[Vm-dev] VM Maker: VMMaker.oscog-eem.1002.mcz

[commits at source.squeak.org]

Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.1002.mcz

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

Name: VMMaker.oscog-eem.1002
Author: eem
Time: 27 December 2014, 5:07:33.563 pm
UUID: 6b1f3f75-19bc-4453-be2f-bf7067898bbf
Ancestors: VMMaker.oscog-eem.1001

Send cannotReturn for sideways return attemps
when there's an unwind-protect.  Old code would
erroneously answer unwind-protect even if home
could not be found.

e.g. This should raise cannot return:

	| b |
	b := [ ^ 42 ].
	[ [b value] ensure: [1] ] fork.
	Processor yield

just as this does:

	| b |
	b := [ ^ 42 ].
	[ b value ] fork.
	Processor yield

=============== Diff against VMMaker.oscog-eem.1001 ===============

Item was changed:
  ----- Method: StackInterpreter>>findMethodWithPrimitive:FromContext:UpToContext: (in category 'handler search') -----
  findMethodWithPrimitive: primitive FromContext: senderContext UpToContext: homeContext
  	"See findUnwindThroughContext:.  Alas this is mutually recursive with
  	 findMethodWithPrimitive:FromFP:SP:ThroughContext: instead of iterative.
  	 We're doing the simplest thing that could possibly work.  Niceties can wait."
  	| theContext theMethod |
  	self assert: (senderContext = objectMemory nilObject or: [objectMemory isContext: senderContext]).
  	self assert: (homeContext = objectMemory nilObject or: [objectMemory isContext: homeContext]).
  	theContext := senderContext.
  	[theContext = objectMemory nilObject ifTrue:
  		[^theContext].
  	 self isMarriedOrWidowedContext: theContext] whileFalse:
  		[theContext = homeContext ifTrue: [^0].
+ 		 (primitive = 0
+ 		  or: [(objectMemory fetchPointer: ClosureIndex ofObject: theContext) ~= objectMemory nilObject]) ifFalse:
- 		 (objectMemory fetchPointer: ClosureIndex ofObject: theContext) = objectMemory nilObject ifTrue:
  		 	[theMethod := objectMemory fetchPointer: MethodIndex ofObject: theContext.
+ 			 (self primitiveIndexOf: theMethod) = primitive ifTrue:
- 			 (self primitiveIndexOf: theMethod) == primitive ifTrue:
  				[^theContext]].
  		 theContext := objectMemory fetchPointer: SenderIndex ofObject: theContext].
  	(self isWidowedContext: theContext) ifTrue:
  		[^objectMemory nilObject].
  	^self
  		findMethodWithPrimitive: primitive
  		FromFP: (self frameOfMarriedContext: theContext)
  		UpToContext: homeContext!

Item was changed:
  ----- Method: StackInterpreter>>findMethodWithPrimitive:FromFP:UpToContext: (in category 'handler search') -----
  findMethodWithPrimitive: primitive FromFP: startFP UpToContext: homeContext
  	"See findUnwindThroughContext:.  Alas this is mutually recursive with
  	 findMethodWithPrimitive:FromContext:ThroughContext: instead of iterative.
  	 We're doing the simplest thing that could possibly work.  Niceties can wait."
  	| theFP theFPAbove theSP theMethod senderContext |
  	<var: #startFP type: #'char *'>
  	<var: #theFP type: #'char *'>
  	<var: #theFPAbove type: #'char *'>
  	<var: #theSP type: #'char *'>
  	theFP := startFP.
  	theFPAbove := startFP.
  	[((self frameHasContext: theFP)
  	  and: [homeContext = (self frameContext: theFP)]) ifTrue:
  		[^0].
+ 	 (primitive = 0
+ 	  or: [self frameIsBlockActivation: theFP]) ifFalse:
- 	 (self frameIsBlockActivation: theFP) ifFalse:
  	 	[theMethod := self frameMethodObject: theFP.
+ 		 (self primitiveIndexOf: theMethod) = primitive ifTrue:
- 		 (self primitiveIndexOf: theMethod) == primitive ifTrue:
  			[theFP = theFPAbove
  						ifTrue: [theSP := self findSPOf: theFP on: (stackPages stackPageFor: theFP)]
  						ifFalse: [theSP := self frameCallerStackPointer: theFPAbove].
  			 ^self ensureFrameIsMarried: theFP SP: theSP]].
  	 theFPAbove := theFP.
  	 theFP := self frameCallerFP: theFP.
  	 theFP ~= 0] whileTrue.
  	senderContext := self frameCallerContext: theFPAbove.
  	(objectMemory isContext: senderContext) ifFalse:
  		[^objectMemory nilObject].
  	^self
  		findMethodWithPrimitive: primitive
  		FromContext: senderContext
  		UpToContext: homeContext!

Item was changed:
  ----- Method: StackInterpreter>>findUnwindThroughContext: (in category 'return bytecodes') -----
  findUnwindThroughContext: homeContext
  	"Search for either an unwind-protect (activation of method with primitive 198)
+ 	 or homeContext along the sender chain, which ever is found first.  Return values:
+ 		0			home context was found on sender chain with no intervening unwind-protects
+ 		nilObj		home context could not be found => cannotReturn
+ 		context		the context of an intervening unwind-protect implies home context was found"
- 	 or homeContext along the sender chain, which ever is found first.  If homeContext
- 	 is not found answer nilObj, indicating cannotReturn:.  If homeContext is found
- 	 answer 0.  If homeContext is itself an unwind-protect answer the context, not 0."
  	| ctxtOrNilOrZero theMethod |
  	"Since nothing changes we don't need to internalize."
  	ctxtOrNilOrZero := self findMethodWithPrimitive: 198 FromFP: framePointer UpToContext: homeContext.
  	ctxtOrNilOrZero = 0 ifTrue:
  		[theMethod := objectMemory fetchPointer: MethodIndex ofObject: homeContext.
+ 		 (self primitiveIndexOf: theMethod) = 198 ifTrue:
+ 			[^homeContext].
+ 		 ^0].
+ 	ctxtOrNilOrZero = objectMemory nilObject ifFalse:
+ 		[(self findMethodWithPrimitive: 0 FromContext: ctxtOrNilOrZero UpToContext: homeContext)
+ 		  = objectMemory nilObject ifTrue:
+ 			[^objectMemory nilObject]].
- 		 (self primitiveIndexOf: theMethod) == 198 ifTrue:
- 			[^homeContext]].
  	^ctxtOrNilOrZero!