And by changing last line of this piece of code in #transformToDo:
test := MessageNode new
receiver: blockVar
selector: (increment key > 0 ifTrue:
[#<=] ifFalse: [#>=])
arguments: (Array with: limit)
precedence: precedence from: encoder
sourceRange: (myRange first to: blockRange last).
I get a "correct" selection...
Nicolas
2011/8/25 Nicolas Cellier <[email protected]>:
> A few more notes:
>
> - Encoder>>rawSourceRanges answer a mapping AST Node -> sourceRange
> Gnerally, I would expect sourceRange to be an Interval, but this has
> to be confirmed.
> Theses ranges are constructed at source code Parse time (see senders
> of #noteSourceRange:forNode:)
> - The program counters are assigned to AST nodes at byte code #generate time
> - for inlined macros, like #to:do: in our case, this pc is after the
> initialize and test statements.
>
> in CompiledMethod>>#rawSourceRangesAndMethodDo:
> I just evaluated this:
>
> methNode encoder rawSourceRanges collect: [:ival |
> sourceText copyFrom: ival first to: ival last]
>
> And what I see is that the original to:do: message (before macros
> inlining) has the right range
> {1
> to: 5
> do: [:index |
> temp := index.
> collection
> add: [temp]]}->a Text for 'to: 5 do: [ :index |
> temp := index.
> collection add: [ temp ] ]'
> This node is the original #to:do: and has pc=42
>
> There is also
> {a LeafNode}->a Text for '[ :index |
> temp := index.
> collection add: [ temp ] ]'
> which has a nil pc so it won't be taken into account in the source map.
>
> But one of the messages produced by the inlining has this curious range:
> {index <= 5}->a Text for 'to: 5 do: [ :index |
> temp := index.
> c'
> This node has pc = 40, so it will be selected before the correct one
> above has a chance to be.
> {index <= 5} is the test statement produced by inlining, and this
> seems to be the incorrect highlighting we see.
> Thus we know we have to concentrate on macro inlining.
> This happens in MessageNode>>transformToDo:
> We'll see this.
>
> In the interim, I played with eliminating the nodes having unitilialized pc
> Let us try to evaluate this snippet in debugger's inspector:
> (methNode encoder rawSourceRanges keys select: [:e | e pc > 0])
> collect: [:node |
> | ival |
> ival := methNode encoder rawSourceRanges at: node.
> node -> (sourceText copyFrom: ival first to: ival last)]
>
> Oh god, a bug in the debugger:
> DoItIn: homeContext
> ^ ((homeContext namedTempAt: 2) encoder rawSourceRanges keys
> select: [:e | e pc > 0])
> collect: [:node |
> | ival |
> ival := (node namedTempAt: 2) encoder rawSourceRanges
> at: node.
> node
> -> (sourceText copyFrom: ival first to: ival
> last)]
> (node namedTempAt: 2) does not mean a thing...
> A confusion occurred between the homeContext (DoItIn: method argument)
> and node (the block argument)
> Nevermind... forget about it.
>
> Now let's just concentrate on MessageNode>>transformToDo:
> We see this code:
> test := MessageNode new
> receiver: blockVar
> selector: (increment key > 0 ifTrue: [#<=]
> ifFalse: [#>=])
> arguments: (Array with: limit)
> precedence: precedence from: encoder
> sourceRange: (myRange first to: blockRange
> first).
>
> So the intention seems to select 'to: 5 do: '
>
> But we see this:
> BlockNode>>noteSourceRangeStart:end:encoder:
> "Note two source ranges for this node. One is for the debugger
> and is of the last expression, the result of the block. One is for
> source analysis and is for the entire block."
> encoder
> noteSourceRange: (start to: end)
> forNode: self closureCreationNode.
> startOfLastStatement
> ifNil:
> [encoder
> noteSourceRange: (start to: end)
> forNode: self]
> ifNotNil:
> [encoder
> noteSourceRange: (startOfLastStatement to: end
> - 1)
> forNode: self]
>
> So it seems intentional to select only the last instruction of the
> block for the debugger.
> We'd better not change this without prior asking Eliot.
> But obviously, this is not what is expected by the #transformToDo:
>
> Nicolas
>
> 2011/8/25 Stéphane Ducasse <[email protected]>:
>> tx nicolas this is a cool way to help :)
>>
>> Stef
>>
>> On Aug 24, 2011, at 9:54 PM, Nicolas Cellier wrote:
>>
>>> So the entries of interest for highlighting are
>>>
>>> Debugger>>contentsSelection
>>> Debugger>>pcRange
>>> CompiledMethod>>debuggerMap
>>> DebuggerMethodMap class>>forMethod:
>>> DebuggerMethodMap>>rangeForPC:contextIsActiveContext:
>>>
>>> Then you see the DebuggerMethodMap>>forMethod:methodNode: takes both a
>>> CompiledMethod and its #methodNode.
