January 2019 - Pharo-dev - lists.pharo.org

Re: [Pharo-dev] Availability of Smallapack in Pharo6.0

by Denis Kudriashov

Hi Nicolas Ð¿Ñ, 11 ÑÐ½Ð². 2019 Ð³. Ð² 23:34, Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com>: > Hi, > I announce the availability of Smallapack in Pharo6. > > The ConfigurationOfSmallapack is in > http://www.squeaksource.com/MetacelloRepository and there is a copy in > meta repo for Pharo 3/4/5/6. > > Currently, the ported version uses a derivative of OpalCompiler patched to > handle method with 16+ arguments. > External function calls have not been converted yet to UnifiedFFI, but the > patched compiler rather has hook to compile legacy FFI. > Though I did not install the hook to call FFI with more than 15 arguments, > so there is at least 1 unit test failing (but not crashing). > > I have auto-re-generated all the source code for using UnifiedFFI formats, > so the dependency on legacy FFI is not a necessity (apart for simplifying > cross dialect maintenance). > > But I want to review the generated code method by method rather than > filing it in blindly (the wrapper functions are also generated, and I might > loose comments or improvments if I'm careless). Unfortunately, the state of > diff tools in Pharo6, be it thru MC or worse than all, thru legacy change > lists, does not enable such a large scale review, so I think that I will > edit in Squeak and run in Pharo... > > Now that Smallapack supports Opal, there should be no major problem for > porting to Pharo7, but I did not have time to try yet. A few more MC > regressions, and the fact to forbid protocol beginning with a * was too > serious a cross compatibility hurdle for me. > Protocol with star is still convention to store class extensions in files. No compatibility issues here. Calypso just hides it from user because package and protocol is not the same thing. And I hope in Pharo 8 we will support multiple protocols and separate packaging. But more important is to finely clean RPackage implementation. The current way how method is became bound to package is horrible. > But I'll come back to it, tools are generally better in ph7 than ph6. Stay > tuned. > >

Jan. 12, 2019

Re: [Pharo-dev] DebugSession>>activePC:

