Fixes for the Debugger to prevent crashes when debugging protected blocks:
Thanks to Manfred Möbus for this!
!Process methods ! dropFrames: frameCount "Private - discard the top <frameCount> stack frames from the receiver's stack. Requires that the receiver not be active. Assumes the receiver is being debugged." | topFrameBeforeResumption sendFrameBeforeResumption runableBeforeResumption homeFrame | self == CurrentProcess ifTrue: [ ^self error: 'cannot drop frames from the active process.' ]. frameCount = 0 ifTrue: [ ^self ]. self class enableInterrupts: false. sendFrameBeforeResumption := sendFrame. topFrameBeforeResumption := self topFrame. runableBeforeResumption := self runable. self sendFrame: ( self processIndexToStackPointer: topFrameBeforeResumption ). self debugger notNil ifTrue: [ self debugger debuggingProcess: CurrentProcess ]. [ self protectionBlock: ( self firstProtectionBlockWithin: frameCount removeMark: true ). self protectionBlock ~~ nil ] whileTrue: [ self debugger notNil ifTrue: [ "mm: added 'if > 0' check; expandFrame: would fail, and it is the wrong frame anyway - see homeFrameOfContext: which in some cases just returns 0 for 'no-valid-result' " (homeFrame := self homeFrameOfContext: self protectionBlock ) > 0 ifTrue: [ self debugger expandFrame: homeFrame ].]. self evaluateOneProtectionBlock ]. self debugger notNil ifTrue: [ self debugger debuggingProcess: nil ]. self runable: runableBeforeResumption. self topFrame = topFrameBeforeResumption ifTrue: [ frameCount timesRepeat: [ self dropFrameWithoutProtection]. sendFrame := sendFrameBeforeResumption]! ! !Debugger methods ! expandFrame: frame "Private - create a debugging version of a frame." | process cm dcm offset oldOffset interruptFrame arg | "mm: get out for frame=0 - this will fail since returnOffsetAt: -1 will return wrong value and make #convert:to:offset: blow up the image - the real return value is probably (self at: 2) but this is unconfirmed - so for the while just don't expand this frame" frame = 0 ifTrue: [ ^self ]. process := self debuggedProcess. cm := process methodAt: frame. cm isDebuggable ifTrue: [ cm sourceIndex >= 3 "method source in dll" ifTrue: [ cm sourceObject: ( ( process receiverAt: frame ) methodFor: cm selector in: cm classField ) sourceString ] ] ifFalse: [ interruptFrame := false. oldOffset := (process returnOffsetAt: frame - 1). (oldOffset = 0) ifTrue: [ interruptFrame := true. oldOffset := process frameAt: frame - 1 offset: 7]. (oldOffset = 1) ifTrue: [^self]. dcm := cm asDebuggableMethod. offset := self convert: cm to: dcm offset: oldOffset. "mm: make block contexts consistent with the replaced compiled method - this was found necessary only for the protected frame (#ensure: or #ifCurtailed) as invoked by #hop-ing through a ^ return from block. The vm gets fooled by old and new return addresses in the next #copyStack in this case, and when the debugger calls #convert:to:offset with wrong values, a GPF results. " 1 to: (process argumentCount: frame - 1) do: [ :i | arg := process stackArgAt: frame - 1 number: i. arg isBlockClosure ifTrue: [ (arg at: 1) == cm ifTrue: [ arg at: 1 put: dcm. ]]]. process methodAt: frame put: dcm. interruptFrame ifTrue: [ process frameAt: frame - 1 offset: 7 put: offset] ifFalse: [ process returnOffsetAt: frame - 1 put: offset ] ]! ! !Debugger methods ! hop "Private - resume process for one hop, i.e., to next expression or assignment at any method level." | process protectedFrameIndex | self resumable ifFalse: [^self]. process := self debuggedProcess. realFrame == nil ifFalse: [process topFrame: realFrame. realFrame := nil]. self expandFrame: 2. self expandFrame: 3. "mm: ensure hopping (with ^ ) out of a block into protected frame will find its method already debuggable; otherwise VM would do this in assembler code, but does not implement the changes to blocks as added to #expandFrame: method" self inBlock ifTrue: [ protectedFrameIndex := process firstProtectionFrame. protectedFrameIndex notNil ifTrue: [ self expandFrame: protectedFrameIndex + 1. ].]. self label: 'hopping'. Process enableInterrupts: false. process sendFrame: 1. process debugger: self. process interruptFrame: 0. process runable: (process runable bitOr: 1). BreakPoints:= breakpointArray. UserInterfaceProcess := (process isUserIF ifTrue: [process] ifFalse: [nil]). CurrentProcess := process. process resume: 0! ! !Process methods ! firstProtectionFrame "Private - added by mm: answer the frame number of the first protection block in this process, or nil if none exists. (this is the frame where receiverAt: frame will return the FrameMarker, with the method #setUnwind: )." | count index | count := 0. index := self processIndexFromBPLink: self topFrame. [(self at: index) ~= 0 ] whileTrue: [ FrameMarker == (self at: index + ReceiverOffset) ifTrue: [^count ]. count := count + 1. index := self nextFrameFrom: index]. ^nil! !