[squeak-dev] Bug: Debugger storm when trying to stepping into #withArgs:executeMethod:

Christoph Thiede christoph.thiede at outlook.de
Sun Jul 21 14:03:03 UTC 2019

Hi all,

steps to reproduce the issue:

1. Save your image (it will probably crash)
2. Type the following line into any CodeHolder:
nil withArgs: #() executeMethod: Object >> #class
3. DebugIt and step into #withArgs:executeMethod:

On my image (fairly up-to-date Trunk), the Debugger hangs and, recursively,
new debugger windows with an "Error: subscript is out of bounds: 0" will
open. I rarely manage to interrupt this error chain by pressing <cmd>dot ...

Is this a known bug?

I'm an absolute newbie in the matter of Debugger implementation &
primitives, but I was curious and tried my best to localize the defect (my
approach was debugging the debugger ...) and I found out the following: In
the given example, in Context>>#doPrimitive:method:receiver:args: the
primitive 188 is executed (why does the method comment speak of
"simulation"?). Now, `arguments` is `{#(), Object >> #class}`. There is made
an attempt to access `arguments at: n - 2` to determine `thisReceiver`, but
as `n = 2`, this gives an error.

As I said, I do not yet understand the whole intention of this code. But why
isn't `thisReceiver` simply set to `receiver`? I exchanged this line locally
to resolve the bug and could not find any error. But I did not found any
automated tests for the Context class either ...

I would greatly welcome your help and explanations!


Sent from: http://forum.world.st/Squeak-Dev-f45488.html

More information about the Squeak-dev mailing list