by Denis Kudriashov

Hi guys. Funny thing that DebugSession does not exists in Squeak. It was introduced in Pharo to represent the model for debugger. Ð¿Ñ, 11 ÑÐ½Ð². 2019 Ð³. Ð² 22:34, Thomas Dupriez via Pharo-dev < pharo-dev(a)lists.pharo.org>: > Yeah, it's a bit unfortunate you assumed I wanted to remove the method. > It brought up a not so pleasant discussion. > Everyone makes mistakes. :-) > > So if I understand, this method gives the pc that maps to the ast node > the debugger should highlight when a context is selected in the stack > widget? If I'm right, how comes that this method has no senders in the > debugger code? That would mean this feature is also implemented > somewhere else. > > Thomas > > Le 11/01/2019 Ã 20:28, Eliot Miranda a Ã©crit : > > Hi Thomas, > > > > forgive me, my first response was too terse. Having thought about it > in the shower it becomes clear :-) > > > >> On Jan 11, 2019, at 6:49 AM, Thomas Dupriez < > tdupriez(a)ens-paris-saclay.fr> wrote: > >> > >> Hi, > >> > >> Yes, my question was just of the form: "Hey there's this method in > DebugSession. What is it doing? What's the intention behind it? Does > someone know?". There was no hidden agenda behind it. > >> > >> @Eliot > >> > >> After taking another look at this method, there's something I don't > understand: > >> > >> activePC: aContext > >> ^ (self isLatestContext: aContext) > >> ifTrue: [ interruptedContext pc ] > >> ifFalse: [ self previousPC: aContext ] > >> > >> isLatestContext: checks whether its argument is the suspended context > (the context at the top of the stack of the interrupted process). And if > that's true, activePC: returns the pc of **interruptedContext**, not of the > suspended context. These two contexts are different when the debugger opens > on an exception, so this method is potentially returning a pc for another > context than its argument... > >> > >> Another question I have to improve the comment for this method is: > what's the high-level meaning of this concept of "activePC". You gave the > formal definition, but what's the point of defining this so to speak? What > makes this concept interesting enough to warrant defining it and giving it > a name? > > There are two âmodesâ where a pc us mapped to a source range. One is > when stepping a context in the debugger (the context is on top and is > actively executing bytecodes). Here the debugger stops immediately before > a send or assignment or return, so that for sends we can do into or over, > or for assignments or returns check stack top to see what will be assigned > or returned. In this mode we want the pc of the send, assign or return to > map to the source range for the send, or the expression being assigned or > returned. Since this is the âcommon caseâ, and since this is the only > choice that makes sense for assignments ta and returns, the bytecode > compiler constructs itâs pc to source range map in terms of the pc of the > first byte if the send, assign or return bytecode. > > > > The second âmodeâ is when selecting a context below the top context. > The pc for any context below the top context will be the return pc for a > send, because the send has already happened. The compiler could choose to > map this pc to the send, but it would not match what works for the common > case. Another choice would appear be to have two map entries, one for the > send and one for the return pc, both mapping to the source range. But this > wouldnât work because the result of a send might be assigned or returned > and so there is a potential conflict. I stead the reasonable solution is > to select the previous pc for contexts below the top of context, which will > be the pc for the start of the send bytecode. > > > > HTH > > > >> Cheers, > >> Thomas > >> > >>> On 11/01/2019 13:53, Tudor Girba wrote: > >>> Hi, > >>> > >>> @Eliot: Thanks for the clarifying answer. > >>> > >>> I believe you might have jumped to conclusion about the intention of > the question. Thomas asked a legitimate question. Without users of a method > it is hard to understand its use. It does not necessarily imply that the > intention is to remove it, but it does show that someone wants to > understand. > >>> > >>> As far as I know, Thomas actually wants to write a test to cover that > usage. I am sure that you appreciate and encourage that :). > >>> > >>> @Thomas: Thanks for this effort! > >>> > >>> Cheers, > >>> Doru > >>> > >>> > >>>> On Jan 10, 2019, at 3:11 PM, Eliot Miranda <eliot.miranda(a)gmail.com> > wrote: > >>>> > >>>> Hi Thomas, > >>>> > >>>>> On Jan 10, 2019, at 2:24 AM, Thomas Dupriez via Pharo-dev < > pharo-dev(a)lists.pharo.org> wrote: > >>>>> > >>>>> <mime-attachment> > >>>> in a stack of contexts the active pc is different for the top > context. For other than the top context, a contextâs pc will be pointing > after the send that created the context above it, so to find the pc of the > send one finds the previous pc. For the top context its pc is the active > pc. > >>>> > >>>> Typically the debugger is invoked in two different modes, > interruption or exception. When interrupted, a process is stopped at the > next suspension point (method entry or backward branch) and the top context > in the process is the context to be displayed in the debugger. When an > exception occurs the exception search machinery will find the signaling > context, the context that raised the exception, which will be below the > search machinery and the debugger invocation above that. The active pc of > the signaling context will be the of for the send of digbsl et al. > >>>> > >>>> So the distinction is important and the utility method is probably > useful. > >>>> > >>>> Do you want to remove the method simply because there are no senders > in the image? > >>>> > >>>> If so, this is indicative of a serious problem with the Pharo > development process. In the summer I ported VMMaker.oscog to Pharo 6. Now > as feenk try and build a VMMaker.oscog image on Pharo 7, the system is > broken, in part because of depreciations and in part because useful methods > (isOptimisedBlock (isOptimizedBlock?) in the Opal compiler) have been > removed. > >>>> > >>>> Just because a method is not in the image does not imply it is not in > use. It simply means that it is not in use in the base image. As the > system gets modularised this issue will only increase. There are lots of > collection methods that exist as a library that are not used in the base > image and removing them would clearly damage the library for users. This > is the case for lots of so-called system code. There are users out there, > like those of us in the vm team, who rely on such system code, and it is > extremely unsettling and frustrating to have that system code change all > the time. If Pharo is to be a useful platform to the vm team it has to be > more stable. > >>> -- > >>> www.feenk.com > >>> > >>> âThe smaller and more pervasive the hardware becomes, the more > physical the software gets." > >>> > >>> > >

