February 2012 - Pharo-dev - lists.pharo.org

[Pharo-project] Reserve the dates: 24-25

by StÃ©phane Ducasse

Hi guys after compiling all your answers and checking with the local constraints: Rooms and others like free days we will organize the Pharo conference the 24-25 May. We would need some help for setting up a simple web site for registration. Stef

Feb. 9, 2012

[Pharo-project] Enhancement: Browsing SLICE dependencies with tree view in Monticello Repository Inspector

by Ben Coman

I originally thought something was wrong when I could not browse the code of a SLICE using Monticello. After hunting around I found [1] saying this is expected behaviour. However I then suggest the following enhancement: Have the right-pane of the Monticello Repositoy Inspector be a tree view, such that dependencies are the children which can then be <Browsed> together from the one place, rather than having to chase them manually. This seems more intuitive usage, especially for those not familiar with what slices are. (I had to hunt around for 5 minutes to find out) What do you think? cheers, -ben [1] http://code.google.com/p/pharo/issues/detail?id=1606 says " <Browse> in MC only browses the contents of the *selected* package - not of dependent packages. Therefore the slice package always looks empty, because it actually is empty."

Feb. 9, 2012

[Pharo-project] [COTDC] 107 - CommentNode

by sean＠clipperadams.com

106 classes done 537 classes remaining Continuing in Compiler... Today: CommentNode Comment Of The Day Contest - One Day One Comment Rules: #1: Each day a not commented class is elected. Each day the best comment will be integrated with name of the author(s). #2: If you cannot comment it, deprecate it. Results: http://code.google.com/p/pharo/wiki/CommentOfTheDayContest p.s. this message was sent from a pharo image. Did you know you could easily do that?!

