[Vm-dev] Bug in #instVarAt:put: for read-only objects

[Clément Bera]

On Fri, Jan 5, 2018 at 2:34 PM, Eliot Miranda <eliot.miranda at gmail.com>
wrote:

>
> Hi Clément,
>
>     is it too late to take a look at the VisualWorks code and use the same
> class names and selectors they use?  IIRC it is NoMidificationError.  It
> may make e.g. Gemstone's job easier if there is some consistency.
>
>
That was discussed on the Pharo mailing list.

I used the same name and it was changed by other contributors.



> _,,,^..^,,,_ (phone)
>
> On Jan 5, 2018, at 5:22 AM, Clément Bera <bera.clement at gmail.com> wrote:
>
> Hi,
>
> No this is not a bug.
>
> This needs to be handled in the primitive failure code in the image, the
> method should be something like that :
>
> Object>>instVarAt: index put: anObject
> <primitive: 174 error: ec>
>         self isReadOnlyObject ifTrue: [(ModificationForbidden for: self
> atInstVar: index with: anObject) signal]
> self primitiveFailed
>
> All primitive fall-back code triggering object mutation should be
> rewritten this way, especially primitives such as #at:put:,
> #instVarAt:put:, etc.
>
> Cheers
>
> On Fri, Jan 5, 2018 at 1:42 PM, Norbert Hartl <norbert at hartl.name> wrote:
>
>>
>> If I do
>>
>> (#foo -> #bar)
>> beReadOnlyObject;
>> value: #baz
>>
>> it throws
>>
>> *ModificationForbidden:  #foo->#bar is read-only, hence its field 2
>> cannot be modified with #baz*
>>
>>  which is as expected. But if I do
>>
>> (#foo -> #bar)
>> beReadOnlyObject;
>> instVarNamed: #value put: #baz
>>
>> I get
>>
>> *PrimitiveFailed: primitive #instVarAt:put: in Association failed*
>>
>> I think this a bug, no?
>>
>> Norbert
>>
>>
>
>
> --
> Clément Béra
> Pharo consortium engineer
> https://clementbera.wordpress.com/
> Bâtiment B 40, avenue Halley 59650 Villeneuve d'Ascq
>
>
>


-- 
Clément Béra
Pharo consortium engineer
https://clementbera.wordpress.com/
Bâtiment B 40, avenue Halley 59650 Villeneuve d'Ascq
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