"
 COPYRIGHT (c) 1991 by Claus Gittinger
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"

ByteCodeCompiler subclass:#Decompiler
       instanceVariableNames:'extra hasLineNo bytes literals index '
       classVariableNames:''
       poolDictionaries:''
       category:'System-Compiler'
!

Decompiler comment:'

COPYRIGHT (c) 1991 by Claus Gittinger
             All Rights Reserved

additional methods for decompilation

$Header: /cvs/stx/stx/libcomp/Attic/Decomp.st,v 1.3 1993-10-13 02:41:18 claus Exp $
'!

!Decompiler class methodsFor:'decompiling'!

decompile:aMethod
    ^ (self new) decompile:aMethod

    "Decompiler decompile:(FileBrowser compiledMethodAt:#initialize)"
! !

!Decompiler methodsFor:'decompiling'!

showOffset:byte
    |offs|

    index := index + 1.
    (byte > 127) ifTrue:[
        offs := byte - 256
    ] ifFalse:[
        offs := byte
    ].
    Transcript show:(offs printString).
    Transcript show:' ('.
    Transcript show:(index + offs) printString.
    Transcript show:')'
!

showLongOffset:byte
    |offs|

    index := index + 1.
    (byte > 127) ifTrue:[
        offs := byte - 256 - 128
    ] ifFalse:[
        offs := byte + 128
    ].
    Transcript show:offs printString.
    Transcript show:' ('.
    Transcript show:(index + offs) printString.
    Transcript show:')'
!

showVeryLongOffset:byte
    |offs|

    index := index + 1.
    (byte > 127) ifTrue:[
        offs := byte - 256 - 256
    ] ifFalse:[
        offs := byte + 256
    ].
    Transcript show:offs printString.
    Transcript show:' ('.
    Transcript show:(index + offs) printString.
    Transcript show:')'
!

showAbsOffset:byte
    |offs b2|

    index := index + 1.
    b2 := (bytes at:index).
    offs := byte + (b2 bitShift:8).
    index := index + 1.
    Transcript show:offs printString.
    Transcript show:' ('.
    Transcript show:offs printString.
    Transcript show:')'
!

showAbsOffsetLevel:byte
    |offs b2|

    index := index + 1.
    b2 := (bytes at:index).
    offs := byte + (b2 bitShift:8).
    index := index + 1.
    Transcript show:offs printString.
    Transcript show:' ('.
    Transcript show:offs printString.
    Transcript show:')'.
    self showNvarNargsAt:index.
    index := index + 2
!

showNvarNargsAt:index
    Transcript show:' nv='.
    Transcript show:(bytes at:index) printString.
    Transcript show:' na='.
    Transcript show:(bytes at:(index + 1)) printString
!

showLiteralAt:index
    |offs|

    offs := bytes at:index.
    Transcript show:(literals at:offs) printString
!

showLiteral:byte
    index := index + 1.
    Transcript show:(literals at:byte) printString.
!

showLiteralSkip5:byte
    index := index + 1.
    Transcript show:(literals at:byte) printString.
    index := index + 5
!

showOffsetLevel:byte
    self showOffset:byte.
    self showNvarNargsAt:index.
    index := index + 2
!

showLongOffsetLevel:byte
    self showLongOffset:byte.
    self showNvarNargsAt:index.
    index := index + 2
!

showVeryLongOffsetLevel:byte
    self showVeryLongOffset:byte.
    self showNvarNargsAt:index.
    index := index + 2
!

showSendArgs:byte
    Transcript show:byte printString.
    Transcript show:' '.
    index := index + 1.
    self showLiteralAt:index.
    index := index + 1
!

showSuperSendArgs:byte
    Transcript show:byte printString.
    Transcript show:' '.
    index := index + 1.
    self showLiteralAt:index.
    index := index + 1.
    self showLiteralAt:index.
    index := index + 1
!

showLineNo:byte
    Transcript show:' line:' , byte printString.
    index := index + 1
!

showIndex:byte
    Transcript show:byte printString.
    index := index + 1
!

showIndexLevel:byte
    self showIndex:byte.
    self showNvarNargsAt:index.
    index := index + 2
!

showNumber:byte
    Transcript show:byte printString.
    index := index + 1
!

showPC
    Transcript show:(index printStringRadix:10 size:3 fill:(Character space)).
    Transcript show:': '.
    Transcript show:((bytes at:index) printStringRadix:16 size:2 fill:$0).
    Transcript show:' '.
!

decompile:aMethod
    |nBytes offs byte sym sel|

    aMethod isNil ifTrue:[
        Transcript showCr:'nil method'.
        ^ self
    ].   

    bytes := aMethod byteCode.
    bytes isNil ifTrue:[
        Transcript showCr:'no bytecode'.
        ^ self
    ].
    literals := aMethod literals.
    index := 1.
    nBytes := bytes size.
    [index <= nBytes] whileTrue:[
        self showPC.
        sym := self symbolicCodeFor:(bytes at:index).
        Transcript show:sym.
"
        extra notNil ifTrue:[Transcript show:(extra printString)].
"
        hasLineNo ifTrue:[
            index := index + 1
        ].
        index := index + 1.
        extra notNil ifTrue:[
            Transcript show:' '.
            byte := bytes at:index.

