"
 COPYRIGHT (c) 1994 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.
"

PrimaryNode subclass:#VariableNode
       instanceVariableNames:'name token selfValue selfClass index block'
       classVariableNames:''
       poolDictionaries:''
       category:'System-Compiler-Support'
!

VariableNode comment:'
COPYRIGHT (c) 1994 by Claus Gittinger
             All Rights Reserved
'!

!VariableNode class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 1994 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.
"
!

version
"
$Header: /cvs/stx/stx/libcomp/VariableNode.st,v 1.2 1994-06-02 20:26:27 claus Exp $
"
!

documentation
"
    node for parse-trees, representing variables
"
! !

!VariableNode class methodsFor:'instance creation'!

type:t token:tok
    ^ (self basicNew) type:t token:tok
!

type:t name:n
    ^ (self basicNew) type:t name:n
!

type:t index:i selfValue:s
    ^ (self basicNew) type:t index:i selfValue:s
!

type:t name:n value:val
    ^ (self basicNew) type:t name:n value:val
!

type:t name:n token:tok index:i
    ^ (self basicNew) type:t name:n token:tok index:i
!

type:t name:n index:i selfValue:s
    ^ (self basicNew) type:t name:n index:i selfValue:s
!

type:t name:n index:i selfClass:s
    ^ (self basicNew) type:t name:n index:i selfClass:s
!

type:t name:n token:tok index:i block:b
    ^ (self basicNew) type:t name:n token:tok index:i block:b
!

type:t token:tok index:i
    ^ (self basicNew) type:t token:tok index:i
!

type:t token:tok index:i block:b
    ^ (self basicNew) type:t token:tok index:i block:b
! !

!VariableNode methodsFor:'accessing'!

type:t token:tok
    type := t.
    token := tok
!

type:t token:tok index:i
    type := t.
    index := i.
    token := tok
!

type:t token:tok index:i block:b
    type := t.
    index := i.
    block := b.
    token := tok
!

type:t name:n
    type := t.
    value := nil.
    name := n
!

type:t index:i selfValue:s
    type := t.
    value := nil.
    index := i.
    selfValue := s
!

type:t name:n value:val
    type := t.
    name := n.
    value := val
!

type:t name:n index:i selfValue:s
    type := t.
    value := nil.
    index := i.
    selfValue := s.
    name := n
!

type:t name:n index:i selfClass:s
    type := t.
    value := nil.
    index := i.
    selfClass := s.
    name := n
!

type:t name:n token:tok index:i
    type := t.
    index := i.
    token := tok.
    name := n
!

type:t name:n token:tok index:i block:b
    type := t.
    index := i.
    block := b.
    token := tok.
    name := n
!

name
    ^ name
!

index
    ^ index
! !

!VariableNode methodsFor:'evaluating'!

evaluate
    (type == #MethodVariable) ifTrue:[
        ^ token value
    ].
    (type == #InstanceVariable) ifTrue:[
        ^ selfValue instVarAt:index
    ].
    (type == #BlockArg) ifTrue:[
        ^ token value
    ].
    (type == #GlobalVariable) ifTrue:[
        (Smalltalk includesKey:name) ifTrue:[
            ^ Smalltalk at:name
        ].
"
        self error:('global ' , name , ' is undefined').
"

        ^ UndefinedVariable name:name.
        ^ nil
    ].
    (type == #BlockVariable) ifTrue:[
        ^ token value
    ].
    (type == #ClassVariable) ifTrue:[
        ^ Smalltalk at:name
    ].
    (type == #ClassInstanceVariable) ifTrue:[
        ^ selfClass instVarAt:index
    ].
    (type == #ThisContext) ifTrue:[
        ^ thisContext
    ].
    "not reached"
    self halt:'bad type'.
    ^ value
!

store:aValue
    (type == #MethodVariable) ifTrue:[
        token value:aValue. ^ aValue
    ].
    (type == #InstanceVariable) ifTrue:[
        ^ selfValue instVarAt:index put:aValue
    ].
    (type == #GlobalVariable) ifTrue:[
        ^ Smalltalk at:name put:aValue
    ].
    (type == #ClassVariable) ifTrue:[
        ^ Smalltalk at:name put:aValue
    ].
    (type == #BlockVariable) ifTrue:[
        token value:aValue. ^ aValue
    ].
    (type == #ClassInstanceVariable) ifTrue:[
        ^ selfClass instVarAt:index put:aValue
    ].
    "not reached"
    self halt:'bad type'.
    ^ aValue
! !

