[Vm-dev] Pragmas in VMMaker (was: Cryptography plugins

[Levente Uzonyi]

On Wed, 21 Jul 2010, David T. Lewis wrote:

>
> On Wed, Jul 21, 2010 at 12:42:06AM -0700, Andreas Raab wrote:
>>
>> On 7/20/2010 7:10 PM, David T. Lewis wrote:
>>> The current VMMaker for SqueakVM does not use or support pragmas
>>> (method annotations). Converting to pragmas makes VMMaker unloadable
>>> in older Squeak images.
>>
>> But these Squeak images won't run on the generated VM either. There is a
>> point and a time when it's worthwhile to move forward and given that
>> we've just hit a new major version in Squeak it seems quite reasonable
>> to say that the VMMaker 4 series requires Squeak 4 to run on.
>
> Actually many older images do run on the latest VMs. I frequently
> run Squeak 3.6 (and sometimes Squeak 2.4) on the latest VM whenever
> I want to look at older versions of methods to figure out how they
> were originally intended to work. I do expect these older images
> to run on newer VMs to the extent possible.

That's a nice feature. I think I didn't try running anything older than 
3.6 on the 4.0.x SqueakVM. IIRC some numbered primitives were reused, so I 
don't expect current VMs to function correctly with older images. I 
usually run then with their own VMs.

>
> I regularly run VMMaker in a 3.8 image, and I always run that image
> on the latest generated VM. But the only real reason I do that is
> to verify some degree of backward compatibility for VMMaker updates,
> so I don't really know if this matters to anyone else.
>
> Certainly for most of the folks on this list, doing VM work in
> a recent Squeak, Pharo, or Cuis image is a reasonable expectation.
> On the other hand, there may still be people who for various reasons
> prefer to use other images, and it would be nice if the most up to
> date VMMaker remains loadable in those images where possible.
>
> If anyone on the list *does* know of a need for VMMaker to work
> on images that do not support pragmas, please speak up now so we
> do not cause unnecessary problems.
>
> I am also curious about the motivation for using method annotations
> here. Is it a style preference, or is there a functional benefit?

I think the biggest benefit is the separation of declarations and 
slang code.


Levente

>
> Dave
>
>