Until early 2009 [1], FSF forbade anyone from creating a plug-in
architecture for GCC. I mean, you could do it, but it would not be
integrated upstream, since FSF policy is to have copyright assigned to them
before they integrate your changes into the project. If you were to create
a plug-in architecture for GCC and sign the copyright over to them, then
they could just sit on the code until GCC evolved to the point where your
plug-in architecture's interfaces no longer matched GCC's. See the GCC
Plug-ins Wiki page for the following ace quote: *So, how do we permit
plugins while prohibiting proprietary plugins, and how do we do it while
staying within the bounds of copyright law which is the basis of the
GPL?*[2] In a nutshell, FSF dislikes DRM, so their solution is to
create their
own DRM system.
Increasingly, this political position is more and more irrelevant. Computer
tools are so clever now that GPL v2 is simply not strong enough to mean
anything in the sense FSF originally intended. It is so extremely sad that
*compiler developers* do not understand that they can't truly complicate
proprietary plug-ins simply by unstable plug-in API. Once a shop has
developed enough plug-ins and value, there will be an inflection point
reached where it will make more sense to create a module matching tool [3]
that defines interface relations [4]. Compiler developers should understand
this: a plug-in API primarily separates functionality (what the plug-in
does) from integration (how the plug-in is connected to the core). At best
an unstable plug-in API can be a performance overhead inconvenience, but
with tools like distcc you can just map out your code to many cores.
It goes without saying that Richard Stallman is incredibly closed-minded and
visionary. [5] has the a picturesque definition [6].
See also my comments in [7] and Thomas Lord's follow-up on the same page in
the thread.
[1] http://www.sdtimes.com/link/33218
[2] http://gcc.gnu.org/wiki/GCC_Plugins
[3] http://www.cl.cam.ac.uk/~srk31/research/papers/kell09mythical.pdf**
[4] http://www.cl.cam.ac.uk/~srk31/research/papers/kell10component.pdf
[5] http://www.wired.com/magazine/2010/04/ff_hackers/all/1
[6] Time has not softened him. In our original interview, Stallman said,
“I’m the last survivor of a dead culture. And I don’t really belong in the
world anymore. And in some ways I feel I ought to be dead.” Now, meeting
over Chinese food, he reaffirms this. “I have certainly wished I had killed
myself when I was born,” he says. “In terms of effect on the world, it’s
very good that I’ve lived. And so I guess, if I could go back in time and
prevent my birth, I wouldn’t do it. But I sure wish I hadn’t had so much
pain.”
[7] http://lambda-the-ultimate.org/node/3696#comment-52599
On Thu, Jun 24, 2010 at 1:23 AM, Casey Ransberger
casey.obrie...@gmail.comwrote:
Whoa, okay. Have to ask. GCC has an intermediate representation that's
intentionally hard to work with, and you're saying that Stallman did this as
a political blockade?
I was under the impression that Clang got started up because some folks
found GCC to be too crufty, not too political. This doesn't seem to make
sense to me. Maybe I'm missing some context? Can you cite your sources or
elaborate on your point?
On Jun 23, 2010, at 2:25 PM, John Zabroski johnzabro...@gmail.com wrote:
This is not entirely true. Basile Starynkévitch has written GNU MELT [1]
as a way to circumvent hard to work with internal representation of GCC by
letting you create GCC plug-ins in a Lisp dialect. This basically
side-steps the traditional political blockade set-up by RMS. It is very
clever, and starting to mature; Basile has fixed a number of issues in how
he generates C code.
I'm not sure about Gerry Jensen's idea, e.g. how much effort, whether it is
worth the effort, etc.
Creating a VM for legacy code is also difficult, since it will run rather
slow unless you are a really good implementor (for example, the Hercules VM
[2] for simulating IBM mainframes is rather slow last I checked due to how
it has to intercept and translate instructions into the native
architecture).
[1] http://gcc.gnu.org/wiki/MiddleEndLispTranslator
http://gcc.gnu.org/wiki/MiddleEndLispTranslator
[2] http://www.hercules-390.org/http://www.hercules-390.org/
On Tue, Jun 22, 2010 at 11:37 AM, Monty Zukowski mo...@codetransform.com
mo...@codetransform.com wrote:
GNU C was explicitly designed to make its intermediate representation
hard to work with. LLVM is a more practical choice.
Monty
On Mon, Jun 21, 2010 at 6:02 PM, Gerry J geral...@tpg.com.au
geral...@tpg.com.au wrote:
You may find the concept of semantic slicing relevant:
http://www.cse.dmu.ac.uk/%7Emward/martin/papers/csmr2005-t.pdf
http://www.cse.dmu.ac.uk/~mward/martin/papers/csmr2005-t.pdfhttp://www.cse.dmu.ac.uk/%7Emward/martin/papers/csmr2005-t.pdf
There is software at:
http://www.cse.dmu.ac.uk/%7Emward/fermat.html
