"

 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 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.

"

!

documentation

"

    node for parse-trees, representing variables

    This is a helper class for the compiler.

    [author:]

        Claus Gittinger

"

! !

!VariableNode class methodsFor:'instance creation'!

type:t class:class name:n

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

!

type:t name:n

    ^ (self basicNew) type:t name:n

!

type:t name:n index:i selfClass:s

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

!

type:t name:n index:i selfValue:s

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

!

type:t name:n token:tok index:i

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

!

type:t name:n token:tok index:i block:b from:codeBlock

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

    "Modified: 2.7.1997 / 10:55:48 / cg"

! !

!VariableNode methodsFor:'accessing'!

block

    ^ block

    "Created: 2.7.1997 / 18:53:38 / cg"

!

index

    ^ index

!

name

    ^ name

!

type:t class:class name:n

    type := t.

    value := nil.

    name := n.

    selfClass := class 

!

type:t name:n

    type := t.

    value := nil.

    name := n

!

type:t name:n index:i selfClass:s

    type := t.

    value := nil.

    index := i.

    selfClass := s.

    name := n

!

type:t name:n index:i selfValue:s

    type := t.

    value := nil.

    index := i.

    selfValue := 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:variableBlock from:codeBlock

    type := t.

    index := i.

    block := variableBlock.

    token := tok.

    name := n.

    (type == #BlockArg) ifTrue:[

        variableBlock blockArgAccessed:true.

    ].

    codeBlock ~~ variableBlock ifTrue:[

        codeBlock rememberOuterBlockVarAccess:self

    ]

    "Created: 2.7.1997 / 10:54:50 / cg"

    "Modified: 2.7.1997 / 11:12:58 / cg"

!

type:t token:tok index:i block:b

    type := t.

    index := i.

    block := b.

    token := tok.

    (type == #BlockArg) ifTrue:[

        b blockArgAccessed:true.

    ].

    "Modified: 18.6.1997 / 11:41:05 / cg"

! !

!VariableNode methodsFor:'code generation'!

codeForSideEffectOn:aStream inBlock:b for:aCompiler

    "no code at all"

    ^ self

!

codeLoadOn:aStream type:type index:index inBlock:codeBlock for:aCompiler

    |theCode b deltaLevel litIndex specialGlobalIndex

     bvIdx bvTyp blocksCode|

    (type == #MethodArg) ifTrue:[

        (index <= 4) ifTrue:[

            aStream nextPut:(#(pushMethodArg1

                               pushMethodArg2

                               pushMethodArg3 

                               pushMethodArg4) at:index).

            ^ self

        ].

        aStream nextPut:#pushMethodArg; nextPut:index.

        ^ self

    ].

    (type == #MethodVariable) ifTrue:[

        (index <= 6) ifTrue:[

            aStream nextPut:(#(pushMethodVar1

                               pushMethodVar2

                               pushMethodVar3

                               pushMethodVar4

                               pushMethodVar5

                               pushMethodVar6) at:index).

            ^ self

        ].

        aStream nextPut:#pushMethodVar; 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; nextPut:index.

        ^ self

    ].

    ((type == #BlockArg) 

    or:[type == #BlockVariable]) ifTrue:[

        "/ compiling for codeBlock; accessing variable in block.

        bvIdx := index.

        bvTyp := type.

        "/ find the context where that variable is contained physically

        blocksCode := block.

        [blocksCode notNil and:[blocksCode isInlineBlock]] whileTrue:[

            blocksCode := blocksCode home

        ].

        "/ find deltaLevel from code-context to the containing block

        b := codeBlock.

        deltaLevel := 0.

        [b notNil and:[b ~~ blocksCode]] whileTrue:[

            b isInlineBlock ifFalse:[

                deltaLevel := deltaLevel + 1

            ].

            b := b home

        ].

        b isNil ifTrue:[

            codeBlock isNil ifTrue:[

                "/ a var of a block which is inlined in the method. 

                "/ Generate a pushMVAR

                bvIdx := block indexOfFirstTemp + index - 1.

                type == #BlockVariable ifTrue:[

                    bvIdx := bvIdx + block numArgs

                ].