!VariableNode methodsFor:'code generation'!

codeForSideEffectOn:aStream inBlock:b
    "no code at all"
    ^ self
!

codeOn:aStream inBlock:codeBlock
    |theCode b deltaLevel|

    (type == #MethodArg) ifTrue:[
        (index <= 4) ifTrue:[
            aStream nextPut:(#(pushMethodArg1
                               pushMethodArg2
                               pushMethodArg3 
                               pushMethodArg4) at:index).
            ^ self
        ].
        aStream nextPut:#pushMethodArg.
        aStream nextPut:index.
        ^ self
    ].
    (type == #MethodVariable) ifTrue:[
        (index <= 6) ifTrue:[
            aStream nextPut:(#(pushMethodVar1
                               pushMethodVar2
                               pushMethodVar3
                               pushMethodVar4
                               pushMethodVar5
                               pushMethodVar6) at:index).
            ^ self
        ].
        aStream nextPut:#pushMethodVar.
        aStream nextPut:index.
        ^ self
    ].
    (type == #InstanceVariable) ifTrue:[
        (index <= 10) ifTrue:[
            theCode := #(pushInstVar1 pushInstVar2 pushInstVar3
                         pushInstVar4 pushInstVar5 pushInstVar6
                         pushInstVar7 pushInstVar8 pushInstVar9
                         pushInstVar10) at:index.
            aStream nextPut:theCode.
            ^ self
        ].
        aStream nextPut:#pushInstVar.
        aStream nextPut:index.
        ^ self
    ].
    (type == #BlockArg) ifTrue:[
        "find deltaLevel to block, where argument was defined"
        b := codeBlock.
        deltaLevel := 0.
        [b notNil and:[b ~~ block]] whileTrue:[
            b inlineBlock ifFalse:[
                deltaLevel := deltaLevel + 1
            ].
            b := b home
        ].
        (deltaLevel == 0) ifTrue:[
            (index <= 4) ifTrue:[
                theCode := #(pushBlockArg1 pushBlockArg2 pushBlockArg3
                             pushBlockArg4) at:index.
                aStream nextPut:theCode.
                ^ self
            ].
            aStream nextPut:#pushBlockArg.
            aStream nextPut:index
        ] ifFalse:[
            (deltaLevel == 1) ifTrue:[
                aStream nextPut:#pushOuter1BlockArg
            ] ifFalse:[
                (deltaLevel == 2) ifTrue:[
                    aStream nextPut:#pushOuter2BlockArg
                ] ifFalse:[
                    aStream nextPut:#pushOuterBlockArg.
                    aStream nextPut:deltaLevel
                ]
            ].
            aStream nextPut:index
        ].
        ^ self
    ].
    (type == #GlobalVariable) ifTrue:[
        aStream nextPut:#pushGlobal.
        aStream nextPut:name.
        aStream nextPut:0.      "slot for generation "
        aStream nextPut:0.      "slot for cell address (4 byte) "
        aStream nextPut:0.
        aStream nextPut:0.
        aStream nextPut:0.
        ^ self
    ].
    (type == #ClassVariable) ifTrue:[
        aStream nextPut:#pushClassVar.
        aStream nextPut:name.
        aStream nextPut:0.      "slot for generation "
        aStream nextPut:0.      "slot for cell address (4 byte) "
        aStream nextPut:0.
        aStream nextPut:0.
        aStream nextPut:0.
        ^ self
    ].
    (type == #BlockVariable) ifTrue:[
        "find deltaLevel to block, where variable was defined"
        b := codeBlock.
        deltaLevel := 0.
        [b notNil and:[b ~~ block]] whileTrue:[
            b inlineBlock ifFalse:[
                deltaLevel := deltaLevel + 1
            ].
            b := b home
        ].

