Eliot Miranda uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscogSPC-eem.2131.mcz

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

Name: VMMaker.oscogSPC-eem.2131 Author: eem Time: 17 February 2017, 9:44:55.365762 am UUID: 8f61c300-0034-45a8-85d9-7b0bd4ee199d Ancestors: VMMaker.oscogSPC-eem.2130

Fix assert fails in Spur due to failing perform primitives not restoring the function pointer and argumentCount correctly.

=============== Diff against VMMaker.oscogSPC-eem.2130 ===============

Item was changed: ----- Method: StackInterpreter>>primitiveObject:perform:withArguments:lookedUpIn: (in category 'control primitives') ----- primitiveObject: actualReceiver perform: selector withArguments: argumentArray lookedUpIn: lookupClassOrNil "Common routine used by perform:withArgs:, perform:withArgs:inSuperclass:, object:perform:withArgs:inClass: et al. Answer nil on success.

NOTE: The case of doesNotUnderstand: is not a failure to perform. The only failures are arg types and consistency of argumentCount.

Since we're in the stack VM we can assume there is space to push the arguments provided they are within limits (max argument count is 15). We can therefore deal with the arbitrary amount of state to remove from the stack (lookup class, selector, mirror receiver) and arbitrary argument orders by deferring popping anything until we know whether the send has succeeded. So on failure we merely have to remove the actual receiver and arguments pushed, and on success we have to slide the actual receiver and arguments down to replace the original ones." <inline: true> | arraySize performArgCount delta | (objectMemory isArray: argumentArray) ifFalse: [^self primitiveFailFor: PrimErrBadArgument].

"Check if number of arguments is reasonable; MaxNumArgs isn't available so just use LargeContextSize" arraySize := objectMemory numSlotsOf: argumentArray. arraySize > (LargeContextSlots - CtxtTempFrameStart) ifTrue: [^self primitiveFailFor: PrimErrBadNumArgs].

performArgCount := argumentCount. "Push newMethod to save it in case of failure, then push the actual receiver and the args in the array." self push: newMethod. self push: actualReceiver. "Copy the arguments to the stack, in case of MNU, and lookup" 1 to: arraySize do: [:index| self push: (objectMemory fetchPointer: index - 1 ofObject: argumentArray)]. argumentCount := arraySize. messageSelector := selector. self sendBreakpoint: messageSelector receiver: actualReceiver. self printSends ifTrue: [self printActivationNameForSelector: messageSelector startClass: (lookupClassOrNil isNil ifTrue: [objectMemory fetchClassOf: actualReceiver] ifFalse: [lookupClassOrNil]); cr]. self findNewMethodInClassTag: (lookupClassOrNil isNil ifTrue: [objectMemory fetchClassTagOf: actualReceiver] ifFalse: [objectMemory classTagForClass: lookupClassOrNil]).

"Only test CompiledMethods for argument count - any other objects playacting as CMs will have to take their chances" ((objectMemory isOopCompiledMethod: newMethod) and: [(self argumentCountOf: newMethod) ~= argumentCount]) ifTrue: ["Restore the state by popping the array entries, the actual receiver and the saved newMethod, leaving the selector and array, and fail. N.B. If an MNU has happened then argumentCount will match newMethod, so this code will not be reached." "These asserts check that an MNU has not occurred if the argumentCount doesn't match the newMethod." self assert: (self stackTop = (arraySize = 0 ifTrue: [actualReceiver] ifFalse: [(objectMemory fetchPointer: arraySize - 1 ofObject: argumentArray)])). self assert: argumentCount = arraySize. self pop: arraySize + 1. newMethod := self popStack. + "Must reset primitiveFunctionPointer for checkForAndFollowForwardedPrimitiveState" + objectMemory hasSpurMemoryManagerAPI ifTrue: + [argumentCount := performArgCount. + primitiveFunctionPointer := lookupClassOrNil + ifNil: [#primitivePerformWithArgs] + ifNotNil: [#primitivePerformInSuperclass]]. ^self primitiveFailFor: PrimErrBadNumArgs].

"Cannot fail this primitive from here-on. Slide the actual receiver and arguments down to replace the perform arguments and saved newMethod and then execute the new method. Use argumentCount not arraySize because an MNU may have changed it." delta := objectMemory wordSize * (performArgCount + 2). "+2 = receiver + saved newMethod" argumentCount * objectMemory wordSize to: 0 by: objectMemory wordSize negated do: [:offset| stackPages longAt: stackPointer + offset + delta put: (stackPages longAt: stackPointer + offset)]. self pop: performArgCount + 2. self executeNewMethod. self initPrimCall. "Recursive xeq affects primErrorCode" ^nil!

Item was changed: ----- Method: StackInterpreterPrimitives>>primitivePerform (in category 'control primitives') ----- primitivePerform <returnTypeC: #void> | newReceiver lookupClassTag performMethod | performMethod := newMethod. messageSelector := self stackValue: argumentCount - 1. newReceiver := self stackValue: argumentCount.

"NOTE: the following lookup may fail and be converted to #doesNotUnderstand:, so we must adjust argumentCount and slide args now, so that will work."

"Slide arguments down over selector" argumentCount := argumentCount - 1. argumentCount to: 1 by: -1 do: [:i| stackPages longAt: stackPointer + (i * objectMemory wordSize) put: (stackPages longAt: stackPointer + ((i - 1) * objectMemory wordSize))]. self pop: 1. lookupClassTag := objectMemory fetchClassTagOf: newReceiver. self sendBreakpoint: messageSelector receiver: newReceiver. self printSends ifTrue: [self printActivationNameForSelector: messageSelector startClass: (objectMemory classForClassTag: lookupClassTag); cr]. self findNewMethodInClassTag: lookupClassTag.

"Only test CompiledMethods for argument count - other objects will have to take their chances" ((objectMemory isOopCompiledMethod: newMethod) and: [(self argumentCountOf: newMethod) = argumentCount]) ifFalse: ["Slide the args back up (sigh) and re-insert the selector." self unPop: 1. 1 to: argumentCount by: 1 do: [:i | stackPages longAt: stackPointer + ((i - 1) * objectMemory wordSize) put: (stackPages longAt: stackPointer + (i * objectMemory wordSize))]. stackPages longAt: stackPointer + (argumentCount * objectMemory wordSize) put: messageSelector. argumentCount := argumentCount + 1. newMethod := performMethod. + "Must reset primitiveFunctionPointer for checkForAndFollowForwardedPrimitiveState" + objectMemory hasSpurMemoryManagerAPI ifTrue: + [primitiveFunctionPointer := #primitivePerform]. + ^self primitiveFailFor: PrimErrBadNumArgs]. - ^self primitiveFail].

self executeNewMethod. "Recursive xeq affects primErrorCode" self initPrimCall!