Feb. 8, 2012

Re: [Pharo-project] Trusting Trust

by Nicolas Cellier

Yes, so duplicating the Compiler can't be a valid strategy. Every Inspector, every Debugger, every message send will modify the binary image... You could trace the image with another program - or another trusted image ;) - and validate some restrictive invariants, for example like: - all behaviours are accessible thru an environment (Smalltalk globals currently) - all behaviours have a methodDict inst var. which is an instance of MethodDictionary - MethodDictionary allInstances size = all behaviors size - all CompiledMethods instances are installed in a MethodDictionary But I'm quite sure that most of these are already false in our image... ...like I launched a process from within a doIt... Or some block of code are rooted in removed or changed CompiledMethod but are still in use, etc... And even better, i can create and compile code at will, so what would prevent me to hide some nasty byte code in an icon by steganography, uncrypt it with an obscure un-noticed graphics method, or even better, use an existing BitBlt method, there are so many.. I would just have to introduce a small bug to trigger its execution, or nec plus ultra exploit an existing one.... Unless I don't even need a bug: there are enough places to store code into, an innocent MessageSend can easily be triggered by some Morph. and I'm quite sure above attack is doable by simply hacking the background Pharo image ;) Nicolas 2012/2/8 Ben Coman <btc(a)openinworld.com>: > You are right. Â The compiler binary described in the scenario corresponds to > the whole of the Smalltalk binary image. > > > Nicolas Cellier wrote: >> >> Do you really think that the compiler is the real Achille heal in an >> image where everything work by message send? >> IMO, the compiler is much less central than in other languages. >> >> What I would do to fool users and tools would just be to hack a few >> methods like #methodDict (just like Stephane proposed for example). >> I would arrange to not answer the true methodDict but a fake for a few >> classes. >> Create a class var in Behavior, like FakedBehaviors := Dictionary new. >> Then modify Behavior>>methodDict >> Â Â ^FakedBehaviors at: self ifAbsent: [methodDict] >> >> Then you can start populating FakedBehaviors. >> Of course, you would begin by faking Behavior itself to not be caught. >> >> Then you could also arrange to falsify Smalltalk at: >> #MethodDictionary, just to avoid a sneaker to try (MethodDictionary >> allInstances), and let a class var hook in Behavior refer to the >> TrueMethodDictionary etc... fake instVarAt: to never return the true >> methodDict, fake the messages concerning Behavior classPool to hide >> your piracy... Or better, don't use a class var at all, but just hack >> a literal in the hacked method... Faking the whole IDE is a lot more >> work (think of inspectors, debuggers, Object tracing etc..), but >> really is possible, and removing clues is also possible, it's just a >> bootstrap problem ;) >> >> There is no in-image parade, you'd have to use tracing from outside. >> >> Nicolas >> >> 2012/2/8 Ben Coman <btc(a)openinworld.com>: >> >>> >>> Frank Shearar wrote: >>> >>>> >>>> On 8 February 2012 10:33, Norbert Hartl <norbert(a)hartl.name> wrote: >>>> >>>> >>>>> >>>>> Am 08.02.2012 um 11:12 schrieb Philippe Marschall: >>>>> >>>>> >>>>>> >>>>>> On 02/08/2012 10:43 AM, Marcus Denker wrote: >>>>>> >>>>>> >>>>>>> >>>>>>> On Feb 8, 2012, at 10:39 AM, Philippe Marschall wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>>>> >>>>>>>>> well I do not think so since we can all read the code. >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> No, read the argument again. If the compiler is compromised and the >>>>>>>> other tools in the image are compromised you can't read the code >>>>>>>> because the >>>>>>>> tools don't display you the actual code. