Eliot Miranda uploaded a new version of Compiler to project The Trunk: http://source.squeak.org/trunk/Compiler-eem.372.mcz
==================== Summary ====================
Name: Compiler-eem.372 Author: eem Time: 11 January 2018, 9:30:54.229387 am UUID: 692e5c85-e068-42df-9404-266f9bd3c93f Ancestors: Compiler-eem.371
Move BlockLocalTempCounter to Kernel. It is used to implement BlockClosure>>numTemps, which is used more broadly than simply the decompiler and debugger.
=============== Diff against Compiler-eem.371 ===============
Item was removed: - InstructionClient subclass: #BlockLocalTempCounter - instanceVariableNames: 'stackPointer scanner blockEnd joinOffsets' - classVariableNames: '' - poolDictionaries: '' - category: 'Compiler-Support'! - - !BlockLocalTempCounter commentStamp: 'eem 1/11/2018 08:30' prior: 0! - I am a support class for the decompiler that is used to find the number of local temps in a block by finding out what the stack offset is at the end of a block. I am necessary because in the EncoderForV3PlusClosures bytecode set the only way to initialize block-local temporaries is with pushConstant: nil bytecodes, but such bytecodes are ambiguous with a pushConstant: nil used to pass nil as a parameter or answer it as a result. By scanning through to the end of the block these can be disambiguated by tracking the stack depth.!
Item was removed: - ----- Method: BlockLocalTempCounter class>>tempCountForBlockAt:in: (in category 'instance creation') ----- - tempCountForBlockAt: pc in: method - ^self new tempCountForBlockAt: pc in: method!
Item was removed: - ----- Method: BlockLocalTempCounter class>>tempCountForBlockStartingAt:in: (in category 'instance creation') ----- - tempCountForBlockStartingAt: startpc in: method - ^self new - tempCountForBlockAt: (method encoderClass pcOfBlockCreationBytecodeForBlockStartingAt: startpc in: method) - in: method!
Item was removed: - ----- Method: BlockLocalTempCounter>>blockReturnConstant: (in category 'instruction decoding') ----- - blockReturnConstant: value - "Return Constant From Block bytecode." - scanner pc < blockEnd ifTrue: - [self doJoin]!
Item was removed: - ----- Method: BlockLocalTempCounter>>blockReturnTop (in category 'instruction decoding') ----- - blockReturnTop - "Return Top Of Stack bytecode." - stackPointer := stackPointer - 1. - scanner pc < blockEnd ifTrue: - [self doJoin]!
Item was removed: - ----- Method: BlockLocalTempCounter>>directedSuperSend:numArgs: (in category 'instruction decoding') ----- - directedSuperSend: selector numArgs: numArgs - "Send Message Above Specific Class With Selector, selector, bytecode. - Start the lookup above the class that is the value of the association on - top of stack. The arguments of the message are found in the top numArgs - stack locations beneath the association, and the receiver just below them." - - stackPointer := stackPointer - (numArgs + 1)!
Item was removed: - ----- Method: BlockLocalTempCounter>>doDup (in category 'instruction decoding') ----- - doDup - "Duplicate Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>doJoin (in category 'private') ----- - doJoin - scanner pc < blockEnd ifTrue: - [stackPointer := joinOffsets at: scanner pc ifAbsent: [scanner followingPc]] - - "the ifAbsent: handles a caseOf:otherwise: where all cases return, which results - in the branch around the otherwise being unreached. e.g. in the following - jumpTo: L2 - is unreached. - - | t | - t caseOf: { [nil] -> [^thisContext method abstractSymbolic] } - otherwise: ['Oh no Mr Bill!!'] - - pushTemp: 0 - pushConstant: nil - send: #= (1 arg) - jumpFalseTo: L1 - pushThisContext: - send: #method (0 args) - send: #abstractSymbolic (0 args) - returnTop - jumpTo: L2 - L1: - pushConstant: 'Oh no Mr Bill!!' - L2: - returnTop"!
Item was removed: - ----- Method: BlockLocalTempCounter>>doPop (in category 'instruction decoding') ----- - doPop - "Remove Top Of Stack bytecode." - stackPointer := stackPointer - 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>jump: (in category 'instruction decoding') ----- - jump: offset - "Unconditional Jump bytecode." - offset > 0 ifTrue: - [joinOffsets at: scanner pc + offset put: stackPointer. - self doJoin]!
