Re: Progress on GCC plugins ?

[Andrew Haley <aph at redhat dot com>]

Ian Lance Taylor writes:
 > Andrew Haley <aph@redhat.com> writes:
 > 
 > >  > Most new gcc back-ends are private, so I don't buy that part of the
 > >  > argument.  And in any case nobody is talking about plug-ins for gcc
 > >  > backends.  We're talking about plugins at the tree/GIMPLE level.
 > > 
 > > Yeah, I know.  I'm thinking about proprietary compilers (not just 
 > > back-ends, optimization passes) bolted on to a gcc front-end to get
 > > Linux compatibility.
 > 
 > As we've discussed previously, we are already seeing that without
 > plugins: GCCfss.  Sun took gcc's frontend and attached it to their
 > proprietary backend.  So in my view introducing plugins will not make
 > a substantive difference here.

Well, yeah, but no-one ever said it wouldn't be possible without
plugins.

 > >  > When I was in the business of convincing people to pay for gcc
 > >  > work, I had a laundry list of general gcc improvements to sell.  I
 > >  > was never able to get a dime except for target specific
 > >  > improvements.  A plugin architecture would not make any difference
 > >  > to that kind of work.
 > > 
 > > No, but it might mean that entire gcc ports go away, as people who
 > > already have in-house compilers use them with a gcc front-end for
 > > Linux ports, rather than funding gcc ports.
 > 
 > But as you know, most gcc ports are never contributed anyhow.

Sure, but they are still free software: if the compiler gets
distributed, so does its source code.  Of couse, assigning copyright
to FSF is nice, but freedom is much more important.

 > Ports that people hire Red Hat to do are contributed, but I can
 > easily count six gcc ports I've seen myself that were never
 > contributed. 

 > So again I don't see a substantive difference here.

I guess it depends on what you mean by "substantive".  As I said, I
suspect that if it were easier to decouple the gcc front-end from the
back-end and to maintain the resulting compiler, there would be fewer
free compilers.  And no, neither of us can prove it without doing the
experiment.  I insist, however, that when it comes to a change that
potentially reduces freedom, the burden of proof -- or at least of
evidence -- is on those wanting to make the change.

Andrew.

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