[Vm-dev] VM Maker: Cog-eem.230.mcz

[commits at source.squeak.org]

Eliot Miranda uploaded a new version of Cog to project VM Maker:
http://source.squeak.org/VMMaker/Cog-eem.230.mcz

==================== Summary ====================

Name: Cog-eem.230
Author: eem
Time: 22 December 2014, 1:48:33.304 pm
UUID: 24969f5e-e5a9-49a3-927e-28f5610df9f0
Ancestors: Cog-eem.229

Spur bootstrap:
Add SmallFLoat64>>identityHash.  Needs
VMMaker.oscog-eem.997.

Change ClassDescription>>updateInstancesFrom:...
to use forwarding become.  This is necessary if the
GC in ClassBuilder>>#update:to: is to be avoided.

=============== Diff against Cog-eem.229 ===============

Item was added:
+ ----- Method: SpurBootstrapPrototypes>>ClassDescriptionPROTOTYPEupdateInstances:from:isMeta: (in category 'method prototypes') -----
+ ClassDescriptionPROTOTYPEupdateInstances: oldInstances from: oldClass isMeta: isMeta
+ 	"Recreate any existing instances of the argument, oldClass, as instances of the receiver,
+ 	 which is a newly changed class. Permute variables as necessary, and forward old instances
+ 	 to new instances.  Answer nil to defeat old clients that expect an array of old instances.
+ 	 The old behaviour, which necessitated a global GC, exchanged identities and answered
+ 	 the old instances.  But no clients used the result.  This way we avoid the unnecessary GC,"
+ 	| map variable instSize newInstances |
+ 
+ 	oldInstances isEmpty ifTrue:
+ 		[^nil]. "no instances to convert"
+ 	isMeta ifTrue:
+ 		[(oldInstances size = 1
+ 		  and: [self soleInstance class == self]) ifFalse:
+ 			[^self error:'Metaclasses can only have one instance']].
+ 	map := self instVarMappingFrom: oldClass.
+ 	variable := self isVariable.
+ 	instSize := self instSize.
+ 	newInstances := Array new: oldInstances size.
+ 	1 to: oldInstances size do:
+ 		[:i|
+ 		newInstances
+ 			at: i
+ 			put: (self newInstanceFrom: (oldInstances at: i) variable: variable size: instSize map: map)].
+ 	"Now perform a bulk mutation of old instances into new ones"
+ 	oldInstances elementsForwardIdentityTo: newInstances.
+ 	^nil!

Item was added:
+ ----- Method: SpurBootstrapPrototypes>>ClassDescriptionPROTOTYPEupdateInstancesFrom: (in category 'method prototypes') -----
+ ClassDescriptionPROTOTYPEupdateInstancesFrom: oldClass
+ 	"Recreate any existing instances of the argument, oldClass, as instances of 
+ 	 the receiver, which is a newly changed class. Permute variables as necessary,
+ 	 and forward old instances to new instances.. Answer nil to defeat any clients
+ 	 that expected the old behaviour of answering the array of old instances."
+ 	"ar 7/15/1999: The updating below is possibly dangerous. If there are any
+ 	contexts having an old instance as receiver it might crash the system if
+ 	the new receiver in which the context is executed has a different layout.
+ 	See bottom below for a simple example:"
+ 	self updateInstances: oldClass allInstances asArray from: oldClass isMeta: self isMeta.
+ 	"Now fix up instances in segments that are out on the disk."
+ 	ImageSegment allSubInstancesDo:
+ 		[:seg |
+ 		seg segUpdateInstancesOf: oldClass toBe: self isMeta: self isMeta].
+ 	^nil
+ 
+ "This attempts to crash the VM by stepping off the end of an instance.
+  As the doctor says, do not do this."
+ "	| crashingBlock class |
+ 	class := Object subclass: #CrashTestDummy
+ 		instanceVariableNames: 'instVar'
+ 		classVariableNames: ''
+ 		poolDictionaries: ''
+ 		category: 'Crash-Test'.
+ 	class compile:'instVar: value instVar := value'.
+ 	class compile:'crashingBlock ^[instVar]'.
+ 	crashingBlock := (class new) instVar: 42; crashingBlock.
+ 	Object subclass: #CrashTestDummy
+ 		instanceVariableNames: ''
+ 		classVariableNames: ''
+ 		poolDictionaries: ''
+ 		category: 'Crash-Test'.
+ 	crashingBlock value"!

Item was added:
+ ----- Method: SpurBootstrapPrototypes>>SmallFloat64PROTOTYPEidentityHash (in category 'method prototypes') -----
+ SmallFloat64PROTOTYPEidentityHash
+ 	"Answer an integer unique to the receiver."
+ 	<primitive: 171>
+ 	^self primitiveFailed!