Eliot Miranda uploaded a new version of Compiler to project The Trunk:
http://source.squeak.org/trunk/Compiler-eem.308.mcz

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

Name: Compiler-eem.308
Author: eem
Time: 16 September 2015, 11:42:08.344 am
UUID: 0420593e-81fc-463c-8d0d-5a0cc7de2845
Ancestors: Compiler-eem.307

Addition:
Scanner>>typedScan:do:, useful for tools (watch this space).

Optimisation:
Avoid an expensive visit of the parse tree if there are no temps when checking if they need nilling before being read.

Polish:
Better error message with bindTemp:.

Decompile empty blocks as [] not [nil].

Nuke obsolete method creation methods generateMethodOfClass:trailer:from:.

=============== Diff against Compiler-eem.307 ===============

Item was changed:
  ----- Method: BlockNode>>nilReadBeforeWrittenTemps (in category 'code generation (closures)') -----
  nilReadBeforeWrittenTemps
  	| visitor readBeforeWritten |
+ 	temporaries isEmpty ifTrue:
+ 		[^self].
  	self accept: (visitor := OptimizedBlockLocalTempReadBeforeWrittenVisitor new).
  	readBeforeWritten := visitor readBeforeWritten.
  	temporaries reverseDo:
  		[:temp|
  		((readBeforeWritten includes: temp)
  		 and: [temp isRemote not]) ifTrue:
  			[statements addFirst: (AssignmentNode new variable: temp value: NodeNil)]]!

Item was changed:
  ----- Method: BytecodeEncoder class>>extensionsFor:in:into: (in category 'instruction stream support') -----
  extensionsFor: pc in: aCompiledMethod into: trinaryBlock
  	"If the bytecode at pc is an extension, or if the bytecode at pc is preceeded by extensions,
  	 then evaluate aTrinaryBlock with the values of extA and extB and number of extension *bytes*.
  	 If the bytecode at pc is neither an extension or extended then evaluate with 0, 0, 0."
+  
+ 	| prevPC |
+ 	"If there is what appears to be an extension bytecode before this bytecode
+ 	 then scan for the previous pc to confirm."
+ 	(pc - 2 >= aCompiledMethod initialPC
+ 	 and: [self isExtension: (aCompiledMethod at: pc - 2)]) ifTrue:
+ 		[prevPC := aCompiledMethod pcPreviousTo: pc.
+ 		 (self nonExtensionPcAt: prevPC in: aCompiledMethod) = pc ifTrue:
+ 			[^self extensionsAt: prevPC in: aCompiledMethod into: trinaryBlock]].
+ 	^self extensionsAt: pc in: aCompiledMethod into: trinaryBlock!
- 
- 	self subclassResponsibility!

Item was added:
+ ----- Method: BytecodeEncoder class>>nonExtensionPcAt:in: (in category 'instruction stream support') -----
+ nonExtensionPcAt: pc in: method
+ 	"Answer the pc of the actual bytecode at pc in method, skipping past any preceeding extensions."
+ 	| thePC bytecode |
+ 	thePC := pc.
+ 	[self isExtension: (bytecode := method at: thePC)] whileTrue:
+ 		[thePC := thePC + (self bytecodeSize: bytecode)].
+ 	^thePC!

Item was removed:
- ----- Method: BytecodeEncoder>>generateMethodOfClass:trailer:from: (in category 'method generation') -----
- generateMethodOfClass: aCompiledMethodClass trailer: trailer from: methodNode
- 	"methodNode is the root of a parse tree. Answer an instance of aCompiledMethodClass
- 	 in the receiver's bytecode set and using the receiver's method header format.
- 	 The argument, trailer, is arbitrary but is typically either the reference to the source code
- 	 that is stored with every CompiledMethod, or an encoding of the method's temporary names."
- 
- 	self subclassResponsibility!

Item was changed:
  ----- Method: Decompiler>>blockTo: (in category 'control') -----
  blockTo: end
  	"Decompile a range of code as in statementsTo:, but return a block node."
+ 	| exprs block oldBase lastStatementOfBlockIsNil |
- 	| exprs block oldBase |
  	oldBase := blockStackBase.
  	blockStackBase := stack size.
  	exprs := self statementsTo: end.
+ 	lastStatementOfBlockIsNil := pc < method endPC and: [exprs notEmpty and: [exprs last == (constTable at: 4)]].
+ 	lastStatementOfBlockIsNil ifTrue:
+ 		[exprs := exprs allButLast].
  	block := constructor codeBlock: exprs returns: lastReturnPc = lastPc.
  	blockStackBase := oldBase.
  	lastReturnPc := -1.  "So as not to mislead outer calls"
  	^block!

Item was changed:
  ----- Method: Encoder>>bindTemp: (in category 'temps') -----
  bindTemp: name 
  	"Declare a temporary; error not if a field or class variable."
  	scopeTable at: name ifPresent:[:node|
  		"When non-interactive raise the error only if its a duplicate"
+ 		node isTemp
+ 			ifTrue:[^self notify:'Name already used in this method']
- 		(node isTemp)
- 			ifTrue:[^self notify:'Name is already defined']
  			ifFalse:[self warnAboutShadowed: name]].
  	^self reallyBind: name!