            "compute argument showXXX selector from extra ..."

            sel := 'show' , extra , ':'.
            sel at:5 put:(sel at:5) asUppercase.
            self perform:sel asSymbol with:byte
        ].
        Transcript showCr:''
    ]
!

symbolicCodeFor:aByte
    |syms extras lnos|

    syms := #(  retTop         " 0  "
                retNil
                retTrue
                retFalse
                ret0
                retSelf         " 5  "
                blockRetTop
                nil
                nil
                nil
                pushNil         " 10 "
                pushTrue
                pushFalse
                pushInt
                pushLit
                pushSelf        " 15 "
                pushNum
                pushChar
                drop
                send
                superSend       " 20 "
                send0
                send1
                send2
                send3
                sendDrop        " 25 "
                sendDrop0
                sendDrop1
                sendDrop2
                sendDrop3
                pushMethodArg   " 30 "
                pushMethodVar
                pushBlockArg
                pushBlockVar
                pushInstVar
                pushClassVar    " 35 "
                pushGlobal
                storeMethodVar
                storeBlockVar
                storeInstVar
                storeClassVar   " 40 "
                storeGlobal
                pushOuterBlockArg
                pushOuter1BlockArg
                pushOuter2BlockArg
                equal           " 45 "
                notEqual
                dup
                equal0
                notEqual0
                falseJump       " 50 "
                trueJump
                nilJump
                notNilJump
                jump
                makeBlock       " 55 "
                zeroJump
                notZeroJump
                eqJump
                notEqJump
                falseJump       " 60 "
                trueJump
                nilJump
                notNilJump
                jump
                makeBlock       " 65 "
                zeroJump
                notZeroJump
                eqJump
                notEqJump
                falseJump       " 70 "
                trueJump
                nilJump
                notNilJump
                jump
                makeBlock       " 75 "
                zeroJump
                notZeroJump
                eqJump
                notEqJump
                pushMethodVar1  " 80 "
                pushMethodVar2
                pushMethodVar3
                pushMethodVar4
                pushMethodVar5
                pushMethodVar6  " 85 "
                pushMethodArg1
                pushMethodArg2
                pushMethodArg3
                pushMethodArg4
                pushInstVar1    " 90 "
                pushInstVar2
                pushInstVar3
                pushInstVar4
                pushInstVar5
                pushInstVar6    " 95 "
                pushInstVar7
                pushInstVar8
                pushInstVar9
                pushInstVar10
                storeMethodVar1 " 100 "
                storeMethodVar2
                storeMethodVar3
                storeMethodVar4
                storeMethodVar5
                storeMethodVar6 " 105 "
                sendY
                sendX
                sendWidth
                sendHeight
                storeInstVar1   " 110 "
                storeInstVar2
                storeInstVar3
                storeInstVar4
                storeInstVar5
                storeInstVar6  " 115 "
                storeInstVar7
                storeInstVar8
                storeInstVar9
                storeInstVar10
                push0           " 120 "
                push1
                pushMinus1
                sendPlus1
                sendMinus1
                incMethodVar    " 125 "
                decMethodVar
                retNum
                pushOuterBlockVar
                storeOuterBlockVar
                sendEQ          " 130 "
                sendPLUS
                sendNE
                sendMINUS
                sendCLASS
                sendAT          " 135 "
                sendATPUT
                sendBitAnd
                sendBitOr
                push2
                pushBlockArg1   " 140 "
                pushBlockArg2
                pushBlockArg3
                pushBlockArg4
                pushContext
                sendGT          " 145 "
                sendGE
                sendLT
                sendLE
                sendNEXT
                sendPEEK        " 150 "
                sendVALUE
                sendVALUE1
                sendSIZE
                sendORIGIN
                sendEXTENT      " 155 "
                make0Block             
                makeNILBlock
                nil
                nil
                retMvar1        " 160 "
                retMvar2        
                retMvar3        
                retMvar4        
                retMvar5        
                retMvar6        " 165 "
                retIvar1        
                retIvar2        
                retIvar3        
                retIvar4        
                retIvar5        " 170 "
                retIvar6        
                retIvar7        
                retIvar8        
                retMarg1        
                retMarg2        " 175 "
                pushClassInstVar
                storeClassInstVar
                nil
                nil
                sendSelf0       " 180 "
                sendSelf1
                sendSelf2
                sendSelf3
                sendSelfDrop0   
                sendSelfDrop1   " 185 "
                sendSelfDrop2
                sendSelfDrop3
                nil
                nil
                falseJumpAbs    " 190 "
                trueJumpAbs     
                nilJumpAbs     
                notNilJumpAbs   
                jumpAbs        
                makeBlockAbs    " 195 "
                zeroJumpAbs
                notZeroJumpAbs
                eqJumpAbs
                notEqJumpAbs    " 199 "
              ).

