March 2017 - Pharo-users - lists.pharo.org

Re: [Pharo-users] What is the craziest bug you ever face

by Brenda Larcom

When I was developing a new Morphic layout policy (in Squeak before there was Pharo, but I imagine it still applies), I found numerous bugs relating to bounds and layout methods and the order they get called in various circumstances; bounds & layout is a poorly documented, fragile part of Morphic. It was a long time ago, so I have forgotten the details, but periodically, something I wrote for my layout would add or trigger one of these bugs, the entire GUI would stop working, and I would be left with the emergency debugger. I didn't & probably don't have enough skill with the emergency debugger to debug order & layout issues in objects I can no longer see, so I would roll back my latest change & keep working blind, trying to guess what went wrong. Of course if you get the emergency debugger, you can't see anything that was in the Transcript either. I vaguely recall making a lot faster progress after finding a way to put a conditional halt in the layout methods, so more of the time, I could have only that object be messed up while I stepped through what was happening. I don't know about concepts, but two actual tools that might have helped (and for all I know, existed but I didn't/don't know about them): - Some kind of sandbox like projects, where changes apply to some subset of objects first, before you roll them out to all objects. But, to help in this case, it would have to allow display of objects from multiple "projects" in the same world, so that the debugger would still work if bounds calculations were messed up for the test objects. - A message passing visualizer that could show an animation of a conversation log among collaborating objects. You could give it a couple of objects and classes to start with, and it could show instance variables that are likely to indicate relationships as well as a sequence of messages that were passed. To see what you wanted, you could hide specific messages, or unhide specific messages, or zoom in on a specific moment. It's changing the topic a little (since dealing with security bugs is part of what I do, they aren't difficult or unusual for me), but from a security perspective, it seems to be difficult for developers to understand and (for Smalltalk developers especially) believe the security bugs they write. These bugs may not result in functionality problems until the code is attacked. It would be good for the community if we had a visual taint tracker. This could help people see injection vulnerabilities, which seem to be the most often disbelieved. When you inspect an object, you could see e.g. which data came directly from the network. To change the data from red to green, you would need to validate it in some way, or (dangerously) mark data sources as trusted. We would need a taint tracking infrastructure to make this possible, so it would be a substantial project, but e.g. perl (of all languages) has had that part for 20 years. Telling a tool where you think your validation perimeter is, or which instance variables you are trusting, would be especially neat, since if you saw tainted data inside that perimeter, you would know you had a problem. Ah, so easy to wave ideas around, so much more work to actually implement them. :/ Brenda > On Mar 9, 2017, at 5:36 AM, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: > > Hi guys > > During the DSU workshop we were brainstorming about what are the most difficult bugs we faced and what are the conceptual tools that would have helped you. > > Stef

March 14, 2017

programmatic use of the language compiler

by Raffaello Giulietti

Hi, I'm wondering how to programmatically compile a method. I tried using a variant of ClassDescription>>compile:*:notifying: However, on a method with undeclared variables, when the Transcript is open there seems to be no way to avoid a message being written there. Further, the requestor passed as a notifier in the above method is not even notified when the compilation context is not interactive. What is the correct way to use the compiler programmatically and in a non interactive batch, still being able to catch all the compilation errors and warnings? Thanks Raffaello

March 14, 2017

Re: [Pharo-users] snap package can't find vm-display-X11

by Alistair Grant

On 14 March 2017 at 10:32, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > >> On 14 Mar 2017, at 08:50, Alistair Grant <akgrant0710(a)gmail.com> wrote: >> >> On 13 March 2017 at 17:43, Alistair Grant <akgrant0710(a)gmail.com> wrote: >>> Hi Guillermo, >>> ... >>> >>> Cairo isn't working yet. It looks like CairoLibrary makes assumptions >>> about the location of libcairo.so. I'm in the middle of fixing that >>> at the moment. >> >> I've submitted SLICE-Issue-19833-CairoLibrary-unix-module-location-assumptions-too-restrictive >> which resolves the path lookup, so Cairo is now working inside the >> snap package. > > Well done, I saw you struggled a bit with the CI infrastructure, but you persevered. Thanks. I also struggled a lot with fuzzy-headed thinking :-) Cheers, Alistair

