Re: What exactly is the licensing situation with GNAT?

[Simon Wright <simon@pushface.org>]

Hubert <herrdoktor@fumanchu.com> writes:

> Ok, I was wondering about that for a while, hence my question about
> the GPL situation with the libraries. I was under the impressino that
> the thing that makes the resulting program GPL was the libraries and
> not the compiler, but this explains now why any output from the GPL
> compiler is GPL if the runtime that is essential to run the compiled
> program is also GPL.

GCC itself has always been GPL; WindRiver, for example, have always
provided GCC as one of the compilers their customers could use to build
proprietary applications.

To quote from the GNU Licences FAQ[1],

   The GCC Runtime Library Exception covers libgcc, libstdc++,
   libfortran, libgomp, libdecnumber, and other libraries distributed
   with GCC. The exception is meant to allow people to distribute
   programs compiled with GCC under terms of their choice, even when
   parts of these libraries are included in the executable as part of
   the compilation process.

and from the GCC Runtime Library Exception Rationale[2],

   [...]  the FSF decided long ago to allow developers to use GCC's
   libraries to compile any program, regardless of its
   license. Developing nonfree software is not good for society, and we
   have no obligation to make it easier. We decided to permit this
   because forbidding it seemed likely to backfire, and because using
   small libraries to limit the use of GCC seemed like the tail wagging
   the dog.

This is why the FSF GCC Ada runtime _does_ carry the Runtime Library
Exception.

The last sentence is, of course, borne out by this present row.

> The whole situation is not so easily understood and the explanation in
> the Libre Adacore package don't make it much clearer either. I was
> thinking if it is the Libraries only, one could omit them and write a
> new set of libraries, but this essentially rules that out.

For info, which explanation? I've certainly heard what I considered to
be misleading statements on this from AdaCore, but that could well have
been because they were trying to persuade management and I was only
present as technical assistance.

You could write a new set of libraries (probably working from the FSF
compilers) but that would be a large task (mammoth if you started from
scratch, and moreover a moving target).

[1] http://www.gnu.org/licenses/gpl-faq.html#LibGCCException
[2] http://www.gnu.org/licenses/gcc-exception-faq.html