                ^ self 

                    codeLoadOn:aStream

                    type:#MethodVariable

                    index:bvIdx

                    inBlock:codeBlock

                    for:aCompiler

            ].

            "/ a var of a block which is inlined in the outer block.

            "/ Generate a pushBVAR

            bvIdx := block indexOfFirstTemp + index - 1.

            type == #BlockVariable ifTrue:[

                bvIdx := bvIdx + block numArgs

            ].

            bvTyp := #BlockVariable.

        ] ifFalse:[

            block isInlineBlock ifTrue:[

                "/ a var of a block which is inlined in another block.

                "/ Generate a pushBVAR / pushOuterBVAR

                bvIdx := block indexOfFirstTemp + index - 1.

                type == #BlockVariable ifTrue:[

                    bvIdx := bvIdx + block numArgs

                ].

                bvTyp := #BlockVariable.

            ]

        ].

        (bvTyp == #BlockVariable) ifTrue:[

            (deltaLevel == 0) ifTrue:[

                bvIdx <= 3 ifTrue:[

                    aStream nextPut:(#(pushBlockVar1 pushBlockVar2 pushBlockVar3) at:bvIdx).

                    ^ self

                ].

                aStream nextPut:#pushBlockVar.

            ] ifFalse:[

                aStream nextPut:#pushOuterBlockVar; nextPut:deltaLevel.

            ].

        ] ifFalse:[

            (deltaLevel == 0) ifTrue:[

                (bvIdx <= 4) ifTrue:[

                    aStream nextPut:(#(pushBlockArg1 pushBlockArg2 pushBlockArg3

                                       pushBlockArg4) at:bvIdx).

                    ^ self

                ].

                aStream nextPut:#pushBlockArg.

            ] ifFalse:[

                (deltaLevel == 1) ifTrue:[

                    aStream nextPut:#pushOuter1BlockArg

                ] ifFalse:[

                    (deltaLevel == 2) ifTrue:[

                        aStream nextPut:#pushOuter2BlockArg

                    ] ifFalse:[

                        aStream nextPut:#pushOuterBlockArg; nextPut:deltaLevel

                    ]

                ].

            ].

        ].

        aStream nextPut:bvIdx.

        ^ self

    ].

    (type == #GlobalVariable) ifTrue:[

        litIndex := aCompiler addLiteral:name asSymbol.

        specialGlobalIndex := aCompiler specialGlobalCodeFor:name.

        specialGlobalIndex notNil ifTrue:[

            aStream nextPut:#pushSpecialGlobal; nextPut:specialGlobalIndex.

            ^ self

        ].

        litIndex < 256 ifTrue:[

            aStream nextPut:#pushGlobalS; nextPut:litIndex

        ] ifFalse:[

            aStream nextPut:#pushGlobalL; nextPut:litIndex; nextPut:0

        ].

        ^ self

    ].

    (type == #ClassVariable) ifTrue:[

        litIndex := aCompiler addLiteral:(selfClass name , ':' , name) asSymbol.

        litIndex < 256 ifTrue:[

            aStream nextPut:#pushClassVarS; nextPut:litIndex

        ] ifFalse:[

            aStream nextPut:#pushClassVarL; nextPut:litIndex; nextPut:0

        ].

        ^ self

    ].

    (type == #PrivateClass) ifTrue:[

        litIndex := aCompiler addLiteral:(selfClass name , '::' , name) asSymbol.

        litIndex < 256 ifTrue:[

            aStream nextPut:#pushGlobalS; nextPut:litIndex

        ] ifFalse:[

            aStream nextPut:#pushGlobalL; nextPut:litIndex; nextPut:0

        ].

        ^ self

    ].

    (type == #ClassInstanceVariable) ifTrue:[

        aStream nextPut:#pushClassInstVar; nextPut:index.

        ^ self

    ].

    (type == #ThisContext) ifTrue:[

        aStream nextPut:#pushThisContext. ^ self

    ].

    "not reached"

    self halt:'bad type'.

