Some bugs

Even if you have a AST debugger you still need at some point a bytecode to AST (or source) mapping, because otherwise you cannot just break into a debugger at a random point in the code. I imagine this jump from bytecode to AST interpretation quite difficult; likely you still need a full bytecode stepper to find a position where you can jump into the AST interpreter.

Lukas

On Monday, 5 September 2011, Stéphane Ducasse <[hidden email]> wrote:
> We were thinking with marcus that using byte code to go back to sources code is
> broken by essence and that using an AST is the way to go.
> Now we would need a good AST-based interpreter to start with.
>
>> 2011/9/5 Stéphane Ducasse <[hidden email]>:
>>> BTW mike roberts is building a tool to be able to understand and fix the code range of the debugger hilighting.
>>> Probably your bug is also related to the closure introduction.
>>>
>>> Now the abstraction used is so low level that this is a pain and fragile.
>>> Ideally using an AST would be much better but this is for the future.
>>>
>>> Stef
>>>
>>
>> Stef,
>> If you are saying that implementation is not crystal clear, I can only
>> agree with you.
>> Eliot did avoid a full rewrite (I guess he took the shortest path to
>> make the available implementation work with closures), and this design
>> decision can be questioned indeed.
>>
>> But speaking of abstraction level by itself, I don't understand your sentence.
>> To me, the abstraction is at the correct level.
>> The Debugger has to map the low level execution machinery
>> (Context/program counter/CompiledMethod/byteCodes) to high level
>> specification visible to the user (source code).
>> The Debugger does so by mapping bytecodes to source ranges via AST, no
>> more, no less.
>>
>> In case of inlined blocks, there are more instructions on the bytecode
>> side than messages sent on the AST side, just to make the problem a
>> bit more complex, so maybe there are more intelligent way to address
>> the mapping problem (maybe you mean via an intermediate transformation
>> of AST), but you'll have to explain this a bit deeper.
>>
>> Nicolas
>>
>>>
>>> On Sep 5, 2011, at 9:07 AM, Andrea Brühlmann wrote:
>>>
>>>> Hello Stef,
>>>>
>>>> I appreciate the work of the pharo community! We will continue reporting bugs and submit fixes that
>>>> we made. Of course I do not expect anyone to fix all reported bugs, but there are issues like 4694
>>>> (debugger) where we really need your help. Other issues like the buggy code completion can be
>>>> workarounded by me by disabling code completion ;-)
>>>>
>>>> So thanks for the welcome and I am looking forward to having 4694 fixed!
>>>>
>>>> Andrea
>>>>
>>>>
>>>>
>>>>
>>>> Stéphane Ducasse schrieb:
>>>>> Thanks andrea
>>>>> Welcome to the pharo mailing-list and community. Now I think that this is important that inside netstyle you also consider that if pharo is important for you (which I imagine) that you should also contribute. Bug reporting is already a contribution.  Pharo is an open-source software mainly supported by the free time of people, people that are often do not earning their money from their pharo work (I thank them for all that). I also understand that people can get frustrated by changes but what can we do?
>>>>> May be people can gather and check the fixes that are important to fix but we do not have the force to maintain.
>>>>> Imagine well that we have one engineer full time since 8 months. Stef
>>>>> On Aug 23, 2011, at 8:54 AM, Andrea Brühlmann wrote:
>>>>>> Hello,
>>>>>>
>>>>>> I reported some bugs on the issue tracker and hope you can help me with them!
>>>>>>
>>>>>>
>>>>>> 4681: Accepting with the enter key does not work
>>>>>>     http://code.google.com/p/pharo/issues/detail?id=4681
>>>>>>
>>>>>> 4682: Code completion makes strange cursor placements and too many spaces
>>>>>>     http://code.google.com/p/pharo/issues/detail?id=4682
>>>>>>
>>>>>> 4683: Code completion breaks some search fields (errors during typing)
>>>>>>     http://code.google.com/p/pharo/issues/detail?id=4683
>>>>>>
>>>>>> 4684: Missing ctrl+w (methodNamesContainingIt:)
>>>>>>     http://code.google.com/p/pharo/issues/detail?id=4684
>>>>>>
>>>>>> 4685: Merge dialog: cannot resolve conflict with removed method
>>>>>

--

Lukas Renggli
www.lukas-renggli.ch

Hi Eliot,

Nicolas' change that we put on the tracker didn't really work as
intended (Nicolas did you see that?), but i'll let him respond to the
points he was making.

For me (point #1) It would be better for you to try and tell us the
classes/methods that are either obviously broken or need the attention
to get to a series of fixes.

e.g., ignoring the loop highlight for the moment, the pc mapping goes
wrong right at the start of this example:

toDoOutsideTemp
       | temp collection |
       collection := OrderedCollection new.
       1 to: 5 do: [ :index |
               temp := index.

               collection add: [ temp ] ].

by highlighting pc=2 (IIRC) which is the assignment, but the first
highlight should be pc=3 which is the send of #new. It doesn't
correctly map/avoid the extra instructions for the array
initialisation for copying the values outside the block. is it
possible to fix that first? where do we look?