Jan. 12, 2019

Re: [Pharo-dev] Availability of Smallapack in Pharo6.0

by Tudor Girba

Hi Nicolas, Very nice! Itâs great to have a fast library for linear algebra. Cheers, Doru > On Jan 12, 2019, at 12:33 AM, Nicolas Cellier <nicolas.cellier.aka.nice(a)gmail.com> wrote: > > Hi, > I announce the availability of Smallapack in Pharo6. > > The ConfigurationOfSmallapack is in http://www.squeaksource.com/MetacelloRepository and there is a copy in meta repo for Pharo 3/4/5/6. > > Currently, the ported version uses a derivative of OpalCompiler patched to handle method with 16+ arguments. > External function calls have not been converted yet to UnifiedFFI, but the patched compiler rather has hook to compile legacy FFI. > Though I did not install the hook to call FFI with more than 15 arguments, so there is at least 1 unit test failing (but not crashing). > > I have auto-re-generated all the source code for using UnifiedFFI formats, so the dependency on legacy FFI is not a necessity (apart for simplifying cross dialect maintenance). > > But I want to review the generated code method by method rather than filing it in blindly (the wrapper functions are also generated, and I might loose comments or improvments if I'm careless). Unfortunately, the state of diff tools in Pharo6, be it thru MC or worse than all, thru legacy change lists, does not enable such a large scale review, so I think that I will edit in Squeak and run in Pharo... > > Now that Smallapack supports Opal, there should be no major problem for porting to Pharo7, but I did not have time to try yet. A few more MC regressions, and the fact to forbid protocol beginning with a * was too serious a cross compatibility hurdle for me. But I'll come back to it, tools are generally better in ph7 than ph6. Stay tuned. > -- www.feenk.com âProgramming is executable philosophy."

Jan. 12, 2019

Re: [Pharo-dev] Is metacello aware of MC branches???

by Cyril Ferlicot

On Fri 11 Jan 2019 at 22:51, Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com> wrote: > Thanks, > that did not work, but I think my mistake was to write this; > > spec for: #'pharo6.0.x' > > instead of: > > spec for: #'pharo6.x'. > > Smalltalk version -> 'Pharo6.0', so probably the second dot does not match > anything... > I'll have to review more ConfigurationOf... > >> Hello, I do not have an image to check but you can find compatible by executing something like `Smalltalk metacelloPlatformAttributes` in a Pharo 6 image. >From what I wrote here: https://github.com/pharo-open-documentation/pharo-wiki/blob/master/General/… I guess your problem is that you tried to load the code in Pharo 6.1 and not 6.0. >>> -- Cyril Ferlicot https://ferlicot.fr

Jan. 12, 2019

Availability of Smallapack in Pharo6.0

by Nicolas Cellier

Hi, I announce the availability of Smallapack in Pharo6. The ConfigurationOfSmallapack is in http://www.squeaksource.com/MetacelloRepository and there is a copy in meta repo for Pharo 3/4/5/6. Currently, the ported version uses a derivative of OpalCompiler patched to handle method with 16+ arguments. External function calls have not been converted yet to UnifiedFFI, but the patched compiler rather has hook to compile legacy FFI. Though I did not install the hook to call FFI with more than 15 arguments, so there is at least 1 unit test failing (but not crashing). I have auto-re-generated all the source code for using UnifiedFFI formats, so the dependency on legacy FFI is not a necessity (apart for simplifying cross dialect maintenance). But I want to review the generated code method by method rather than filing it in blindly (the wrapper functions are also generated, and I might loose comments or improvments if I'm careless). Unfortunately, the state of diff tools in Pharo6, be it thru MC or worse than all, thru legacy change lists, does not enable such a large scale review, so I think that I will edit in Squeak and run in Pharo... Now that Smallapack supports Opal, there should be no major problem for porting to Pharo7, but I did not have time to try yet. A few more MC regressions, and the fact to forbid protocol beginning with a * was too serious a cross compatibility hurdle for me. But I'll come back to it, tools are generally better in ph7 than ph6. Stay tuned.

