[squeak-dev] A reengineering the CompiledMethod trailers

Igor Stasenko siguctua at gmail.com
Sun Dec 13 23:45:32 UTC 2009

2009/12/14 Ken G. Brown <kbrown at mac.com>:
> Not sure how this relates exactly but there has been quite a bit of work in the past re: Virtual Image 4.0 format.
> See:
> New Compiled Method Format
> <http://wiki.squeak.org/squeak/750>
> and:
> VI4 project
> <http://wiki.squeak.org/squeak/2119>
Oh, the changes in that project is much wider and requiring changing
the image format and VM.
My changes is much less significant and don't require rebuilding a whole image.
It is gradual change which doesn't changes the way how VM deals with
compiled methods,
but rather will change the way how tools (compiler/decompiler etc)
handing the compiled methods metadata encoding in trailing bytes.
And it backwards compatible with 99% of existing compiled methods.
Unless you start using new trailer kinds, it will remain the same.

> Here is an old related message from Tim Rowledge on Oct 20, 2005:
> At 1:23 PM -0700 10/20/05, tim Rowledge apparently wrote:
>>Delivered-To: list-squeak-dev at lists.squeakfoundation.org
>>From: tim Rowledge <tim at rowledge.org>
>>Date: Thu, 20 Oct 2005 13:23:20 -0700
>>To: The general-purpose Squeak developers list
>>       <squeak-dev at lists.squeakfoundation.org>
>>Subject: Re: new image format (was: Actually doing something!)
>>On 20-Oct-05, at 1:01 PM, Jecel Assumpcao Jr wrote:
>>>Tim Rowledge wrote on Wed, 19 Oct 2005 15:41:31 -0700
>>>>Squeak is about 10 years old. Time to move from toddler to pre-
>>>>schooler at least. Yes, it will mean a break in being able to run old
>>>>images on new VMs. So what; old VMs will still be there. The
>>>>sourcecode is still on SVN.
>>>I guess this is a good time to ask about Anthony Hannan's "image version
>>>4 format" work (http://minnow.cc.gatech.edu/squeak/VI4). Bryce Kampjes
>>>mentioned incompatibilities as the reason why this is no longer being
>>>considered for inclusion in Squeak, but reading all the documentation
>>>and scanning quickly through the sources the only thing I noticed was
>>>that the needed debugger changes were not finished. Am I missing
>>I don't know. Some of his work got included anyway (some prims to support closures and I think
>>continuations) other stuff is superseded and probably a lot is suffering from bitrot since I don't recall hearing from him in ages. Are you there AJH?
>>I'd like to see the closures being properly supported and made standard, whether through his code or other code. It really is a bit bad to still be without them. The page http://minnow.cc.gatech.edu/squeak/3717 is terribly out of date as well and Dan seems to have drifted off of this path. http://minnow.cc.gatech.edu/squeak/3718 is at least a year behind the times.
>>tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
> Ken G. Brown

Best regards,
Igor Stasenko AKA sig.

More information about the Squeak-dev mailing list