March 14, 2017

Re: [Pharo-users] [Pharo-dev] Mini Pharo -> JavaScript translator?

by H. Hirzel

You mean this one (attached)? How would I use it standalone to translate Smalltalk to JavaScript? --Hannes On 3/14/17, H. Hirzel <hannes.hirzel(a)gmail.com> wrote: > Hi Dave, > > I was looking for the class you mention, JSCodeGenerator in the > VMMaker repository, but I did not find it. > > Where do I need to go? > > Regards > > --Hannes > > On 3/11/17, David T. Lewis <lewis(a)mail.msen.com> wrote: >> On Sat, Mar 11, 2017 at 06:16:26AM +0100, H. Hirzel wrote: >>> On 3/10/17, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: >>> > Hi! >>> > >>> > Is there a simple way to translate Pharo code into Javascript? >>> > There is Pharo JS, but I cannot load it in Pharo 6. There is the amber >>> > compiler, but I cannot find a version for Pharo. >>> > >>> > Amber takes the approach of translating everything into JavaScript, >>> > including the Smalltalk object model. While this is great for fan of >>> > bootstrapping images, it produces large javascript code. >>> > >>> > Is there a kind of Slang for JavaScript? I am looking for something >>> > minimal. >>> > >>> > Cheers, >>> > Alexandre >>> >>> >>> Hello Alexandre >>> >>> >>> Something like this >>> https://github.com/ympbyc/LittleSmallscript >>> >>> or >>> >>> >>> http://wiki.squeak.org/squeak/5860 which refers to >>> http://www.squeaksource.com/@xxu3r2Ma7SbqJi3E/1j-SgMCf (74000 >>> downloads). >>> >>> People have used it successfully. >>> >>> There is probably a Pharo port. >>> >> >> There is also an actual Slang code generator for Javascript, written >> by Bert Freudenburg and used to generated the VM plugins for the >> SqueakJS VM. You can find it in the VMMaker package (not VMMaker.oscog) >> at http://source.squeak.org/VMMaker, see class JSCodeGenerator. >> >> Dave >> >> >> >

March 14, 2017

Re: [Pharo-users] [Pharo-dev] Mini Pharo -> JavaScript translator?

by H. Hirzel

Hi Dave, I was looking for the class you mention, JSCodeGenerator in the VMMaker repository, but I did not find it. Where do I need to go? Regards --Hannes On 3/11/17, David T. Lewis <lewis(a)mail.msen.com> wrote: > On Sat, Mar 11, 2017 at 06:16:26AM +0100, H. Hirzel wrote: >> On 3/10/17, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: >> > Hi! >> > >> > Is there a simple way to translate Pharo code into Javascript? >> > There is Pharo JS, but I cannot load it in Pharo 6. There is the amber >> > compiler, but I cannot find a version for Pharo. >> > >> > Amber takes the approach of translating everything into JavaScript, >> > including the Smalltalk object model. While this is great for fan of >> > bootstrapping images, it produces large javascript code. >> > >> > Is there a kind of Slang for JavaScript? I am looking for something >> > minimal. >> > >> > Cheers, >> > Alexandre >> >> >> Hello Alexandre >> >> >> Something like this >> https://github.com/ympbyc/LittleSmallscript >> >> or >> >> >> http://wiki.squeak.org/squeak/5860 which refers to >> http://www.squeaksource.com/@xxu3r2Ma7SbqJi3E/1j-SgMCf (74000 >> downloads). >> >> People have used it successfully. >> >> There is probably a Pharo port. >> > > There is also an actual Slang code generator for Javascript, written > by Bert Freudenburg and used to generated the VM plugins for the > SqueakJS VM. You can find it in the VMMaker package (not VMMaker.oscog) > at http://source.squeak.org/VMMaker, see class JSCodeGenerator. > > Dave > > >

March 14, 2017

Re: [Pharo-users] snap package can't find vm-display-X11

by Sven Van Caekenberghe

> On 14 Mar 2017, at 08:50, Alistair Grant <akgrant0710(a)gmail.com> wrote: > > On 13 March 2017 at 17:43, Alistair Grant <akgrant0710(a)gmail.com> wrote: >> Hi Guillermo, >> ... >> >> Cairo isn't working yet. It looks like CairoLibrary makes assumptions >> about the location of libcairo.so. I'm in the middle of fixing that >> at the moment. > > I've submitted SLICE-Issue-19833-CairoLibrary-unix-module-location-assumptions-too-restrictive > which resolves the path lookup, so Cairo is now working inside the > snap package. Well done, I saw you struggled a bit with the CI infrastructure, but you persevered. > Cheers, > Alistair >