Jan. 11, 2019

Visual Studio code Configuration for the VM

by Guillermo Polito

Hi guys, We have been using this week with Pablo a combination of Visual Studio Code, cygwin, and gdb to build and debug the VM to chase some issues during ffi calls in win64. It was overall simple to setup, and though I thought it was going to be just a text editor with vitamines, it ended up being a really light but versatile IDE with code navigation, compilation and debugging integration. But, since there were some little things over here and there like gdb source code mapping that was not so straight forward to find in the documentation, we thought it would be good to share it. If somebody is interested in using a similar setup to work with the VM, I've left my configuration files in the following gist, including: - cygwin bash terminal integration (also with zsh, but that's pure cygwin) - task actions to build cog and stack vms on debug mode - launch configs to run both in debug mode with gdb attached https://gist.github.com/guillep/452a9be3d231db6f89dd40bfb8cf4405 Cheers, Guille & Pablo

Jan. 11, 2019

Re: [Pharo-dev] Is metacello aware of MC branches???

by Nicolas Cellier

Thanks, that did not work, but I think my mistake was to write this; spec for: #'pharo6.0.x' instead of: spec for: #'pharo6.x'. Smalltalk version -> 'Pharo6.0', so probably the second dot does not match anything... I'll have to review more ConfigurationOf... Le ven. 11 janv. 2019 Ã 21:51, Andrei Chis <chisvasileandrei(a)gmail.com> a Ã©crit : > Hi, > > Would something like this work: > > spec for: #'pharo6.0.x' do: [ > spec package: 'Smallapack-StdLib' with: [ > spec > file: 'Smallapack-StdLib.UFFI-nice.1'] > ] > > Or maybe in the baseline you can have: > > spec package: 'Smallapack-StdLib' with: [ > spec > file: 'Smallapack-StdLib.UFFI-nice'] > ] > > > Cheers, > Andrei > > > On Fri, Jan 11, 2019 at 12:19 PM Nicolas Cellier < > nicolas.cellier.aka.nice(a)gmail.com> wrote: > >> Hi all, >> I'm trying to resolve a dialect compatibility problem like this: >> >> I want to load the Squeak and Pharo3 to 5 version depending on FFI >> Smallapack-StdLib-nice.1 >> >> For Pharo6, I made a different branch depending on UFFI >> Smallapack-StdLib.UFFI-nice.1 >> >> In the base line, i tell >> spec for: #'common' do: [ >> spec blessing: #'baseline'. >> spec repository: 'http://www.squeaksource.com/Smallapack'. >> spec package: 'Smallapack-StdLib'] >> and in the version I tell >> >> spec for: #squeak do: [ >> spec package: 'Smallapack-StdLib' with: >> 'Smallapack-StdLib-nice.1']. >> spec for: #'pharo5.0.x' do: [ >> spec package: 'Smallapack-StdLib' with: >> 'Smallapack-StdLib-nice.1']. >> spec for: #'pharo6.0.x' do: [ >> spec package: 'Smallapack-StdLib' with: >> 'Smallapack-StdLib.UFFI-nice.1']. >> >> but the configuration loads Smallapack-StdLib-nice.1 instead of >> Smallapack-StdLib.UFFI-nice.1 >> >> I would like to avoid using two different package names because it >> complexifies the baseline for nothing. >> It the same package, just a different branch. >> Isn't it possible? >> Why? >> Can we fix it? >> >

