Re: Progress on GCC plugins ?

[Alexandre Oliva <aoliva at redhat dot com>]

On Nov 24, 2007, Diego Novillo <dnovillo@google.com> wrote:

> Alexandre Oliva wrote:
>> On Nov 15, 2007, Diego Novillo <dnovillo@google.com> wrote:
>> 
>>> If/when your pass reaches certain maturity, you think it's ready for
>>> production, and people think it's a good idea to have it in the
>>> compiler, then you convert it into a static pass and you go through
>>> the traditional bootstrap process.
>> 
>>> That's the core idea with plug-ins, they allow more flexibility for
>>> experimentation.  They are not a means for implementing permanent
>>> features in the compiler.
>> 
>> I find the two paragraphs above contradictory.  If they're not means
>> for implementing permanent features, then converting a pass
>> implemented as a plugin that's ready for production into a static pass
>> is what?

> Converting a pass implemented as a plug-in into a static pass is the
> way to add permanent feature in the compiler.  In principle, I don't
> think we'll want to implement permanent features as plug-ins.

Agreed.

>> It raises an issue of how important it is that this plugin
>> architecture, if it is to exist, be similar to the internals of GCC,
>> such that the conversion is as simple as possible.

> There is no conversion.

Then I guess I don't see any value whatsoever in this particular
plugin architecture in overcoming the difficulties unexperienced GCC
developers face :-(

> Plug-in code uses the same internal code as statically linked
> passes.

Then they can be means for implementing permanent features in the
compiler, after all.  I guess we can agree on that ;-)

-- 
Alexandre Oliva         http://www.lsd.ic.unicamp.br/~oliva/
FSF Latin America Board Member         http://www.fsfla.org/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}