Re: [DotGNU]Licence question about GNU and GCC

[Norbert Bollow]

> I am a big supporter, fan and user of GNU software and
> want only the best for the project.

Great! :-)

> I am not trying to undermine the GPL, but point out a
> inherent danger that the SOAP and DOTGNU technology
> will open up all of the gpl'd code to. 

Ok.  But how is this danger greater than what was always
possible with GPL programs, to create input files for the GPL
program with a proprietary program and feed the data to
the GPL program with a pipe or a temporary file?

> This is one of the major worries of the GCC community
> when presented with the ideas of an XML representation
> of the ast. But it applies to all the other GPLed code
> when brought into a DOTGNU environment.

Yes... it applies to all GPL'd code, but it's not likely
to be a serious problem for most GPL'd code.  But in the
case of GCC there is a potentially serious strategic problem,
of giving proprietary compiler vendors a gratis optimizing
super-assembler.

If emitting an XML representation of an AST is significantly
easier for them or more efficient than emitting C code, then
there is reason for concern that the AST-XML approach might
in fact effective weaken GCC's copyleft.  But if proprietary-
minded users of your work would get no significant advantage
over using C code as a intermediate representation (which is
something that they can do anyway) then perhaps you don't
need to worry so much.  (My understanding of compiler
internals and AST in particular is not sufficiently in-depth
to judge whether this is a matter that one should be really
concerned about or not.)

> The interest that I have in the gcc compiler is to
> bring what you have with c# and java to the c world.
> Reflection, Introspection, Serialization.

Definately a worthwhile goal.

> I am prototyping my GCC extension in perl, because of
> the nature of the enviroment, it gives you access to
> all types of interesting information about the running
> program. For me to connect the perl code to the GCC
> via an XML representation of the AST is very clean and
> easy to debug. I can imagine that some of work that I
> am doing will be interesting to the DOTGNU program. 
> 
> The possibility to use the GCC as a front-end on the
> ast level and not on the rtl level has not been
> discussed yet. Maybe it would be of benifit to the
> DOTGNU?

You mean, use (parts of) gcc to create an AST and then
use pnet to translate the AST into bytecode?  I note
that http://gcc.gnu.org/projects/ast-optimizer.html
talks only about C and C++.  Are there other languages
where gcc also translates entire functions into an AST?

C and C++ are for language reasons very difficult to
compile to verifiable bytecode, and this is a problem
that we can't get around by starting from an AST instead
of starting from source code.

Greetings, Norbert.

-- 
A founder of the http://DotGNU.org project and Steering Committee member
Norbert Bollow, Weidlistr.18, CH-8624 Gruet   (near Zurich, Switzerland)
Tel +41 1 972 20 59       Fax +41 1 972 20 69      http://thinkcoach.com
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