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> But this stays the same with a boot-strap, as you will use a >>>>>>> compomised >>>>>>> compiler to bootstrap the bootstrap. >>>>>>> >>>>>>> There is nothing you can do against it. It's true for GCC or Java, >>>>>>> too. >>>>>>> >>>>>>> >>>>>> >>>>>> Yes, but read the links on how you can use a different, second >>>>>> compiler. >>>>>> >>>>>> >>>>>> >>>>> >>>>> And what if the second compiler is compromised, too? An operating >>>>> system >>>>> is also a virtual environment. So what if that environment is rooted, >>>>> lives >>>>> in another shell? >>>>> The "what if"-question in a security context can be played infinitely. >>>>> The compromisable areas are only defined in opposite where you have put >>>>> some >>>>> trust. Or saying it in other words: There is no trust until you put it >>>>> somewhere. >>>>> >>>>> Norbert >>>>> >>>>> >>>> >>>> Indeed; that's precisely the point: both compilers need to be >>>> subverted in the SAME way in order for you not to notice. The chances >>>> of that happening are much lower than not anything at all! >>>> Â Regarding "There is no trust until you put it somewhere", my favourite >>>> webcomic (http://www.schlockmercenary.com/) puts it thusly: "A little >>>> trust goes a long way. The less you use, the further you'll go." >>>> >>>> But of course it takes time and effort into removing the trust you've >>>> placed in your compiler. It would not be unreasonable for Pharo to say >>>> "yes, we know that we're trusting the compiler" simply because there >>>> are other, more pressing matters. >>>> >>>> frank >>>> >>>> >>> >>> Security is not an absolute - it is a spectrum. Â My usual example is >>> comparing at one extreme keeping all your savings in shoe boxes under you >>> bed. Â Very simple to use but also easily subverted. Â At the other extreme >>> you keep all your savings behind several bank vault doors under a >>> mountain. >>> Â 'Almost' absolutely secure but not very usable. Â In practice the line is >>> drawn somewhere between by balancing risks, effort and usability. Â It is >>> useful to consider each extreme to help balancing these conflicting >>> priorities. >>> >>> I like the term "practical paranoia." Â Think paranoid to be aware of the >>> issues, then decide based on practical matters what to do about them. >>> The >>> Pharo image is a single binary evolving over more than twenty years. Â At >>> one >>> extreme you implicitly trust _every_ unknown hand that ever had access to >>> the trunk. Â At the other extreme "most" people _are_ good people. Â Pharo >>> certainly has more pressing matters, but the aim should be to reduce the >>> surface area of attack/trust where possible. Â A single bootstrap step >>> without Diverse Double-Compiling goes a long way to achieving this. >>> >>> StÃ©phane Ducasse wrote: >>> >>>> >>>> On Feb 8, 2012, at 9:35 AM, Philippe Marschall wrote: >>>> >>>> >>>> >>>>> >>>>> I think it's worse in Pharo because you're never bootstrapping from >>>>> source. From all you know the tools could be subverted to show you a >>>>> different code than is actually running in the system. >>>>> >>>>> >>>> >>>> well I do not think so since we can all read the code. >>>> If you have a bootstrap in C or assembly it does make me more confident. >>>> >>>> So the argument while nice at first sight does not hold a second. Now we >>>> will get a bootstrapped version of pharo believe me :) >>>> >>>> >>>> >>> >>> That is good to hear. Â My contemplation of this stemmed from seeing the >>> stub >>> for bootstrapping in the PharoVision document. Â This dredged up a memory >>> of >>> reading the articles long ago and was was interested in views of how it >>> applied today. Â While there are a lot of other benefits from >>> bootstrapping, >>> security provides just one more reason to justify the effort. >>> Thanks for your thought, >>> Cheers, -ben >>> >>> >>> >>> >> >> >> >> > > >