>>> CompiledMethod>>methodNode invokes the Parser to get the
>>> AbstractSyntaxTree from method source, and if it ever fails ends up by
>>> trying to decompile the byteCodes.
>>>
>>> This is the easy part. Now we to deal with #abstractPCForConcretePC:
>>> and #abstractSourceMap.
>>>
>>> By reading CompiledMethod>>abstractPCForConcretePC: you should quickly
>>> understand that a concrete PC is a byte offset of current byteCode
>>> (the offsets displayed in the byteCode view) while the abstractPC is
>>> just the rank of current byteCode in the list of byteCodes
>>> instructions composing the CompiledMethod. This is just because
>>> "byteCodes" may spread on several bytes beside their name...
>>> This will use InstructionStream and InstructionClient which are just
>>> an iterator and a sort of visitor on byteCode instructions.
>>> So this is not really interesting.
>>>
>>> The more interesting part is #abstractSourceMap
>>> There is a first step to obtain CompiledMethod>>rawSourceRangesAndMethodDo:
>>> This is the most important part.
>>> The rest is again a mapping from concretePC (instruction byte offset)
>>> to abstractPC (instruction rank).
>>> And some build of a dictionary mapping instruction rank (abstractPC)
>>> -> selected range.
>>>
>>> Note that the last trick seems to use a regenerated CompiledMethod
>>> (theMethodToScan) rather than the original CompiledMethod. There is no
>>> assertion whether these two are equivalent or not. A priori, they
>>> should, unless the Compiler changed since last compilation or if its
>>> behaviour is affected by some Preferences... Would we introduce some
>>> customizable Compiler optimizations that this could become a problem
>>> (We would then add to map decompiled AST to source code AST, probably
>>> with guesses, unless the CompiledMethod would contain debugger
>>> friendly hints...)
>>> We will consider this is not a problem by now.
>>>
>>> So let's now concentrate on rawSourceRangesAndMethodDo:
>>> The nice thing is that you now can just debug this
>>>
>>> (ClosureTests>>#testToDoOutsideTemp) methodNode
>>> rawSourceRangesAndMethodDo: [:rs :mth | ]
>>>
>>> and see how it goes in Squeak. I did not look in Pharo yet, but I
>>> would be amazed to see it much different.
>>> It's now late, and my spare time is off, but you have clues to get
>>> more insights. I wish you good debugging, and come back to me if it
>>> ever goes in deeper complications.
>>>
>>> Cheers
>>>
>>> Nicolas
>>>
>>> 2011/8/24 Michael Roberts <[email protected]>:
>>>>
>>>>>
>>>>> Ok I'm curious to know then.
>>>>
>>>> Here is a little trace from this example method:
>>>>
>>>> toDoOutsideTemp
>>>> | temp collection |
>>>> collection := OrderedCollection new.
>>>> 1 to: 5 do: [ :index |
>>>> temp := index.
>>>> collection add: [ temp ] ]
>>>>
>>>> Trace is start,stop position of the highlight for each 'step over'.
>>>>
>>>> Whilst the numbers are hard to visualise, below you can see how they
>>>> slightly diverge.
>>>> Left Pharo Right Squeak
>>>>
>>>> 50, 73 71, 73 diff
>>>> 71, 73 71, 73
>>>> 50, 73 50, 73
>>>> 108, 115 79, 121 diff
>>>> 79, 121 79, 121
>>>> 108, 115 108, 115
>>>> 132, 144 132, 144
>>>> 147, 146 146, 146 (diff negative size means no highlight)
>>>> 146, 146 146, 146
>>>> 79, 121 79, 121
>>>> 108, 115 108, 115
>>>> 132, 144 132, 144
>>>> 147, 146 146, 146
>>>> 146, 146 146, 146
>>>> 79, 121 79, 121
>>>> 108, 115 108, 115
>>>> 132, 144 132, 144
>>>> 147, 146 146, 146
>>>> 146, 146 146, 146
>>>> 79, 121 79, 121
>>>> 108, 115 108, 115
>>>> etc...
>>>> For example the first difference is because Pharo shows the whole
>>>> assignment
>>>> of the first line as the first send, even though it is not.
>>>> The second difference is that Pharo shows the assignment inside the block
>>>> as
>>>> the first highlight of the loop even though the to:do should be
>>>> highlighted....but both Pharo & Squeak get the to:do: wrong when they
>>>> choose
>>>> to show it.
>>>> hope you get the idea...
>>>> Mike
>>>
>>
>>
>>
>
