"{ Package: 'ctu:ircompiler' }"
Object subclass:#IRStackCount
instanceVariableNames:'start position length'
classVariableNames:''
poolDictionaries:''
category:'NewCompiler-Bytecode'
!
IRStackCount comment:'This keeps track of the stack count for the BytecodeGenerator.'
!
!IRStackCount class methodsFor:'instance creation'!
new
^ super new startAt: 0
! !
!IRStackCount class methodsFor:'as yet unclassified'!
startAt: pos
^ super new startAt: pos
! !
!IRStackCount methodsFor:'affecting'!
pop
^ self pop: 1
!
pop: n
(position _ position - n) "< 0
ifTrue: [self error: 'Parse stack underflow']"
!
push
^ self push: 1
!
push: n
(position _ position + n) > length
ifTrue: [length _ position]
! !
!IRStackCount methodsFor:'comparing'!
= other
^ self class == other class
and: [start = other start
and: [position = other position
and: [length = other size]]]
!
hash
^ position hash bitXor: (length hash bitXor: start hash)
! !
!IRStackCount methodsFor:'error handling'!
errorStackOutOfSync: aStackCount
self error: 'stack not in sync!!'.
! !
!IRStackCount methodsFor:'initialize'!
startAt: pos
start _ position _ length _ pos
! !
!IRStackCount methodsFor:'printing'!
printOn: aStream
super printOn: aStream.
aStream
nextPutAll: ' start '; print: start;
nextPutAll: ' stop '; print: position;
nextPutAll: ' max '; print: length.
! !
!IRStackCount methodsFor:'results'!
length
^length
!
linkTo: stackOrNil
stackOrNil ifNil: [^ self class startAt: self position].
^ self position = stackOrNil start
ifTrue: [stackOrNil]
ifFalse: [self errorStackOutOfSync: stackOrNil]
!
position
^position
!
size
^length
!
start
^ start
! !
!IRStackCount class methodsFor:'documentation'!
version
^ '$Id$'
!
version_CVS
^ 'Header: /cvs/stx/cvut/stx/goodies/newcompiler/IRStackCount.st,v 1.3 2009/10/08 11:59:57 fm Exp '
!
version_SVN
^ '$Id:: $'
! !