March 14, 2017

Re: [Pharo-users] snap package can't find vm-display-X11

by Alistair Grant

On 13 March 2017 at 17:43, Alistair Grant <akgrant0710(a)gmail.com> wrote: > Hi Guillermo, > ... > > Cairo isn't working yet. It looks like CairoLibrary makes assumptions > about the location of libcairo.so. I'm in the middle of fixing that > at the moment. I've submitted SLICE-Issue-19833-CairoLibrary-unix-module-location-assumptions-too-restrictive which resolves the path lookup, so Cairo is now working inside the snap package. Cheers, Alistair

March 14, 2017

Re: [Pharo-users] What is the craziest bug you ever face

by Richard Sargent

This is not so much about debugging; it's a much more general issue. Given that Smalltalk is designed to allow one to interact with objects, it always frustrates me when our many browsers hide their implementation. We should be able to open inspectors on the model and the UI instance quickly and easily. These would greatly facilitate learning how the browsers works and to be able to script things that the browser developer did not include. e.g. How many methods am I looking at in this method browser? e.g. I want to open a new method browser on a subset of the methods I am looking at. (The rewrite tool helps when the criteria are syntax-based, but ...) and many more things. _____ From: Pharo-users [mailto:pharo-users-bounces@lists.pharo.org] On Behalf Of Stephane Ducasse Sent: March 9, 2017 03:37 To: Any question about pharo is welcome; Pharo Development List Subject: [Pharo-users] What is the craziest bug you ever face Hi guys During the DSU workshop we were brainstorming about what are the most difficult bugs we faced and what are the conceptual tools that would have helped you. Stef

March 14, 2017

Re: [Pharo-users] [Pharo-dev] What is the craziest bug you ever face

by Benoit St-Jean

My worst bug(s) is(are) related to the TopLink ORM. In one particular case, we were working on a *huge* system and different "modules" were assigned to different teams.Â Every module was working perfectly by itself (as confirmed by the SUnit testing) but sometimes, the database would get out of whack. I finally realized that depending on the classes you used to perform object deletion (we had a parent-children-familymembers kinda model), none of the "modules" did it the same way and they all differed when it came to access the to-be-deleted object.Â Most classes accessed the same "kind" of object from a single access point but not all of them!Â That did create interesting problems where the to-be-deleted object reappeared in the database with old values, or just vanished during some operation only to reappear afterwards...Â Besides, debugging proxies and cached objects is a real pain in the *ss !Â And in many cases, you can't ever log properly anything as it would instantiate the proxies!Â So I ended up not trusting the Smalltalk side of things and worked my way out from DB/2 logging only! Â Â ----------------- BenoÃ®t St-Jean Yahoo! Messenger: bstjean Twitter: @BenLeChialeux Pinterest: benoitstjean Instagram: Chef_Benito IRC: lamneth Blogue: endormitoire.wordpress.com "A standpoint is an intellectual horizon of radius zero".Â (A. Einstein)

March 14, 2017

Re: [Pharo-users] [Moose-dev] Re: Roassal IdentityGroup regression?

by Peter Uhnak

Thanks! Peter On Mon, Mar 13, 2017 at 07:20:04PM -0300, Alexandre Bergel wrote: > Hi Peter! > > No idea why this code was removed. > The class is back now. > > Alexandre > > > On Mar 13, 2017, at 6:58 PM, Peter Uhnak <i.uhnak(a)gmail.com> wrote: > > > > Hi, > > > > apparently there used to be RTIdentityGroup (and Collection>>asIdentityGroup) in Rossal, but I can't find any mention of it > > http://forum.world.st/AST-visualization-with-Roassal-td4840243.html > > > > did it vanish on its own (bug) or was that a deliberate choice (feature)? > > > > Peter > > > > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > _______________________________________________ > Moose-dev mailing list > Moose-dev(a)list.inf.unibe.ch > https://www.list.inf.unibe.ch/listinfo/moose-dev

March 13, 2017