Re: Contributing LLVM.org patches to gud.el

[David Kastrup]

"Perry E. Metzger" <address@hidden> writes:

> On Wed, 11 Feb 2015 18:13:30 -0500 Richard Stallman <address@hidden>
> wrote:
>>   > But I believe you have asked in the interim that GCC not be
>>   > made more modular out of fear of proprietary reuse of the front
>>   > or back end.
>> 
>> If you are talking about outputting ASTs, that has nothing to do
>> with how modular GCC is.  This is a different issue.
>
> If this is the case, returning to an earlier issue:
>
> It might not per se necessary that Emacs have access to the AST in
> textual form. If GCC or part of GCC could be called as a library from
> within Emacs to access the AST via an API, that might be sufficient.

I'm reminded of a talk in a "fuzzy logic" conference I was in at one
time.  The resume from the authors was more or less that their novel
compression method achieved something like 20% of the signal theory
theoretical maximum performance, so if they got 10 times the funding,
they should be able to achieve about 200% of the theoretical maximum.

There is a principal basic problem that we cannot overcome with any
trickiness: Emacs and GCC are two separate, independent applications.
_Any_ way in which we are able to combine them will have a point where
Emacs as an application ends and/or a point where GCC ends.  At those
points, we can swap in a different IDE from Emacs, and a different
compiler from GCC, and copyright will not come into play.

The GPL is a license based on copyright and nothing else.  Any
complication we design for combining GCC and Emacs is going to hit the
combination GCC/Emacs just as hard as everyone else.

> I don't yet have an opinion on whether it would be more or less
> convenient than having the AST in some other form, but it would
> certainly permit Emacs to have arbitrary access to semantic
> information about the program being edited.

AST or any other form: the problem will remain identical.  What works
for the separate applications Emacs and GCC will work equally well with
respect to copyright by replacing one of the components.

So it is a waste of time thinking up ways to obfuscate the issue.  The
principal boundary condition of combining GCC and Emacs is that we have
two identifiable entities that are separate with regard to their
copyright.  What works for them, works for other entities with separate
copyright.

-- 
David Kastrup