Feb. 8, 2012

Re: [Pharo-project] Trusting Trust

by Igor Stasenko

On 8 February 2012 12:33, Norbert Hartl <norbert(a)hartl.name> wrote: > > Am 08.02.2012 um 11:12 schrieb Philippe Marschall: > >> On 02/08/2012 10:43 AM, Marcus Denker wrote: >>> >>> On Feb 8, 2012, at 10:39 AM, Philippe Marschall wrote: >>> >>>>> well I do not think so since we can all read the code. >>>> >>>> No, read the argument again. If the compiler is compromised and the other tools in the image are compromised you can't read the code because the tools don't display you the actual code. >>>> >>> But this stays the same with a boot-strap, as you will use a compomised compiler to bootstrap the bootstrap. >>> >>> There is nothing you can do against it. It's true for GCC or Java, too. >> >> Yes, but read the links on how you can use a different, second compiler. >> > And what if the second compiler is compromised, too? An operating system is also a virtual environment. So what if that environment is rooted, lives in another shell? > The "what if"-question in a security context can be played infinitely. The compromisable areas are only defined in opposite where you have put some trust. Or saying it in other words: There is no trust until you put it somewhere. > +1 -- Best regards, Igor Stasenko.

Feb. 8, 2012

[Pharo-project] Some code

by Schwab,Wilhelm K

Stef, I tried to push this to the inbox, but there was a problem, and "the administrator has been notified." Oh well. Attachments work. Attached are my FFI extensions, including non-aligned (with which I have been able to slide so far???) double arrays, catalog (schema) information for ODBC, value adapters, and some patching around weak collections to make a thread safe and self-cleaning sort of them - essential IMHO. None of this is particularly polished. Some parts are more heavily tested than others. Bill

Feb. 8, 2012

Re: [Pharo-project] Migrating to Gemstone

by Dale Henrichs

That one is not quite as easy:) Dale ----- Original Message ----- | From: "Camillo Bruni" <camillo.bruni(a)inria.fr> | To: Pharo-project(a)lists.gforge.inria.fr | Sent: Wednesday, February 8, 2012 4:03:40 AM | Subject: Re: [Pharo-project] Migrating to Gemstone | | Well the main thing here is that I still have to manually create the | project on gemstone :P | | | On 2012-02-07, at 20:55, Dale Henrichs wrote: | | > Ben, | > | > I think that Mariano describes what you are looking for[1] | > | > [1] | > http://marianopeck.wordpress.com/2011/11/08/migrating-projects-to-squeaksou… | > | > ----- Original Message ----- | > | From: "Benjamin" <benjamin.vanryseghem.pharo(a)gmail.com> | > | To: Pharo-project(a)lists.gforge.inria.fr | > | Sent: Tuesday, February 7, 2012 11:29:56 AM | > | Subject: [Pharo-project] Migrating to Gemstone | > | | > | Would it be possible to write some kind of import / migrate | > | script | > | for ss3.gemstone.com ? | > | | > | The following lines copy the complete version history to an | > | *existing* project on gemstone: | > | | > | Gofer new | > | url: 'http:/squeaksource.com/FOO'; | > | package: 'FOO'; package: 'BAR'; ... | > | url: 'http://ss3.gemstone.com/ss/FOO'; | > | push | > | | > | but that still requires me to define all packages I want to | > | import | > | *and* to create a new | > | project on gemstone.... | > | | > | I would really love to see a one-click experience here? | > | | > | best | > | ben & cami | > | | |