Jan. 11, 2019

Re: [Pharo-dev] external#senders (was Re: DebugSession>>activePC:)

by Eliot Miranda

Sven, > On Jan 11, 2019, at 11:40 AM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > > >> On 11 Jan 2019, at 19:32, Eliot Miranda <eliot.miranda(a)gmail.com> wrote: >> >> Sven, >> >>> On Jan 11, 2019, at 10:03 AM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>> >>> Eliot, >>> >>> I can assure you that multiple core Pharo people had the same reaction, don't turn this (again) in a play on one person's emotions (apart from the fact that those are present in all living creatures). >> >> First you assume a motive I donât have. I am not trying to provoke anyone. > > Clearly you are, given the reactions. > > Like Doru said, you did not just answer the question, your last two paragraphs contained lots of provocation. Youâre entitled to your opinion. But since the intent to provoke or not would be in my head youâre is a projection, not fact. > >> Second, I think emotions are the results of mammalian brains, perhaps bird and fish brains, and certainly not present in amoeba. > > First an IS reference, now this: yes, you are a man ratio and reason only, devout of human emotions like the rest of us. Good for you. > > Hundreds of libraries and frameworks were moved between Pharo 6.x and 7, with minimal changes. > > We are an active, living community where many, many people contribute, are allowed to make mistakes, to question old code and old rules, to learn, to make things better. > >>> Sven >>> >>>> On 11 Jan 2019, at 18:57, Eliot Miranda <eliot.miranda(a)gmail.com> wrote: >>>> >>>> Stef, >>>> >>>>> On Jan 10, 2019, at 11:24 PM, ducasse <stepharo(a)netcourrier.com> wrote: >>>>> >>>>> Ben >>>>> >>>>> Since you asked I reply. >>>>> For calypso we try and sometimes fail and retry. But we do not rant. >>>>> >>>>> Now the solution is also to have tests and this is what we are doing. >>>>> We want more tests and we are working on having more tests. >>>>> >>>>> The solution is also to have ***********positive********* communication. >>>>> >>>>> There is no point to piss on our process because >>>>> - we were the first to push package usage back in squeal 3.9 >>>>> - increase enormously the number of tests >>>>> - have CI to run the tests and use PR. >>>>> and it is working! >>>>> >>>>> So before bashing us I would expect a bit of respect that it is due to our track record. >>>> >>>> Again you fail to respond to an attempt to discuss real issues and instead take it as a personal map attack and respond emotionally. Ben is /not/ bashing your process in an attempt to damage Pharo. As an academic researcher you should be able to respond objectively to criticism. This frequent emotionality doesnât help you or the community. >>>> >>>>> >>>>> Finally it takes 1 min to enter a bug entry and now you cannot even complain that you have to log >>>>> because it is on github. (BTW nobdoy is asking the amount of time it takes US to migrate and go over the bug entry - >>>>> again I ask for respect for the people doing this tedious, boring but important job). >>>>> >>>>> When VMMaker will be available in Pharo we will be able to automate things not before. >>>>> Please remember also that Igor paid by us spent a lot of time making sure that >>>>> everybody and in particular our jenkins server could automatically build vm. >>>>> >>>>> So we believe in agility, communication and automation. >>>>> >>>>> Stef >>>>> >>>>> >>>>> >>>>> >>>>>> On 11 Jan 2019, at 05:54, Ben Coman <btc(a)openinworld.com> wrote: >>>>>> >>>>>> On Thu, 10 Jan 2019 at 23:51, ducasse via Pharo-dev <pharo-dev(a)lists.pharo.org> wrote: >>>>>> Thomas can you integrate such comments in the debugger class comment >>>>>> >>>>>> @Eliot thanks for the explanation. >>>>>> About the method removed, could you please react less negatively? It would be nice. >>>>>> I cannot believe that you the guy that know the VM would get stopped to open a bug entry telling us that isOptimizedBlock >>>>>> has been removed and it should not. How much time opening a bug entry can take? Under 1 min I guess. >>>>>> >>>>>> I'd guess it takes more than 1 minute overall - a few minutes to shift context to open an old Pharo image >>>>>> and a few more open the original method to copy it to Pharo and repeat that for the next ten missing methods, >>>>>> and then having fixed