        (deltaLevel == 0) ifTrue:[
            aStream nextPut:#pushBlockVar.
            aStream nextPut:index
        ] ifFalse:[
            aStream nextPut:#pushOuterBlockVar.
            aStream nextPut:deltaLevel.
            aStream nextPut:index
        ].
        ^ self
    ].
    (type == #ClassInstanceVariable) ifTrue:[
        aStream nextPut:#pushClassInstVar.
        aStream nextPut:index.
        ^ self
    ].
    (type == #ThisContext) ifTrue:[
        aStream nextPut:#pushThisContext. ^ self
    ].

    "can this be reached ?"

    "not reached"
    self halt:'bad type'.

    aStream nextPut:#pushLit.
    aStream nextPut:value
!

codeStoreOn:aStream inBlock:codeBlock valueNeeded:valueNeeded
    |theCode b deltaLevel|

    valueNeeded ifTrue:[
        aStream nextPut:#dup
    ].
    (type == #MethodVariable) ifTrue:[
        (index <= 6) ifTrue:[
            theCode := #(storeMethodVar1 storeMethodVar2
                         storeMethodVar3 storeMethodVar4
                         storeMethodVar5 storeMethodVar6) at:index.
            aStream nextPut:theCode.
            ^ self
        ].
        aStream nextPut:#storeMethodVar.
        aStream nextPut:index.
        ^ self
    ].
    (type == #InstanceVariable) ifTrue:[
        (index <= 10) ifTrue:[
            theCode := #(storeInstVar1 storeInstVar2
                         storeInstVar3 storeInstVar4
                         storeInstVar5 storeInstVar6
                         storeInstVar7 storeInstVar8
                         storeInstVar9 storeInstVar10) at:index.
            aStream nextPut:theCode.
            ^ self
        ].
        aStream nextPut:#storeInstVar.
        aStream nextPut:index.
        ^ self
    ].
    (type == #GlobalVariable) ifTrue:[
        aStream nextPut:#storeGlobal.
        aStream nextPut:name.
        aStream nextPut:0.      "slot for generation "
        aStream nextPut:0.      "slot for cell address (4 byte) "
        aStream nextPut:0.
        aStream nextPut:0.
        aStream nextPut:0.
        ^ self
    ].
    (type == #BlockVariable) ifTrue:[
        "find deltaLevel to block, where variable was defined"
        b := codeBlock.
        deltaLevel := 0.
        [b notNil and:[b ~~ block]] whileTrue:[
            b inlineBlock ifFalse:[
                deltaLevel := deltaLevel + 1
            ].
            b := b home
        ].

        (deltaLevel == 0) ifTrue:[
            aStream nextPut:#storeBlockVar.
            aStream nextPut:index
        ] ifFalse:[
            aStream nextPut:#storeOuterBlockVar.
            aStream nextPut:deltaLevel.
            aStream nextPut:index
        ].
        ^ self
    ].
    (type == #ClassVariable) ifTrue:[
        aStream nextPut:#storeClassVar.
        aStream nextPut:name.
        aStream nextPut:0.      "slot for generation "
        aStream nextPut:0.      "slot for cell address (4 byte) "
        aStream nextPut:0.
        aStream nextPut:0.
        aStream nextPut:0.
        ^ self
    ].
    (type == #ClassInstanceVariable) ifTrue:[
        aStream nextPut:#storeClassInstVar.
        aStream nextPut:index.
        ^ self
    ].
    "cannot be reached"
    ^ self error:'bad assignment'
! !

!VariableNode methodsFor:'printing'!

displayString
    ^ 'InterpreterVariable(' , self printString , ')'
!

printOn:aStream indent:i
    (type == #MethodArg) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #MethodVariable) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #InstanceVariable) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #BlockArg) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #GlobalVariable) ifTrue:[
        aStream nextPutAll:name.^ self
    ].
    (type == #ClassVariable) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #BlockVariable) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #ClassInstanceVariable) ifTrue:[
        aStream nextPutAll:name. ^ self
    ].
    (type == #ThisContext) ifTrue:[
        aStream nextPutAll:'thisContext'. ^ self
    ].
    "not reached"
    self halt:'bad type'.
! !