[Vm-dev] [VM CRASH, 201710061559, Cog/Spur, Win32] Cannot step-over using object-as-method

Eliot Miranda eliot.miranda at gmail.com
Tue Oct 10 19:40:36 UTC 2017


Hi Marcel,


> On Oct 10, 2017, at 6:54 AM, Marcel Taeumel <marcel.taeumel at hpi.de> wrote:
> 
> Hi, there.
> 
> There seems to be a bug in the VM that occurs when stepping over a call that is actually a regular object in a method dictionary.
> 
> The VM crashes in the primitive 76.
> 
> To reproduce the bug load the attached change set and run the following code to install the "fake" method:
> 
> Blubb methodDict at: #fake put: (BlubbMethod new original: (Blubb >> #original)).
> 
> Now do this in the workspace:
> 
> self halt.
> Blubb new fake.
> 
> Then "step over" a few times. The VM crashes. This is not a new bug. The VM crashes also in:
> 
> Squeak 4.6, VM 3397 (Cog V3)
> Squeak 4.5, VM 2776 (Cog V3)
> Squeak 4.3, VM Squeak 4.1.1 (no Cog, Stack VM)
> 
> In Squeak 4.4 (VM 2776, Cog V3), I get a "SmallInteger DNU 137504030". No VM crash. :)
> In Squeak 3.8 (InterpreterVM?), I get a "Where is the jump??" error raised in MethodContext(InstructionStream) >> #skipBackBeforeJump. No VM crash. :)

I will try and take a look at this early next week.  

> 
> Best,
> Marcel
> <object-as-method-bug.1.cs>
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