Item was removed: - ----- Method: BlockLocalTempCounter>>jump:if: (in category 'instruction decoding') ----- - jump: offset if: condition - "Conditional Jump bytecode." - stackPointer := stackPointer - 1. - offset > 0 ifTrue: - [joinOffsets at: scanner pc + offset put: stackPointer]!
Item was removed: - ----- Method: BlockLocalTempCounter>>methodReturnConstant: (in category 'instruction decoding') ----- - methodReturnConstant: value - "Return Constant bytecode." - self doJoin!
Item was removed: - ----- Method: BlockLocalTempCounter>>methodReturnReceiver (in category 'instruction decoding') ----- - methodReturnReceiver - "Return Self bytecode." - self doJoin!
Item was removed: - ----- Method: BlockLocalTempCounter>>methodReturnTop (in category 'instruction decoding') ----- - methodReturnTop - "Return Top Of Stack bytecode." - stackPointer := stackPointer - 1. - self doJoin!
Item was removed: - ----- Method: BlockLocalTempCounter>>popIntoLiteralVariable: (in category 'instruction decoding') ----- - popIntoLiteralVariable: anAssociation - "Remove Top Of Stack And Store Into Literal Variable bytecode." - stackPointer := stackPointer - 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>popIntoReceiverVariable: (in category 'instruction decoding') ----- - popIntoReceiverVariable: offset - "Remove Top Of Stack And Store Into Instance Variable bytecode." - stackPointer := stackPointer - 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>popIntoRemoteTemp:inVectorAt: (in category 'instruction decoding') ----- - popIntoRemoteTemp: remoteTempIndex inVectorAt: tempVectorIndex - "Remove Top Of Stack And Store Into Offset of Temp Vector bytecode." - stackPointer := stackPointer - 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>popIntoTemporaryVariable: (in category 'instruction decoding') ----- - popIntoTemporaryVariable: offset - "Remove Top Of Stack And Store Into Temporary Variable bytecode." - stackPointer := stackPointer - 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushActiveContext (in category 'instruction decoding') ----- - pushActiveContext - "Push Active Context On Top Of Its Own Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushClosureCopyNumCopiedValues:numArgs:blockSize: (in category 'instruction decoding') ----- - pushClosureCopyNumCopiedValues: numCopied numArgs: numArgs blockSize: blockSize - "Push Closure bytecode. Either compute the end of the block if this is - the block we're analysing, or skip it, adjusting the stack as appropriate." - blockEnd - ifNil: [blockEnd := scanner pc + blockSize] - ifNotNil: - [stackPointer := stackPointer - numCopied + 1. - scanner pc: scanner pc + blockSize]!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushConsArrayWithElements: (in category 'instruction decoding') ----- - pushConsArrayWithElements: numElements - "Push Cons Array of size numElements popping numElements items from the stack into the array bytecode." - stackPointer := stackPointer - numElements + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushConstant: (in category 'instruction decoding') ----- - pushConstant: value - "Push Constant, value, on Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushLiteralVariable: (in category 'instruction decoding') ----- - pushLiteralVariable: anAssociation - "Push Contents Of anAssociation On Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushNewArrayOfSize: (in category 'instruction decoding') ----- - pushNewArrayOfSize: numElements - "Push New Array of size numElements bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushReceiver (in category 'instruction decoding') ----- - pushReceiver - "Push Active Context's Receiver on Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushReceiverVariable: (in category 'instruction decoding') ----- - pushReceiverVariable: offset - "Push Contents Of the Receiver's Instance Variable Whose Index - is the argument, offset, On Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushRemoteTemp:inVectorAt: (in category 'instruction decoding') ----- - pushRemoteTemp: remoteTempIndex inVectorAt: tempVectorIndex - "Push Contents at Offset in Temp Vector bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>pushTemporaryVariable: (in category 'instruction decoding') ----- - pushTemporaryVariable: offset - "Push Contents Of Temporary Variable Whose Index Is the - argument, offset, On Top Of Stack bytecode." - stackPointer := stackPointer + 1!
Item was removed: - ----- Method: BlockLocalTempCounter>>send:super:numArgs: (in category 'instruction decoding') ----- - send: selector super: supered numArgs: numberArguments - "Send Message With Selector, selector, bytecode. The argument, - supered, indicates whether the receiver of the message is specified with - 'super' in the source method. The arguments of the message are found in - the top numArguments locations on the stack and the receiver just - below them." - - stackPointer := stackPointer - numberArguments!