I am just wondering how this can be approached in stages if possible.
i know it is all related at some level.  stepping into the code/method
that does the majority of the pc mapping is a funny experience ;-)
because the method is structured in such a way to expose a number of
these bugs.

for point #2 ideally we would not ask for a step and have nothing
happen. However i wonder if we can get the highlight areas correct,
even if we have to "step" through hidden parts. This assumes we can
suppress the highlight for the hidden bits which i think we already
have...but only if we can do one without the other.  I would then
write tests for the highlights, and we would have some protection for
further changes.

thanks,
Mike

On Mon, Sep 5, 2011 at 5:14 PM, Eliot Miranda <[hidden email]> wrote:
> Hi Nicolas,
>     that's quite a lot to absorb.  Exactly what do you want me to review?
>  The first thing it seems to me is to define what we want to be highlighted
> at different bytecodes in an optimized loop.  A second thing is to think
> about how the debugger can avoid stepping through the hidden sends that are
> part of a loop.  What I mean is that
>     1 to: n do: [:i| ....]
> is actually
>      i := 1.
>      [i <= n] whileTrue: [
> and so the debugger steps through i:= 1 and i <= n, even though these aren't
> visible in the source.  That's why one has to click several times to get
> into the body of the loop.  The debugger could for example use the source
> ranges for the bytecodes to step until the source range changes.  So if
> there is the same source range info for all the bytecodes involved in the
> loop iteration (not the loop body) the debugger will be able to respond to
> step properly.  What do you think?
>
> [sorry for not having responded sooner; esug and personal issues have got in
> the way. apologies]
> On Thu, Aug 25, 2011 at 1:06 PM, Nicolas Cellier
> <[hidden email]> wrote:
>>
>> 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 <[hidden email]>:
>> > 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 <[hidden email]>:
>> >>>
>> >>>>
>> >>>> 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
>> >>
>> >
>> >
>> >
>>
>
>
>
> --
> best,
> Eliot
>

On Tue, Sep 6, 2011 at 2:10 PM, Michael Roberts <[hidden email]> wrote:

Hi Eliot,

Nicolas' change that we put on the tracker didn't really work as
intended (Nicolas did you see that?), but i'll let him respond to the
points he was making.

For me (point #1) It would be better for you to try and tell us the
classes/methods that are either obviously broken or need the attention
to get to a series of fixes.

e.g., ignoring the loop highlight for the moment, the pc mapping goes
wrong right at the start of this example:

toDoOutsideTemp
       | temp collection |
       collection := OrderedCollection new.
       1 to: 5 do: [ :index |
               temp := index.

               collection add: [ temp ] ].

by highlighting pc=2 (IIRC) which is the assignment, but the first
highlight should be pc=3 which is the send of #new. It doesn't
correctly map/avoid the extra instructions for the array
initialisation for copying the values outside the block. is it
possible to fix that first? where do we look?

Well, this works in Squeak.  The pc ranges must be determined after generating the method *with closure analysis*.  i.e. the code ranges must be derived form the same resulting bytecode.  To derive 2 for the pc of the send of new the system I guess must be compiling for source ranges differently from normal compilation.  Haver you compares Squeak to Pharo for this example?

I am just wondering how this can be approached in stages if possible.
i know it is all related at some level.  stepping into the code/method
that does the majority of the pc mapping is a funny experience ;-)
because the method is structured in such a way to expose a number of
these bugs.

for point #2 ideally we would not ask for a step and have nothing
happen. However i wonder if we can get the highlight areas correct,
even if we have to "step" through hidden parts. This assumes we can
suppress the highlight for the hidden bits which i think we already
have...but only if we can do one without the other.  I would then
write tests for the highlights, and we would have some protection for
further changes.

Right.  First thing is to get the source ranges correct.  Next thing is to modify the debugger so that step has a visible effect, i.e. that the debugger steps until the source range changes.

 

thanks,
Mike

On Mon, Sep 5, 2011 at 5:14 PM, Eliot Miranda <[hidden email]> wrote:
> Hi Nicolas,
>     that's quite a lot to absorb.  Exactly what do you want me to review?
>  The first thing it seems to me is to define what we want to be highlighted
> at different bytecodes in an optimized loop.  A second thing is to think
> about how the debugger can avoid stepping through the hidden sends that are
> part of a loop.  What I mean is that
>     1 to: n do: [:i| ....]
> is actually
>      i := 1.
>      [i <= n] whileTrue: [
> and so the debugger steps through i:= 1 and i <= n, even though these aren't
> visible in the source.  That's why one has to click several times to get
> into the body of the loop.  The debugger could for example use the source
> ranges for the bytecodes to step until the source range changes.  So if
> there is the same source range info for all the bytecodes involved in the
> loop iteration (not the loop body) the debugger will be able to respond to
> step properly.  What do you think?
>
> [sorry for not having responded sooner; esug and personal issues have got in
> the way. apologies]
> On Thu, Aug 25, 2011 at 1:06 PM, Nicolas Cellier
> <[hidden email]> wrote:
>>
>> 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 <[hidden email]>:
>> > 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 <[hidden email]>:
>> >>>
>> >>>>
>> >>>> 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
>> >>
>> >
>> >
>> >
>>
>
>
>
> --
> best,
> Eliot
>

--
best,

Eliot

I checked some of my previously reported bugs in pharo1.3 and added our fixes - thanks for integrating them :-)

Please have a look at the following issues:

New:
4920: Copying a trait fails
4919: Class copying issues

Question:
4688: Progress bar disappears on image save => Does "Milestone-1.4" mean you will not put the fix into 1.3? +

This would be too sad...

Not to forget:

> 4689: MessageTally bug
>     http://code.google.com/p/pharo/issues/detail?id=4689
>

4684: Missing ctrl+w (methodNamesContainingIt:)
   http://code.google.com/p/pharo/issues/detail?id=4684

4686: Method category change creates no new version
   http://code.google.com/p/pharo/issues/detail?id=4686

4692: Drop downs should select the default entry (topmost) instead of a middle one
   http://code.google.com/p/pharo/issues/detail?id=4692

--
Andrea Brühlmann