This document discusses issues with thisContext in the Pharo debugger not correctly representing the execution context and being the DoIt context instead. This was fixed in Pharo12 by making thisContext a variable object that is wrapped in a DoItVariable, so the debugger context is used. When inspecting or printing in the debugger, it pushes the DoItVariable and sends the read message to correctly display the thisContext.

1. thisContext
in the Debugger
Marcus Denker
Inria Evref

2. Problem

3. Problem
• When reading thisContext in the Debugger via inspect-it
(or during doIt execution) is not correct
• It is the context of the DoIt (!)

4. Fixed in Pharo12

5. Fixed in Pharo12
• thisContext in the Debugger is the context that the
debugger is in
• For inspect / print / DoIt

6. How?
• In Pharo Variables are Objects
• There is ThisContextVariable
• Wrapped in a DoItVariable which adds the Context
• Compiler emits code:
• push the doIt Variable
• send #read

7. All Details
https://blog.marcusdenker.de/improving-thiscontext-in-the-debugger-using-
fi
rst-class-variables