gcc.gnu.org/ml/gcc/2010-05/msg00125.html for comments,
but did not get any answers. Later on, in the
http://gcc.gnu.org/ml/gcc/2010-05/msg00539.html thread, I was told that
generating a *texi file from (GPLv3+ licensed, FSF copyrighted) source
code could be incompatible with the GFDL license of gccint.texi.

More technical details appear in
http://gcc.gnu.org/ml/gcc/2010-05/msg00125.html so I won't repeat them
here. In particular, there is a link (to an attachment on the GCC wiki)
to the generated documentation in PDF.


The main point is that MELT is quite a big code (for a single coder),
and that the generated documentation, even if it is incomplete, buggy,
is the only reference documentation I have. Generating documentation
from source code is not a new practice (GTK did that for years).

What do you suggest me to do? (I would hope that future versions of GPL
or GFDL might permit generating document from source code, but they
won't come out soon).

Perhaps a solution could be to move all melt documentation outside of
the GCC internals documentation in the MELT branch, and to have a
meltdoc.texi documentation with a compatible license (someone suggest
using GPL for a documentation) and have it include both melt.texi &
meltgendoc.texi.

I certainly don't want (and probably legally cannot) to change any
license or copyright comment without permission probably from FSF (or
who else?).

Apparently, I was told that the current state of MELT documentation is
that it might have a conflict between GPL & GFDL and therefore might not
be redistributable, but I am not a lawyer at all and do not understand
at all these issues. My wish would be to have a documentation which some
linux distributions could provide & redistribute.

I would be very sad to lose all my (incomplete) documentation efforts.

I am waiting for your advices & would be happy to answer to any
technical questions. But I am not a lawyer, and not even a native
English speaker.

Respectful regards.

 
-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mines, sont seulement les miennes} ***