"

 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.

"

"{ Package: 'stx:libcomp' }"

"{ NameSpace: Smalltalk }"

PrimaryNode subclass:#VariableNode

	instanceVariableNames:'name token 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'!

blockArgumentNamed:n

    ^ (self basicNew) type:#BlockArg name:n asSymbol

    "Created: / 22-10-2006 / 11:59:10 / cg"

!

globalNamed:n                                   

    "because this is called even for invalid (partial) names,

     and we do not want to create zillions of unused symbols,

     no asSymbol is done here. So the name kept is actually a string.

     A symbol will be created when code is actually created for it"

    ^ (self basicNew) type:#GlobalVariable name:n "asSymbol"

    "Modified (comment): / 29-08-2013 / 01:10:02 / cg"

!

methodArgumentNamed:n

    ^ (self basicNew) type:#MethodArg name:n asSymbol

    "Created: / 06-08-2006 / 01:12:55 / cg"

!

methodLocalNamed:n

    ^ (self basicNew) type:#MethodVariable name:n asSymbol

    "Created: / 06-08-2006 / 13:43:41 / cg"

!

type:t class:class name:n

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

!

type:t context:aContext

    ^ (self basicNew) type:t context:aContext

    "Created: / 17.1.1998 / 04:00:35 / cg"

!

type:t holder:holder name:n

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

!

type:t name:n

    ^ (self basicNew) type:t name:n

!

type:t name:n context:aContext index:i

    ^ (self basicNew) type:t name:n context:aContext index:i

    "Created: / 17.1.1998 / 02:40:32 / cg"

!

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"

!

block:something

    block := something.

!

index

    ^ index

!

index:anIntegerIndex

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    "Modified: / 15-11-2011 / 19:10:08 / cg"

!

name

    type == #ThisContext ifTrue:[ ^ 'thisContext' ].

    ^ name

    "Modified: / 23-09-2014 / 14:08:41 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

name:something

    name := something.

    "Modified: / 28-06-2011 / 22:14:40 / cg"

!

token

    ^ token

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

!

token:something

    token := something.

!

type

    ^ type

!

type:t class:class name:n

    "/ type == #PoolVariable ifTrue:[self breakPoint:#cg].

    type := t.

    name := n.

    value := class

    "Modified: / 17.1.1998 / 04:03:55 / cg"

!

type:t context:aContext

    type := t.

    value := aContext.

    "Modified: / 17.1.1998 / 04:01:55 / cg"

!

type:t holder:holder name:n

    type := t.

    token := holder.

    name := n

!

type:t name:n

    type := t.

    value := nil.

    name := n

!

type:t name:n context:aContext index:anIntegerIndex

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    value := aContext.

    name := n

    "Created: / 17-01-1998 / 02:40:55 / cg"

    "Modified: / 15-11-2011 / 19:10:18 / cg"

!

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

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    value := s.

    name := n

    "Modified: / 15-11-2011 / 19:10:21 / cg"

!

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

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    value := s.

    name := n

    "Modified: / 15-11-2011 / 19:10:24 / cg"

!

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

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    token := tok.

    name := n

    "Modified: / 15-11-2011 / 19:10:30 / cg"

!

type:t name:n token:tok index:anIntegerIndex block:variableBlock from:codeBlock

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    block := variableBlock.

    token := tok.

    name := n.

    (type == #BlockArg) ifTrue:[

        variableBlock blockArgAccessed:true.

    ].

    codeBlock ~~ variableBlock ifTrue:[

        codeBlock rememberOuterBlockVarAccess:self

    ]

    "Created: / 02-07-1997 / 10:54:50 / cg"

    "Modified: / 15-11-2011 / 19:10:35 / cg"

!

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

    type := t.

"/    self assert:(anIntegerIndex isNil or:[anIntegerIndex ~~ 0]).

    index := anIntegerIndex.

    block := b.

    token := tok.

    (type == #BlockArg) ifTrue:[

        b blockArgAccessed:true.

    ].

    "Modified: / 15-11-2011 / 19:10:04 / cg"

! !

!VariableNode methodsFor:'code generation'!

codeForSideEffectOn:aStream inBlock:b for:aCompiler

    "no code at all"

    aCompiler 

        warning:'Useless variable reference'

        position:startPosition to:endPosition.    

    ^ self

!

codeForSimpleReturnOn:aStream inBlock:b lineNumber:lineNrOrNil for:aCompiler

    |code idx|

    lineNrOrNil notNil ifTrue:[

        self codeLineNumber:lineNrOrNil on:aStream for:aCompiler

    ].

    (type == #InstanceVariable) ifTrue:[

        (index <= 8) ifTrue:[

            code := #( retInstVar1

                       retInstVar2

                       retInstVar3

                       retInstVar4

                       retInstVar5

                       retInstVar6

                       retInstVar7

                       retInstVar8) at:index.

            aStream nextPut:code.

            ^ self

        ].

    ].

    (type == #MethodVariable) ifTrue:[

        idx := index.

        idx isNil ifTrue:[ idx := self indexIn: aCompiler ].

        (idx <= 6) ifTrue:[

            code := #( retMethodVar1

                       retMethodVar2

                       retMethodVar3

                       retMethodVar4

                       retMethodVar5

                       retMethodVar6) at:idx.

            aStream nextPut:code.

            ^ self

        ].

    ].

    (type == #MethodArg) ifTrue:[

        idx := index.

        idx isNil ifTrue:[ idx := self indexIn: aCompiler ].

        (idx <= 2) ifTrue:[

            code := #(retMethodArg1

                      retMethodArg2) at:idx.

            aStream nextPut:code.

            ^ self

        ]

    ].

    "/ anything else must be pushed, then top returned

    self codeOn:aStream inBlock:b for:aCompiler.

    aStream nextPut:#retTop

    "Modified: / 06-08-2006 / 22:59:28 / cg"

    "Modified (comment): / 25-01-2018 / 19:26:46 / mawalch"

!

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

    |theCode b deltaLevel litIndex specialGlobalIndex

     bvIdx bvTyp blocksCode selLitIdx |

    (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:[

        "for browsing, we put it into the literal-array; even if it's a specal global"

        litIndex := aCompiler addLiteral:name asSymbol.

        specialGlobalIndex := aCompiler specialGlobalCodeFor:name.

        specialGlobalIndex notNil ifTrue:[

            aStream nextPut:#pushSpecialGlobal; nextPut:specialGlobalIndex.