Feb. 8, 2012

Re: [Pharo-project] better Behavior>>methodDict

by Mariano Martinez Peck

On Wed, Feb 8, 2012 at 6:08 PM, Mariano Martinez Peck <marianopeck(a)gmail.com > wrote: > > > On Wed, Feb 8, 2012 at 4:04 PM, Nicolas Cellier < > nicolas.cellier.aka.nice(a)gmail.com> wrote: > >> I think that my first proposition was more a negative speculation than >> a really useful comment. >> It was more to emphasize the hackish nature of this change than to >> help future readers ;) >> >> > Even if the real motivation is hackish, I am not copletly sure that this > solution is negative. It somehow can be seen as the "null pattern" and > avoid checking for #isNil all the time. Apart from that, I think this > "pattern" is already present in Pharo, like: > > Class >> subclasses > "Answer a Set containing the receiver's subclasses." > > ^subclasses == nil > ifTrue: [#()] > ifFalse: [subclasses copy] > > > >> If you really want to include this change, I think you shall mention >> the true purpose of this hack, and I guess this would be something >> like: >> "In order to prevent the complaints of tools and IDE unaware of this >> feature, we try to fool them by providing an empty MethodDictionary." >> >> Eventually, you could mention your expected outcomes: >> "This will hopefully work in most cases, but the tools will loose the >> ability to modify the behaviour of such class." >> >> > True. But I guess if someone is using #cannotInterpert: then it is someone > who really understand the consequences. > Moreover, such developer can use #methodDict: later on if desired and hence the ability to modify the behavior comes back > But it is not bad to mention it anyway ;) > > >> Of course, I don't know the context into which you want to use >> cannotInterpret: so it is hard to tell if the system deserve such >> hack. >> > > Better proxy implementations. > > > >> I guess you might also add a message stating whether the class is >> subject to such cannotInterpret: hook or not, maybe something like >> >> Behavior>canInterpret >> "If methodDict instance variable is nil, this Behavior cannot >> interpret any message. >> In this case, every message sent to my instances will be >> redirected to a cannotInterpret: send, starting look-up at etc..." >> ^methodDict notNil >> >> Nicolas >> >> 2012/2/8 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: >> > mariano can you add a bug entry and we integrate it. >> > >> > Stef >> > >> > On Feb 7, 2012, at 1:00 AM, Nicolas Cellier wrote: >> > >> >> How many senders of #methodDict would miss-behave? >> >> No risk to throw away a freshly basicAddedSelector:withMethod: ? >> >> Or should the IDE be aware of the cannotInterpret: experiments ? >> >> >> >> Maybe the comment should be (seriously): >> >> >> >> "When methodDict instance variable of a class is nil, the VM will >> >> redirect any message send to an instance by sending the message >> >> cannotInterpret: to the receiver but starting the look up in the >> >> superclass. >> >> NDLR: Or is it to the next superclass having a non nil methodDict? >> >> Since most senders of #methodDict message are unaware of this feature, >> >> we try to fool them by providing a new empty MethodDictionary in this >> >> case, which shall hopefully make them apparently work. Whether >> >> undesirable side effect might occur or not, silently or not, is >> >> unspecified. Cross your fingers..." >> >> >> >> Nicolas >> >> >> >> 2012/2/6 Mariano Martinez Peck <marianopeck(a)gmail.com>: >> >>> >> >>> >> >>> On Mon, Feb 6, 2012 at 10:17 PM, StÃ©phane Ducasse >> >>> <Stephane.Ducasse(a)inria.fr> wrote: >> >>>> >> >>>> Hi mariano >> >>>> >> >>>> I have the impression that methodDict should be redefined as you >> propose >> >>>> it because else it does not work well with the cannotInterpret hook. >> I >> >>>> suggest to redefine methodDict as follow. notice the cool comment!!! >> >>>> If this is ok -> open a bug entry. >> >>>> >> >>>> >> >>>> Behavior >> methodDict >> >>>> "The method dictionary of a class can be nil when we want to >> use >> >>>> the cannotInterpret: hook. Indeed when a class dictionary is nil, >> the VM >> >>>> sends the message cannotInterpret: to the receiver but starting the >> look up >> >>>> in the superclass. Now the system relies that when the message >> methodDict is >> >>>> sent to a class a method dictionary is returned. The implementation >> below >> >>>> makes sure that a method dictionary can be nilled but does not >> confuse the >> >>>> system." >> >>>> >> >>>> methodDict == nil ifTrue: [^ MethodDictionary new ]. >> >>>> ^ methodDict >> >>>> >> >>> >> >>> For me that's perfect and avoids an override in my code :) >> >>> >> >>> Maybe we can do: >> >>> >> >>> >> >>> Behavior >> methodDict >> >>> "The method dictionary of a class can be nil when we want to >> use the >> >>> cannotInterpret: hook. Indeed when a class dictionary is nil, the VM >> sends >> >>> the message cannotInterpret: to the receiver but starting the look up >> in the >> >>> superclass. Now the system relies that when the message methodDict is >> sent >> >>> to a class a method dictionary is returned. The implementation below >> makes >> >>> sure that a method dictionary can be nilled but does not confuse the >> >>> system." >> >>> >> >>> methodDict == nil ifTrue: [^ self manageMDFault ]. >> >>> ^ methodDict >> >>> >> >>> >> >>> Behavior >> manageMDFault >> >>> >> >>> ^ MethodDictionary new >> >>> >> >>> >> >>> That way subclasses can change it without needing an override. >> >>> >> >>> but both solutions are fine with me. Other opinions? >> >>> >> >>> >> >>> -- >> >>> Mariano >> >>> http://marianopeck.wordpress.com >> >>> >> >> >> > >> > >> >> > > > -- > Mariano > http://marianopeck.wordpress.com > > -- Mariano http://marianopeck.wordpress.com

