Hi, this method of Interpreter is used for debugging, and should print the name of the class passed in console:<div><br></div><div><div>printNameOfClass: classOop count: cnt</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>"Details: The count argument is used to avoid a possible infinite recursion if classOop is a corrupted object."</div>
<div><br></div><div><span class="Apple-tab-span" style="white-space:pre"> </span>cnt <= 0 ifTrue: [ ^ self print: 'bad class' ].</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>(self sizeBitsOf: classOop) = (7 * self bytesPerWord)<span class="Apple-tab-span" style="white-space:pre"> </span>"(Metaclass instSize+1 * 4)"</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span>ifTrue: [self printNameOfClass: (self fetchPointer: 5 "thisClass" ofObject: classOop) </div><div><span class="Apple-tab-span" style="white-space:pre"> </span>count: cnt - 1.</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span>self print: ' class']</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>ifFalse: [self printStringOf: (self fetchPointer: 6 "name" ofObject: classOop)]</div>
<div><br></div><div>it's logic is this: if the classOop is of a normal Class instance, it should use the instance var number six, which corresponds to the class' name. If not, then the classOop represents a Metaclass instance, and then it will fetch inst var number 5, which is the corresponding class, print its name, and then print 'class' to let you distinguish it that it is a metaclass.</div>
<div><br></div><div>The problem of the method is that it determines if it's a class instance or a metaclass instance by looking at the size of the oop, which seems to have changed, at least in pharo (Metaclass instSize+1 * 4 = 36 = 9*bytesPerWord). </div>
<div><br></div><div>The method could be fixed by changing 7 to 9 then. But it will break if Metaclass changes again. So I have this idea: make it check if the classOop is a metaclass instance. Metaclass class is not a special object, but can be obtained by accessing any special one, like with </div>
<div><br></div><div>Integer class class</div><div><br></div><div>or directly with</div><div><br></div><div>nil class class class (!!)</div><div><br></div><div>then the proposed code is:</div><div><br></div><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><span class="Apple-style-span" style="white-space: pre;">printNameOfClass: classOop count: cnt
"Details: The count argument is used to avoid a possible infinite recursion if classOop is a corrupted object."
| metaclassClass |
cnt <= 0 ifTrue: [ ^ self print: 'bad class' ].
metaclassClass := self fetchClassOf: (self fetchClassOf: (self fetchPointer: ClassInteger ofObject: specialObjectsOop)).
metaclassClass = (self fetchClassOf: classOop) "Is it a metaclass?"
ifTrue: [self printNameOfClass: (self fetchPointer: 5 "thisClass" ofObject: classOop)
count: cnt - 1.
self print: ' class']
ifFalse: [self printStringOf: (self fetchPointer: 6 "name" ofObject: classOop)]</span></div><div><br></div><div><br></div><div>I'd also like to have this included too:</div><div><br></div><div><div>printClassOf: oop</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span>"Print the class of the oop in console"</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>self printNameOfClass: (self fetchClassOf: oop) count: 5. </div>
</div><div><br></div><div>which is simple but pretty much useful.</div><div><br></div><div>What do you think?</div><div><br></div><div>Regards,</div><div> Javier.</div><br>-- <br>Javier Pimás<br>Ciudad de Buenos Aires<br>
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