Hi. There is something I don't understand about #cannotInterpret and maybe you can help me. Since I am not sure if this is more image side or vm, I did a cross post, sorry for that.
Context: I am implementing proxies for classes. Since I want that a proxy loads back the original object when receiving the message #class, I have removed from the compiler the shortcut bytecode for class, with this:
(ParseNode classVarNamed:� 'StdSelectors') removeKey: #class ifAbsent: [].
Now, my testcase is something like this:
��� | inst proxy |
��� "This is the simplest test that does the less assert as possible."
��� inst := ClassWith1Var new.
��� self assert: inst foo = 'foo'.
��� proxy := ClassProxyInstVar new.
��� proxy become: ClassWith1Var.
��� "here I can send any message, it is just to load back the original class"
��� inst basicIdentityHash.
��� self assert: (inst class == ClassWith1Var).
��� self assert: inst foo = 'foo'.
ProtoObject subclass: #ClassProxyInstVar
��� instanceVariableNames: 'superclass methodDict format actualClass'
��� classVariableNames: ''
��� poolDictionaries: ''
��� category: 'Proxies'
ClassProxyInstVar >> initialize
��� super initialize.
��� superclass := ProxySuperclass.
��� methodDict := nil.
��� actualClass := self
So...with this i can use an instance of ClassProxyInstVar like a class. When an instance of the class receives a message, the methodDict will be in nil, and then the VM will send the #cannotInterpret. and there I want to put back the original class. Then I do:
ProxySuperclass >> cannotInterpret: aMessage
��� Transcript cr;
��� ��� show: 'cannotInterpret:';
��� ��� space;
��� ��� show: aMessage selector..
��� self class restore.
��� ^aMessage sendTo: self
Now, this is working, but there is something I DO NOT UNSERSTAND. When I try to do the "inst basicIdentityHash" the VM will send the #cannotInterpret to ProxySuperclass because the methodDict was nil in ClassProxyInstVar. Ok, perfect. What I don't understand is how the method #cannotInterptet can be run perfeclty in this case, since I am doing a "self class restore" there. Remember I removed the shortcut bytecode, so #class is sent like any normal message. So, my question is, when sending "self class", why the VM doesn't call #cannotInterpter again like it did it when I did "�� inst basicIdentityHash."� ?� in other words...why the VM isn't entering in a loop ? � There is something I am not seeing.
Thanks for any help in advance,
Mariano