Re: GPL traitor !

[Alan Mackenzie]

In gnu.misc.discuss Hyman Rosen <hyrosen@mail.com> wrote:
> Alan Mackenzie wrote:
>> In (ii), the new code generator is an extension of GCC, using its data
>> structures, conventions etc.  This new code, if it is released, must be
>> released under the GPL.  Just how it's slotted into the existing GCC is
>> immaterial.

> You are wrong. Extensions fall under the GPL only if they incorporate
> GPLed code within them by inclusion, not by reference.

The notion of "inclusion" doesn't make sense when talking about computer
programs.  Tell me, is an intricate C Macro "included in" or "referred to
by" the extension?  What about a data structure it uses?

> That is, if the extension is written by taking existing code and
> modifying, it falls under the copyright of the existing work (and is
> a derivative work as well, ....

Yes.

> ..., so that the GCC copyright holders could not use it without the
> permission of its author).

Yes, sort of.  But the new author is not licensed to distribute his
derivative work at all, except under the GPL.

> If the extension is written as a separate new work, it does not fall
> under the GPL, even if it makes extensive use of GPLed header files
> and of data structures that appear in the GPLed code.

In that case, the extension is derived from the source code of the data
structures, and thus isn't a "separate" new work.

> Attempting to use copyright to prevent interoperability is considered
> by the courts to be a serious breach, and is not allowed.

Hey, that's quite artistic, Hyman!  :-)  Interoperability has nothing to
do with what's been discussed so far.

One of the central aims of the GPL is to promote interoperability, as
you're well aware.

-- 
Alan Mackenzie (Nuremberg, Germany).