"

 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

!

!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

"

! !

!VariableNode class methodsFor:'instance creation'!

type:t class:class name:n

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

!

type:t index:i selfValue:s

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

!

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

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

!

type:t name:n value:val

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

!

type:t token:tok

    ^ (self basicNew) type:t token:tok

!

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'!

index

    ^ index

!

name

    ^ name

!

type:t class:class name:n

    type := t.

    value := nil.

    name := n.

    selfClass := class 

!

type:t index:i selfValue:s

    type := t.

    value := nil.

    index := i.

    selfValue := s

!

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:b

    type := t.

    index := i.

    block := b.

    token := tok.

    name := n

!

type:t name:n value:val

    type := t.

    name := n.

    value := val

!

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

! !

!VariableNode methodsFor:'code generation'!

codeForSideEffectOn:aStream inBlock:b for:aCompiler

    "no code at all"

    ^ self

!

codeOn:aStream inBlock:codeBlock for:aCompiler

    |theCode b deltaLevel litIndex|

    (type == #MethodArg) ifTrue:[

    ].

    (type == #MethodVariable) ifTrue:[

    ].

    (type == #InstanceVariable) ifTrue:[

    ].

    (type == #BlockArg) ifTrue:[

    ].

    (type == #GlobalVariable) ifTrue:[

"/        aStream nextPut:#pushGlobal; nextPut:name.

    ].

    (type == #ClassVariable) ifTrue:[

"/        aStream nextPut:#pushClassVar; nextPut:(selfClass name , ':' , name) asSymbol.

    ].

    (type == #BlockVariable) ifTrue:[

    ].

    (type == #ClassInstanceVariable) ifTrue:[

    ].

    (type == #ThisContext) ifTrue:[

    ].

    "not reached"

    self halt:'bad type'.

!

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

    |theCode b deltaLevel litIndex|

    valueNeeded ifTrue:[

    ].

    (type == #MethodVariable) ifTrue:[

    ].

    (type == #InstanceVariable) ifTrue:[

    ].

    (type == #BlockVariable) ifTrue:[

    ].

    (type == #GlobalVariable) ifTrue:[

"/        aStream nextPut:#storeGlobal; nextPut:name.

    ].

    (type == #ClassVariable) ifTrue:[

"/        aStream nextPut:#storeClassVar; nextPut:(selfClass name , ':' , name) asSymbol.

    ].

    (type == #ClassInstanceVariable) ifTrue:[

    ].

    "not reached"

    ^ self error:'bad assignment'

! !

!VariableNode methodsFor:'evaluating'!

evaluate

    (type == #MethodVariable

    or:[type == #BlockArg

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

	^ token variableValue

    ].

    (type == #InstanceVariable) ifTrue:[

	^ selfValue instVarAt:index

    ].

    (type == #GlobalVariable) ifTrue:[

	(Smalltalk includesKey:name) ifTrue:[

	    ^ Smalltalk at:name

	].

"

	self error:('global ' , name , ' is undefined').

"

	^ UndefinedVariable name:name.

	^ nil

    ].

    (type == #ClassVariable) ifTrue:[

	^ Smalltalk at:(selfClass name , ':' , name) asSymbol

    ].

    (type == #ClassInstanceVariable) ifTrue:[

	^ selfClass instVarAt:index

    ].

    (type == #ThisContext) ifTrue:[

	^ thisContext

    ].

    "not reached"

    self halt:'bad type'.

    ^ value

!

store:aValue

    (type == #MethodVariable

    or:[type == #BlockVariable]) 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:(selfClass name , ':' , name) asSymbol put:aValue

    ].

    (type == #ClassInstanceVariable) ifTrue:[

	^ selfClass instVarAt:index put:aValue

    ].

    "not reached"

    self halt:'bad type'.

    ^ aValue

! !

!VariableNode methodsFor:'printing'!

displayString

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

!

printOn:aStream indent:i

    (type == #MethodArg              "/ actually only a debug-check

    or:[type == #MethodVariable

    or:[type == #InstanceVariable

    or:[type == #BlockArg

    or:[type == #GlobalVariable

    or:[type == #ClassVariable

    or:[type == #BlockVariable

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

	aStream nextPutAll:name. ^ self

    ].

    (type == #ThisContext) ifTrue:[

	aStream nextPutAll:'thisContext'. ^ self

    ].

    "not reached"

    self halt:'bad type'.

! !

!VariableNode methodsFor:'queries'!

isGlobal

    "return true, if this is a node for a global variable"

    ^ (type == #GlobalVariable) and:[Smalltalk includesKey:name]

! !