    lnos := #(  false          " 0  "
                false   
                false   
                false   
                false
                false          " 5  "
                false
                false
                false
                false
                false          " 10 "
                false
                false
                false
                false
                false          " 15 "
                false
                false
                false
                true
                true           " 20 "
                true 
                true 
                true 
                true 
                true           " 25 "
                true 
                true 
                true 
                true 
                false          " 30 "
                false
                false
                false
                false
                false          " 35 "
                false
                false
                false
                false
                false           " 40 "
                false
                false
                false
                false
                false           " 45 "
                false
                false
                false
                false
                false       " 50 "
                false
                false
                false
                false
                false       " 55 "
                false
                false
                false
                false
                false       " 60 "
                false
                false
                false
                false
                false       " 65 "
                false
                false
                false
                false
                false       " 70 "
                false
                false
                false
                false
                false       " 75 "
                false
                false
                false
                false 
                false  " 80 "
                false
                false
                false
                false
                false  " 85 "
                false
                false
                false
                false
                false    " 90 "
                false
                false
                false
                false
                false    " 95 "
                false
                false
                false
                false
                false " 100 "
                false
                false
                false
                false
                false " 105 "
                false
                false
                false
                false
                false   " 110 "
                false
                false
                false
                false
                false  " 115 "
                false
                false
                false
                false
                false           " 120 "
                false
                false
                false
                false
                false    " 125 "
                false
                false
                false
                false
                false          " 130 "
                false
                false
                false
                false
                false          " 135 "
                false
                false
                false
                false
                false   " 140 "
                false
                false
                false
                false
                false          " 145 "
                false
                false
                false
                false
                false        " 150 "
                false
                false
                false
                false
                false             " 155 "
                false
                false
                false
                false
                false        " 160 "
                false
                false
                false
                false
                false        " 165 "
                false
                false
                false
                false
                false        " 170 "
                false
                false
                false
                false
                false        " 175 "
                false
                false
                false
                false
                true         " 180 "
                true
                true
                true
                true
                true         " 185 "
                true
                true
                false
                false
                false         " 190 "
                false
                false
                false
                false
                false         " 195 "
                false
                false
                false
                false         " 199 "
              ).

    extras := #(nil             " 0  "
                nil
                nil
                nil
                nil
                nil             " 5  "
                nil
                nil
                nil
                nil
                nil             " 10 "
                nil
                nil
                nil
                literal
                nil             " 15 "
                number
                nil
                nil
                sendArgs
                superSendArgs   " 20 "
                literal
                literal
                literal
                literal
                sendArgs        " 25 "
                literal
                literal
                literal
                literal
                index           " 30 "
                index
                index
                index
                index
                literalSkip5    " 35 "
                literalSkip5
                index
                index
                index
                literalSkip5    " 40 "
                literalSkip5
                indexLevel
                index
                index
                nil             " 45 "
                nil
                nil
                nil
                nil
                offset          " 50 "
                offset
                offset
                offset
                offset
                offsetLevel     " 55 "
                offset
                offset
                offset
                offset
                longOffset      " 60 "
                longOffset
                longOffset
                longOffset
                longOffset
                longOffsetLevel " 65 "
                longOffset
                longOffset
                longOffset
                longOffset
                veryLongOffset  " 70 "
                veryLongOffset
                veryLongOffset
                veryLongOffset
                veryLongOffset
                veryLongOffsetLevel  " 75 "
                veryLongOffset
                veryLongOffset
                veryLongOffset
                veryLongOffset
                nil             " 80 "
                nil
                nil
                nil
                nil
                nil             " 85 "
                nil
                nil
                nil
                nil
                nil             " 90 "
                nil
                nil
                nil
                nil
                nil             " 95 "
                nil
                nil
                nil
                nil
                nil             " 100 "
                nil
                nil
                nil
                nil
                nil             " 105 "
                nil
                nil
                nil
                nil
                nil             " 110 "
                nil
                nil
                nil
                nil
                nil             " 115 "
                nil
                nil
                nil
                nil
                nil             " 120 "
                nil
                nil
                nil
                nil
                index           " 125 "
                index
                number
                indexLevel
                indexLevel
                nil             " 130 "
                nil
                nil
                nil
                nil
                nil             " 135 "
                nil
                nil
                nil
                nil
                nil             " 140 "
                nil
                nil
                nil
                nil
                nil             " 145 "
                nil
                nil
                nil
                nil
                nil             " 150 "
                nil
                nil
                nil
                nil
                nil             " 155 "
                nil
                nil
                nil
                nil
                nil             " 160 "
                nil
                nil
                nil
                nil
                nil             " 165 "
                nil
                nil
                nil
                nil
                nil             " 170 "
                nil
                nil
                nil
                nil
                nil             " 175 "
                index
                index
                nil
                nil
                literal         " 180 "
                literal
                literal
                literal
                literal         
                literal         " 185 "
                literal
                literal
                nil
                nil
                absOffset       " 190 "
                absOffset
                absOffset
                absOffset
                absOffset
                absOffsetLevel
                absOffset
                absOffset
                absOffset
                absOffset       " 199 "
             ).

    extra := extras at:(aByte + 1).
    hasLineNo := lnos at:(aByte + 1).
    ^ syms at:(aByte + 1)
! !