[armedbear-devel] Questions about r14452 (Fix cl-cont)

[Erik Huelsmann]

Forgot to mention: Pre 14452 it was enough to just quickload cl-cont to
trigger the bug.

Bye, Erik

sent from my phone
On Apr 2, 2013 7:52 PM, "Erik Huelsmann" <ehuels at gmail.com> wrote:

> Hi Rudi,
>
> Basically the expectation we violated was the fact that %set-lambda-name
> didn't want to take a funcallable instance as its function argument. The
> commit changed that and used the first slot  of the funcallable  instance
> class layout (called NAME) to store the name. I guess we forget to finalize
> the class somewhere, so the spots don't appear?
>
> Bye,
>
> Erik.
>
> sent from my phone
> On Apr 2, 2013 7:32 PM, "Rudolf Schlatte" <rudi at constantly.at> wrote:
>
>> Hi,
>>
>> I suspect that the changes in commit r14452 only work by accident.
>>
>> The definions of SLOT_INDEX_NAME in FuncallableStandardClass vs
>> FuncallableStandardObject are no problem, since the latter simply isn't
>> used anywhere.  But the new methods getName() and setName() assume that a)
>> the FuncallableStandardObject instance has at least one slot, and b) that
>> slot holds a name.  Since
>>     (class-slots (find-class 'funcallable-standard-object))
>> returns NIL, these assumptions hold only when the objects are in fact
>> generic functions.
>>
>> Amusingly,
>>     (function-lambda-expression (make-instance
>> 'funcallable-standard-object))
>> runs into the type error on line 2666 of Primitives.lisp ("The value
>> #<FUNCALLABLE-STANDARD-OBJECT {665C5A83}> is not of type FUNCTION.") even
>> though
>>     (typep (make-instance 'funcallable-standard-object) 'function) => T
>> so I can't trigger the array-out-of-bounds error right now.
>>
>> Could I have a recipe for triggering the bug?  I'd like to see how
>> cl-cont uses funcallable-standard-objects, and what expectations we
>> violate.  I believe I can fix this properly.
>>
>> Cheers,
>>
>> Rudi
>>
>>
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