Item was removed:
- ----- Method: EncoderForV3>>generateMethodOfClass:trailer:from: (in category 'method generation') -----
- generateMethodOfClass: aCompiledMethodClass trailer: trailer from: methodNode
- 	"The receiver is the root of a parse tree. Answer an instance of aCompiledMethodClass.
- 	 The argument, trailer, is arbitrary but is typically either the reference to the source code
- 	 that is stored with every CompiledMethod, or an encoding of the method's temporary names."
- 
- 	| primErrNode blkSize nLits literals header method stack |
- 	primErrNode := methodNode primitiveErrorVariableName ifNotNil:
- 						[self fixTemp: methodNode primitiveErrorVariableName].
- 	blkSize := (methodNode block sizeCodeForEvaluatedValue: self)
- 				+ (primErrNode
- 					ifNil: [0]
- 					ifNotNil: [primErrNode sizeCodeForStore: self "The VM relies on storeIntoTemp: (129)"]).
- 	header := self computeMethodHeaderForNumArgs: methodNode arguments size
- 					numTemps: self maxTemp
- 					numLits: (nLits := (literals := self allLiterals) size)
- 					primitive: methodNode primitive.
- 	method := trailer
- 					createMethod: blkSize
- 					class: aCompiledMethodClass
- 					header: header.
- 	1 to: nLits do: [:lit | method literalAt: lit put: (literals at: lit)].
- 	self streamToMethod: method.
- 	stack := ParseStack new init.
- 	primErrNode ifNotNil: [primErrNode emitCodeForStore: stack encoder: self].
- 	stack position: method numTemps.
- 	[methodNode block emitCodeForEvaluatedValue: stack encoder: self]
- 		on: Error "If an attempt is made to write too much code the method will be asked"
- 		do: [:ex|  "to grow, and the grow attempt will fail in CompiledMethod class>>#new:"
- 			ex signalerContext sender method = (CompiledMethod class>>#new:)
- 				ifTrue: [^self error: 'Compiler code size discrepancy']
- 				ifFalse: [ex pass]].
- 	stack position ~= (method numTemps + 1) ifTrue:
- 		[^self error: 'Compiler stack discrepancy'].
- 	self methodStreamPosition ~= (method size - trailer size) ifTrue:
- 		[^self error: 'Compiler code size discrepancy'].
- 	method needsFrameSize: stack size - method numTemps.
- 	^method!

Item was removed:
- ----- Method: EncoderForV3PlusClosures>>generateMethodOfClass:trailer:from: (in category 'method generation') -----
- generateMethodOfClass: aCompiledMethodClass trailer: trailer from: methodNode
- 	"The receiver is the root of a parse tree. Answer an instance of aCompiledMethodClass.
- 	 The argument, trailer, is arbitrary but is typically either the reference to the source code
- 	 that is stored with every CompiledMethod, or an encoding of the method's temporary names."
- 
- 	| primErrNode blkSize nLits locals literals header method stack |
- 	primErrNode := methodNode primitiveErrorVariableName ifNotNil:
- 						[self fixTemp: methodNode primitiveErrorVariableName].
- 	methodNode ensureClosureAnalysisDone.
- 	self rootNode: methodNode. "this is for BlockNode>>sizeCodeForClosureValue:"
- 	blkSize := (methodNode block sizeCodeForEvaluatedValue: self)
- 				+ (primErrNode
- 					ifNil: [0]
- 					ifNotNil:
- 						[primErrNode
- 							index: methodNode arguments size + methodNode temporaries size;
- 							sizeCodeForStore: self "The VM relies on storeIntoTemp: (129)"]).
- 	locals := methodNode arguments, methodNode temporaries, (primErrNode ifNil: [#()] ifNotNil: [{primErrNode}]).
- 	self noteBlockExtent: methodNode block blockExtent hasLocals: locals.
- 	header := self computeMethodHeaderForNumArgs: methodNode arguments size
- 					numTemps: locals size
- 					numLits: (nLits := (literals := self allLiterals) size)
- 					primitive: methodNode primitive.
- 	method := trailer
- 					createMethod: blkSize
- 					class: aCompiledMethodClass
- 					header: header.
- 	1 to: nLits do: [:lit | method literalAt: lit put: (literals at: lit)].
- 	self streamToMethod: method.
- 	stack := ParseStack new init.
- 	primErrNode ifNotNil: [primErrNode emitCodeForStore: stack encoder: self].
- 	stack position: method numTemps.
- 	[methodNode block emitCodeForEvaluatedValue: stack encoder: self]
- 		on: Error "If an attempt is made to write too much code the method will be asked"
- 		do: [:ex|  "to grow, and the grow attempt will fail in CompiledMethod class>>#new:"
- 			ex signalerContext sender method = (CompiledMethod class>>#new:)
- 				ifTrue: [^self error: 'Compiler code size discrepancy']
- 				ifFalse: [ex pass]].
- 	stack position ~= (method numTemps + 1) ifTrue:
- 		[^self error: 'Compiler stack discrepancy'].
- 	self methodStreamPosition ~= (method size - trailer size) ifTrue:
- 		[^self error: 'Compiler code size discrepancy'].
- 	method needsFrameSize: stack size - method numTemps.
- 	^method!

Item was added:
+ ----- Method: Scanner>>typedScan:do: (in category 'public access') -----
+ typedScan: textOrString do: aBinaryBlock
+ 	"Evaluate aBinaryBlock with the token and its type for the first token in input,
+ 	 mapping literals to type #literal and anything else to type #word."
+ 	| theTokensType atNumber theToken |
+ 	self initScannerForTokenization.
+ 	self scan: (ReadStream on: textOrString asString).
+ 	atNumber := hereChar notNil and: [hereChar isDigit].
+ 	theTokensType := tokenType.
+ 	theToken := self advance.
+ 	(theToken == #- and: [atNumber and: [token isNumber]]) ifTrue:
+ 		[theToken := self advance negated].
+ 	theToken isNumber ifTrue: [theTokensType := #number].
+ 	^aBinaryBlock
+ 		value: theToken
+ 		value: ((#(number string literal) includes: theTokensType)
+ 				ifTrue: [#literal]
+ 				ifFalse: [#word])!