    "Created: 25.6.1997 / 16:14:17 / cg"

    "Modified: 26.6.1997 / 10:15:11 / cg"

!

codeOn:aStream inBlock:codeBlock for:aCompiler

    self

        codeLoadOn:aStream type:type index:index inBlock:codeBlock for:aCompiler

    "Modified: 26.6.1997 / 10:06:10 / cg"

!

codeStoreOn:aStream inBlock:codeBlock valueNeeded:valueNeeded for:aCompiler

    self

        codeStoreOn:aStream type:type index:index

        inBlock:codeBlock valueNeeded:valueNeeded for:aCompiler

    "Modified: 25.6.1997 / 16:15:28 / cg"

!

codeStoreOn:aStream type:type index:index inBlock:codeBlock valueNeeded:valueNeeded for:aCompiler

    |theCode b deltaLevel litIndex bvIdx blocksCode|

    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; 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; nextPut:index.

        ^ self

    ].

    (type == #BlockVariable) ifTrue:[

        bvIdx := index.

        "/ find the context where that variable is contained physically

        blocksCode := block.

        [blocksCode notNil and:[blocksCode isInlineBlock]] whileTrue:[

            blocksCode := blocksCode home

        ].

        "find deltaLevel to block, where variable was defined"

        b := codeBlock.

        deltaLevel := 0.

        [b notNil and:[b ~~ blocksCode]] whileTrue:[

            b isInlineBlock ifFalse:[

                deltaLevel := deltaLevel + 1

            ].

            b := b home

        ].

        b isNil ifTrue:[

            codeBlock isNil ifTrue:[

                "/ a block which is inlined in the method. 

                "/ Generate a pushMVAR

                bvIdx := block indexOfFirstTemp + index - 1.

                bvIdx := bvIdx + block numArgs.

                ^ self

                    codeStoreOn:aStream 

                    type:#MethodVariable index:bvIdx 

                    inBlock:codeBlock 

                    valueNeeded:false       "/ already dupped if value is needed

                    for:aCompiler

            ].

            "/ a var of a block which is inlined in the outer block.

            "/ Generate a pushBVAR

            bvIdx := block indexOfFirstTemp + index - 1.

            bvIdx := bvIdx + block numArgs.

        ] ifFalse:[

            block isInlineBlock ifTrue:[

                "/ a var of a block which is inlined in another block.

                "/ Generate a pushBVAR / pushOuterBVAR

                bvIdx := block indexOfFirstTemp + index - 1.

                bvIdx := bvIdx + block numArgs.

            ]

        ].

        (deltaLevel == 0) ifTrue:[

            bvIdx <= 3 ifTrue:[

                aStream nextPut:(#(storeBlockVar1 storeBlockVar2 storeBlockVar3) at:bvIdx).

                ^ self

            ].

            aStream nextPut:#storeBlockVar

        ] ifFalse:[

            aStream nextPut:#storeOuterBlockVar; nextPut:deltaLevel

        ].

        aStream nextPut:bvIdx.

        ^ self

    ].

    (type == #GlobalVariable) ifTrue:[

        litIndex := aCompiler addLiteral:name asSymbol.

        litIndex < 256 ifTrue:[

            aStream nextPut:#storeGlobalS; nextPut:litIndex

        ] ifFalse:[

            aStream nextPut:#storeGlobalL; nextPut:litIndex; nextPut:0

        ].

        ^ self

    ].

    (type == #ClassVariable) ifTrue:[

        litIndex := aCompiler addLiteral:(selfClass name , ':' , name) asSymbol.

        litIndex < 256 ifTrue:[

            aStream nextPut:#storeClassVarS; nextPut:litIndex

        ] ifFalse:[

            aStream nextPut:#storeClassVarL; nextPut:litIndex; nextPut:0

        ].

        ^ self

    ].

    (type == #ClassInstanceVariable) ifTrue:[

        aStream nextPut:#storeClassInstVar; nextPut:index.

        ^ self

    ].

    "not reached"

    ^ self error:'bad assignment'

    "Created: 25.6.1997 / 16:14:40 / cg"

    "Modified: 26.6.1997 / 10:18:53 / cg"