[Vm-dev] Cog VMMaker dependencies

[David T. Lewis]

On Mon, Jan 31, 2011 at 03:08:09PM +0100, Igor Stasenko wrote:
>  
> On 31 January 2011 14:43, David T. Lewis <lewis at mail.msen.com> wrote:
> >
> > On Mon, Jan 31, 2011 at 02:02:30PM +0100, Igor Stasenko wrote:
> >>
> >> Hello
> >>
> >> i am trying to put everything together and load all VMMaker stuff into
> >> clean image, and found that it depends on
> >> ???BochsIA32Alien class, defined in Cog package.
> >> But this package have no public repository and can be found only in
> >> vmmaker image which saved by Eliot in SVN repo :(
> >>
> >> Guys, do you mind if i copy this package to VMMaker repository on
> >> squeaksource, so then we could have an official place where to
> >> download it.
> >> Because clearly, we need to make sure that VMMaker could be loaded
> >> into fresh image from scratch, and in order to do that, we need some
> >> persistent public place where we can download all packages from.
> >
> > Funny, I was looking at exactly the same thing yesterday. The Alien
> > project on SqueakSource provides the NewsqueakIA32ABIPlugin and puts
> > it in package 'Alien-VMMaker-Plugins'. This is also present in the
> > oscog image but recategorized to 'VMMaker-Plugins-Alien', which
> > also contains the new IA32ABIPlugin distributed with Cog. The
> > BochsIA32Plugin plugin is in 'Cog-ProcessorPlugins'.
> >
> > The IA32ABIPlugin and BochsIA32Plugin are not yet usable in the
> > standard VMMaker package (though I hope to correct this after the
> > current round of VM builds). NewsqueakIA32ABIPlugin builds cleanly
> > on Linux, though I have no idea if the resulting plugin does anything
> > useful.
> >
> > I'm assuming that BochsIA32Plugin is at least loosely related to the
> > current Alien development in Cog, so my personal preference would be
> > to store IA32ABIPlugin and BochsIA32Plugin in the SqS/Alien project.
> > The project seems to be actively maintained, and it already serves
> > as the source for NewsqueakIA32ABIPlugin (I have it linked to VMMaker
> > through the configure map). Would that approach be workable?
> >
> 
> It would be good if VMMaker or plugins above to be not depend on Alien.
> Alien is an image-side package, which having no use when building VM,
> except some constants (i think).
> So, what should be done is to split Alien to Alien + Alien-pool, in
> same way as it done with FFI,
> to decouple VMMaker from FFI image-side code.
> 
> > As an aside, I do think it is a good thing for plugins that are
> > actively maintained to live in their own projects. Once they land
> > in VMMaker, they tend to become homeless children ;)
> >
> 
> Yes, things are messy..
> the problem now is, that Cog's VMMaker now depends on Cog package,
> while Cog package in own turn depends on VMMaker
> (SmartSyntaxInterpreterPlugin etc).
> A classic circular dependency between packages :))
> 
> So, what is the right place for putting a Cog package?
> In VMMaker or in Alien repository?
> 
> So, certainly, some classes should change their home package to avoid
> circular dependency,
> and to have a good load order, like we had in old VMMaker:
> 
> - FFI & Sound pools
> - VMMaker
> - rest of stuff
> 
> 
> P.S. by exploring the Cog package contents, i don't feel that it
> belongs to Alien repository.
> Btw, few weeks ago i hacked BochsIA32Alien class to remove
> dependencies from Alien and Boch plugins both.
> So, it can generate the code in simulator, but of course can't execute
> it nor disassemble it.

Ah, I see what you mean now. I was referring only to 'Cog-ProcessorPlugins',
which contains just the BochsIA32Plugin. But there are a number of other
things of interest in package 'Cog'. Perhaps Eliot can offer some guidance
here, I don't know how or where this package should be maintained. If the
intent is to maintain all of category 'Cog' as a package, then putting it
in the VMMaker project might make better sense.

Dave