it for yourself, rather than just log a job for someone else, having fixed your own >>>>>> you now repair your pharo repo with Iceberg and submit a commit, and your now off-task by half an hour. >>>>>> Not a great deal of time if that was what you schedule to work on, you but frustrating when dragged off task. >>>>>> >>>>>> The thing is, when is someone is frustrated, without sharing there is no chance to resolve anything, >>>>>> so the frustration doubles and builds up, and unconsciously creeps in relationships and/or leads to a breakdown. >>>>>> Putting it out in the world relieves that pressure and provides the possibility that someone might >>>>>> find a middle path. As always, it is not what is said but how it is said, >>>>>> and personally that seemed okay to me. >>>>>> >>>>>>>> Just because a method is not in the image does not imply it is not in use. It simply means that it is not in use in the base image. As the system gets modularised this issue will only increase. >>>>>> >>>>>> On the flip side, if the rule was "don't touch unused methods", that would block a lot of action >>>>>> around cleaning, minimisation and modulation that are important. Even though those things >>>>>> aren't directly the shiney new tools that make Pharo great, its their philosophy that underpins >>>>>> a lot of the visible Pharo improvements which has facilitated Pharo's growth. >>>>>> That "vision" is why I'm here. >>>>>> >>>>>> The pivot point here the concept of "unused" and perhaps where we can do better. >>>>>> Currently developers have no information available to base their decision on. >>>>>> Requiring developers to query the mail list about every cleaning, minimisation and modulation action >>>>>> would have a freezing effect. >>>>>> >>>>>> For stuff that is image its much easier for developers since: >>>>>> * its "visible" right in front of them >>>>>> * they can make decisions and take action around it >>>>>> * tests can be run >>>>>> >>>>>> So the question is how we can get those things for important modules outside the image? >>>>>> For me, VM is not like any third party app but is very much a *part* of Pharo >>>>>> since its something which helps Pharo itself advance. So lets treat it as such, similar >>>>>> to how we treat other modules like Calypso or Iceberg which happen distributed in-Image. >>>>>> Can we consider the last step of the CI (after packing the CI product) >>>>>> could load a static version of VMMaker? Not that any issues would fail the commit, but just report >>>>>> to bring "visibility" to the table ? >>>>>> >>>>>> Or, once VMMaker is in git, perhaps a separate opensmalltalk-vm CI job >>>>>> could run against each latest Pharo image to report problems? >>>>>> >>>>>> Or to broaden the perspective of "unused" further, we could put broader #senders-info in front >>>>>> of developers so then can make informed decisions at design time rather cleaning up after-the-fact? >>>>>> Projects could register on a central site their list of #senders (generated from some tool) >>>>>> so the Pharo IDE could reference that when asked for #senders - so the information is available >>>>>> to make informed decisions. >>>>>> >>>>>> Clicking on an external#sender could pop up the actual code hosted on github, >>>>>> so developers have even better knowledge for decisions and communication. >>>>>> >>>>>> Of course, creating such a system requires effort in our world of limited resources. >>>>>> But the external#senders register could be a premium service available just >>>>>> to Pharo Association/Consortium members which sets up a bit of a win/win scenario. >>>>>> It helps developers and is an incentive to join up. This is not to guarantee changes won't >>>>>> affect your project's #senders, but just to improve communication around them. >>>>>> >>>>>> >>>>>> So why if marcus removed it inadvertently would you want to make him feel bad? I donât want people to feel bad. >>>>>> >>>>>> We can do mistake. >>>>>> >>>>>> That is an important philosophy, but here is a key thing to be clear on... >>>>>> [ "If you are not open to hearing about mistakes, then you are not open to making mistakes." ] repeat. >>>>>> >>>>>> There is no reason for an individual to feel bad about removing an "unused" method if that is the process. >>>>>> But can the process be improved? >>>>>> >>>>>> cheers -ben >>> >>> > >