Feb. 8, 2012

Re: [Pharo-project] better Behavior>>methodDict

by Mariano Martinez Peck

On Wed, Feb 8, 2012 at 4:04 PM, Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com> wrote: > I think that my first proposition was more a negative speculation than > a really useful comment. > It was more to emphasize the hackish nature of this change than to > help future readers ;) > > Even if the real motivation is hackish, I am not copletly sure that this solution is negative. It somehow can be seen as the "null pattern" and avoid checking for #isNil all the time. Apart from that, I think this "pattern" is already present in Pharo, like: Class >> subclasses "Answer a Set containing the receiver's subclasses." ^subclasses == nil ifTrue: [#()] ifFalse: [subclasses copy] > If you really want to include this change, I think you shall mention > the true purpose of this hack, and I guess this would be something > like: > "In order to prevent the complaints of tools and IDE unaware of this > feature, we try to fool them by providing an empty MethodDictionary." > > Eventually, you could mention your expected outcomes: > "This will hopefully work in most cases, but the tools will loose the > ability to modify the behaviour of such class." > > True. But I guess if someone is using #cannotInterpert: then it is someone who really understand the consequences. But it is not bad to mention it anyway ;) > Of course, I don't know the context into which you want to use > cannotInterpret: so it is hard to tell if the system deserve such > hack. > Better proxy implementations. > I guess you might also add a message stating whether the class is > subject to such cannotInterpret: hook or not, maybe something like > > Behavior>canInterpret > "If methodDict instance variable is nil, this Behavior cannot > interpret any message. > In this case, every message sent to my instances will be > redirected to a cannotInterpret: send, starting look-up at etc..." > ^methodDict notNil > > Nicolas > > 2012/2/8 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > > mariano can you add a bug entry and we integrate it. > > > > Stef > > > > On Feb 7, 2012, at 1:00 AM, Nicolas Cellier wrote: > > > >> How many senders of #methodDict would miss-behave? > >> No risk to throw away a freshly basicAddedSelector:withMethod: ? > >> Or should the IDE be aware of the cannotInterpret: experiments ? > >> > >> Maybe the comment should be (seriously): > >> > >> "When methodDict instance variable of a class is nil, the VM will > >> redirect any message send to an instance by sending the message > >> cannotInterpret: to the receiver but starting the look up in the > >> superclass. > >> NDLR: Or is it to the next superclass having a non nil methodDict? > >> Since most senders of #methodDict message are unaware of this feature, > >> we try to fool them by providing a new empty MethodDictionary in this > >> case, which shall hopefully make them apparently work. Whether > >> undesirable side effect might occur or not, silently or not, is > >> unspecified. Cross your fingers..." > >> > >> Nicolas > >> > >> 2012/2/6 Mariano Martinez Peck <marianopeck(a)gmail.com>: > >>> > >>> > >>> On Mon, Feb 6, 2012 at 10:17 PM, StÃ©phane Ducasse > >>> <Stephane.Ducasse(a)inria.fr> wrote: > >>>> > >>>> Hi mariano > >>>> > >>>> I have the impression that methodDict should be redefined as you > propose > >>>> it because else it does not work well with the cannotInterpret hook. I > >>>> suggest to redefine methodDict as follow. notice the cool comment!!! > >>>> If this is ok -> open a bug entry. > >>>> > >>>> > >>>> Behavior >> methodDict > >>>> "The method dictionary of a class can be nil when we want to > use > >>>> the cannotInterpret: hook. Indeed when a class dictionary is nil, the > VM > >>>> sends the message cannotInterpret: to the receiver but starting the > look up > >>>> in the superclass. Now the system relies that when the message > methodDict is > >>>> sent to a class a method dictionary is returned. The implementation > below > >>>> makes sure that a method dictionary can be nilled but does not > confuse the > >>>> system." > >>>> > >>>> methodDict == nil ifTrue: [^ MethodDictionary new ]. > >>>> ^ methodDict > >>>> > >>> > >>> For me that's perfect and avoids an override in my code :) > >>> > >>> Maybe we can do: > >>> > >>> > >>> Behavior >> methodDict > >>> "The method dictionary of a class can be nil when we want to > use the > >>> cannotInterpret: hook. Indeed when a class dictionary is nil, the VM > sends > >>> the message cannotInterpret: to the receiver but starting the look up > in the > >>> superclass. Now the system relies that when the message methodDict is > sent > >>> to a class a method dictionary is returned. The implementation below > makes > >>> sure that a method dictionary can be nilled but does not confuse the > >>> system." > >>> > >>> methodDict == nil ifTrue: [^ self manageMDFault ]. > >>> ^ methodDict > >>> > >>> > >>> Behavior >> manageMDFault > >>> > >>> ^ MethodDictionary new > >>> > >>> > >>> That way subclasses can change it without needing an override. > >>> > >>> but both solutions are fine with me. Other opinions? > >>> > >>> > >>> -- > >>> Mariano > >>> http://marianopeck.wordpress.com > >>> > >> > > > > > > -- Mariano http://marianopeck.wordpress.com

Feb. 8, 2012

[Pharo-project] [update 1.4] #14322

by Marcus Denker

14322 ----- Issue 5170: DNU Inspector>>arrowKey:from: http://code.google.com/p/pharo/issues/detail?id=5170 Issue 5252: Cannot right click http://code.google.com/p/pharo/issues/detail?id=5252 Issue 4650: Strange $ evaluates to Character arrowUp http://code.google.com/p/pharo/issues/detail?id=4650 -- Marcus Denker -- http://marcusdenker.de

Feb. 8, 2012