Fix stack overflow when using Probe with FlatIO

[Emin017]

The issue occurred when stringAccessor called reifySingleTarget, whichtriggered toString on mapped Data elements, creating an infinite loop: stringAccessor → reifySingleTarget → mapping(l) → toString → stringAccessor

Added a ThreadLocal guard in Data.stringAccessor to prevent recursivecalls to reifySingleTarget. When recursion is detected, the guard returnsthe current Data object without attempting view reification.

Fix #4687.

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• API modification
• Bugfix

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[jackkoenig]

Thank you for circling back on this @Emin017, we need to fix it. I don't think this is quite the right way to do it though--I have an alternative solution in https://github.com/chipsalliance/chisel/tree/jackkoenig/fix-dataview-overflow that I also don't think is quite right, but I will try to get a proper solution soon.

[Emin017]

Thank you for circling back on this @Emin017, we need to fix it. I don't think this is quite the right way to do it though--I have an alternative solution in https://github.com/chipsalliance/chisel/tree/jackkoenig/fix-dataview-overflow that I also don't think is quite right, but I will try to get a proper solution soon.

Thanks! I also tried fixing this bug from the DataView side, but didn’t succeed. Looking forward to your solution!