Item was removed: - ----- Method: BlockLocalTempCounter>>tempCountForBlockAt:in: (in category 'initialize-release') ----- - tempCountForBlockAt: pc in: method - "Compute the number of local temporaries in a block. - If the block begins with a sequence of push: nil bytecodes then some of - These could be initializing local temps. We can only reliably disambuguate - them from other uses of nil by parsing the stack and seeing what the offset - of the stack pointer is at the end of the block. - - There are short-cuts. The ones we take here are - - if there is no sequence of push nils there can be no local temps - - we follow forward jumps to shorten the amount of scanning" - stackPointer := 0. - scanner := InstructionStream new method: method pc: pc. - scanner interpretNextInstructionFor: self. - blockEnd ifNil: - [self error: 'pc is not that of a block']. - scanner nextByte = method encoderClass pushNilCode ifTrue: - [joinOffsets := Dictionary new. - [scanner pc < blockEnd] whileTrue: - [scanner interpretNextInstructionFor: self]]. - ^stackPointer!
Item was removed: - ----- Method: BlockLocalTempCounter>>testTempCountForBlockAt:in: (in category 'initialize-release') ----- - testTempCountForBlockAt: startPc in: method - "Compute the number of local temporaries in a block. - If the block begins with a sequence of push: nil bytecodes then some of - These could be initializing local temps. We can only reliably disambuguate - them from other uses of nil by parsing the stack and seeing what the offset - of the stack pointer is at the end of the block.There are short-cuts. The only - one we take here is - - if there is no sequence of push nils there can be no local temps" - - | symbolicLines line prior thePc | - symbolicLines := Dictionary new. - method symbolicLinesDo: - [:pc :lineForPC| symbolicLines at: pc put: lineForPC]. - stackPointer := 0. - scanner := InstructionStream new method: method pc: startPc. - scanner interpretNextInstructionFor: self. - blockEnd ifNil: - [self error: 'pc is not that of a block']. - scanner nextByte = method encoderClass pushNilCode ifTrue: - [joinOffsets := Dictionary new. - [scanner pc < blockEnd] whileTrue: - [line := symbolicLines at: scanner pc. - prior := stackPointer. - thePc := scanner pc. - scanner interpretNextInstructionFor: self. - Transcript cr; print: prior; nextPutAll: '->'; print: stackPointer; tab; print: thePc; tab; nextPutAll: line; flush]]. - ^stackPointer!
Item was removed: - ----- Method: CompiledBlock>>startpcsToBlockExtents (in category '*Compiler-support') ----- - startpcsToBlockExtents - ^self outerCode startpcsToBlockExtents!
Item was removed: - ----- Method: CompiledMethod>>blockExtentsInto:from:to:scanner:numberer: (in category '*Compiler-support') ----- - blockExtentsInto: aDictionary from: initialPC to: endPC scanner: scanner numberer: numbererBlock - "Support routine for startpcsToBlockExtents" - | extentStart blockSizeOrLocator | - extentStart := numbererBlock value. - [scanner pc <= endPC] whileTrue: - [blockSizeOrLocator := scanner interpretNextInstructionFor: BlockStartLocator new. - blockSizeOrLocator isInteger ifTrue: - [self - blockExtentsInto: aDictionary - from: scanner pc - to: scanner pc + blockSizeOrLocator - 1 - scanner: scanner - numberer: numbererBlock]]. - aDictionary at: initialPC put: (extentStart to: numbererBlock value). - ^aDictionary!
Item was removed: - ----- Method: CompiledMethod>>startpcsToBlockExtents (in category '*Compiler-support') ----- - startpcsToBlockExtents - "Answer a Dictionary of startpc to Interval of blockExtent, using the - identical numbering scheme described in and orchestrated by - BlockNode>>analyseArguments:temporaries:rootNode:. This is used - to find the temp names for any block in a method, as needed by the - decompiler and debugger. By indirecting through the blockExtent - instead of using the startpc directly we decouple access to temp - names from the exact bytecode; insulating the decompiler and - debugger from minor changes in the compiler's output. If the - recompilation doesn't produce exactly the same bytecode at exactly - the same offset no matter; the blockExtents will be the same." - | index | - index := 0. - ^self - blockExtentsInto: Dictionary new - from: self initialPC - to: self endPC - scanner: (InstructionStream on: self) - numberer: [| value | value := index. index := index + 2. value]!