Jan. 11, 2019

Re: [Pharo-dev] Is metacello aware of MC branches???

by Andrei Chis

Hi, Would something like this work: spec for: #'pharo6.0.x' do: [ spec package: 'Smallapack-StdLib' with: [ spec file: 'Smallapack-StdLib.UFFI-nice.1'] ] Or maybe in the baseline you can have: spec package: 'Smallapack-StdLib' with: [ spec file: 'Smallapack-StdLib.UFFI-nice'] ] Cheers, Andrei On Fri, Jan 11, 2019 at 12:19 PM Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com> wrote: > Hi all, > I'm trying to resolve a dialect compatibility problem like this: > > I want to load the Squeak and Pharo3 to 5 version depending on FFI > Smallapack-StdLib-nice.1 > > For Pharo6, I made a different branch depending on UFFI > Smallapack-StdLib.UFFI-nice.1 > > In the base line, i tell > spec for: #'common' do: [ > spec blessing: #'baseline'. > spec repository: 'http://www.squeaksource.com/Smallapack'. > spec package: 'Smallapack-StdLib'] > and in the version I tell > > spec for: #squeak do: [ > spec package: 'Smallapack-StdLib' with: > 'Smallapack-StdLib-nice.1']. > spec for: #'pharo5.0.x' do: [ > spec package: 'Smallapack-StdLib' with: > 'Smallapack-StdLib-nice.1']. > spec for: #'pharo6.0.x' do: [ > spec package: 'Smallapack-StdLib' with: > 'Smallapack-StdLib.UFFI-nice.1']. > > but the configuration loads Smallapack-StdLib-nice.1 instead of > Smallapack-StdLib.UFFI-nice.1 > > I would like to avoid using two different package names because it > complexifies the baseline for nothing. > It the same package, just a different branch. > Isn't it possible? > Why? > Can we fix it? >

Jan. 11, 2019

Re: [Pharo-dev] DebugSession>>activePC:

by Thomas Dupriez

Yeah, it's a bit unfortunate you assumed I wanted to remove the method. It brought up a not so pleasant discussion. Everyone makes mistakes. :-) So if I understand, this method gives the pc that maps to the ast node the debugger should highlight when a context is selected in the stack widget? If I'm right, how comes that this method has no senders in the debugger code? That would mean this feature is also implemented somewhere else. Thomas Le 11/01/2019 Ã 20:28, Eliot Miranda a Ã©critÂ : > Hi Thomas, > > forgive me, my first response was too terse. Having thought about it in the shower it becomes clear :-) > >> On Jan 11, 2019, at 6:49 AM, Thomas Dupriez <tdupriez(a)ens-paris-saclay.fr> wrote: >> >> Hi, >> >> Yes, my question was just of the form: "Hey there's this method in DebugSession. What is it doing? What's the intention behind it? Does someone know?". There was no hidden agenda behind it. >> >> @Eliot >> >> After taking another look at this method, there's something I don't understand: >> >> activePC: aContext >> ^ (self isLatestContext: aContext) >> ifTrue: [ interruptedContext pc ] >> ifFalse: [ self previousPC: aContext ] >> >> isLatestContext: checks whether its argument is the suspended context (the context at the top of the stack of the interrupted process). And if that's true, activePC: returns the pc of **interruptedContext**, not of the suspended context. These two contexts are different when the debugger opens on an exception, so this method is potentially returning a pc for another context than its argument... >> >> Another question I have to improve the comment for this method is: what's the high-level meaning of this concept of "activePC". You gave the formal definition, but what's the point of defining this so to speak? What makes this concept interesting enough to warrant defining it and giving it a name? > There are two âmodesâ where a pc us mapped to a source range. One is when stepping a context in the debugger (the context is on top and is actively executing bytecodes). Here the debugger stops immediately before a send or assignment or return, so that for sends we can do into or over, or for assignments or returns check stack top to see what will be assigned or returned. In this mode we want the pc of the send, assign or return to map to the source range for the send, or the expression being assigned or returned. Since this is the âcommon caseâ, and since this is the only choice that makes sense for assignments ta and returns, the bytecode compiler constructs itâs pc to source range map in terms of the pc of the first byte if the send, assign or return bytecode. > > The second âmodeâ is when selecting a context below the top context. The pc for any context below the top context will be the return pc for a send, because the send has already happened. The compiler could choose to map this pc to the send, but it would not match what works for the common case. Another choice would appear be to have two map entries, one for the send and one for the return pc, both mapping to the source range. But this wouldnât work because the result of a send might be assigned or returned and so there is a potential conflict. I stead the reasonable solution is to select the previous pc for contexts below the top of context, which will be the pc for the start of the send bytecode. > > HTH > >> Cheers, >> Thomas >> >>> On 11/01/2019 13:53, Tudor Girba wrote: >>> Hi, >>> >>> @Eliot: Thanks for the clarifying answer. >>> >>> I believe you might have jumped to conclusion about the intention of the question. Thomas asked a legitimate question. Without users of a method it is hard to understand its use. It does not necessarily imply that the intention is to remove it, but it does show that someone wants to understand. >>> >>> As far as I know, Thomas actually wants to write a test to cover that usage. I am sure that you appreciate and encourage that :). >>> >>> @Thomas: Thanks for this effort! >>> >>> Cheers, >>> Doru >>> >>> >>>> On Jan 10, 2019, at 3:11 PM, Eliot Miranda <eliot.miranda(a)gmail.com> wrote: >>>> >>>> Hi Thomas, >>>> >>>>> On Jan 10, 2019, at 2:24 AM, Thomas Dupriez via Pharo-dev <pharo-dev(a)lists.pharo.org> wrote: >>>>> >>>>> <mime-attachment> >>>> in a stack of contexts the active pc is different for the top context. For other than the top context, a contextâs pc will be pointing after the send that created the context above it, so to find the pc of the send one finds the previous pc. For the top context its pc is the active pc. >>>> >>>> Typically the debugger is invoked in two different modes, interruption or exception. When interrupted, a process is stopped at the next suspension point (method entry or backward branch) and the top context in the process is the context to be displayed in the debugger. When an exception occurs the exception search machinery will find the signaling context, the context that raised the exception, which will be below the search machinery and the debugger invocation above that. The active pc of the signaling context will be the of for the send of digbsl et al. >>>> >>>> So the distinction is important and the utility method is probably useful. >>>> >>>> Do you want to remove the method simply because there are no senders in the image? >>>> >>>> If so, this is indicative of a serious problem with the Pharo development process. In the summer I ported VMMaker.oscog to Pharo 6. Now as feenk try and build a VMMaker.oscog image on Pharo 7, the system is broken, in part because of depreciations and in part because useful methods (isOptimisedBlock (isOptimizedBlock?) in the Opal compiler) have been removed. >>>> >>>> Just because a method is not in the image does not imply it is not in use. It simply means that it is not in use in the base image. As the system gets modularised this issue will only increase. There are lots of collection methods that exist as a library that are not used in the base image and removing them would clearly damage the library for users. This is the case for lots of so-called system code. There are users out there, like those of us in the vm team, who rely on such system code, and it is extremely unsettling and frustrating to have that system code change all the time. If Pharo is to be a useful platform to the vm team it has to be more stable. >>> -- >>> www.feenk.com >>> >>> âThe smaller and more pervasive the hardware becomes, the more physical the software gets." >>> >>>

Jan. 11, 2019