Views of Probes of Aggregates cause Stack Overflow errors

[jackkoenig]

Type of issue: Bug Report

Please provide the steps to reproduce the problem:

Consider the following Chisel:

//> using scala "2.13.12"
//> using dep "org.chipsalliance::chisel:6.4.0"
//> using plugin "org.chipsalliance:::chisel-plugin:6.4.0"
//> using options "-unchecked", "-deprecation", "-language:reflectiveCalls", "-feature", "-Xcheckinit", "-Xfatal-warnings", "-Ywarn-dead-code", "-Ywarn-unused", "-Ymacro-annotations"

import chisel3._
import chisel3.probe._
import chisel3.experimental.dataview._
// _root_ disambiguates from package chisel3.util.circt if user imports chisel3.util._
import _root_.circt.stage.ChiselStage

class MyBundle extends Bundle {
  val a = UInt(8.W)
  val b = UInt(8.W)
}

class Foo extends RawModule {
  val out = IO(Output(Probe(new MyBundle)))
}

class Top extends RawModule {
  val f = Module(new Foo)

  f.out.viewAs.isLit
}

object Main extends App {
  println(
    ChiselStage.emitCHIRRTL(
      gen = new Top
    )
  )
}

What is the current behavior?

The f.out.viewAs.isLit will cause a stack overflow.

What is the expected behavior?

Views of Probes of Aggregates should work!

Please tell us about your environment:

Other Information

What is the use case for changing the behavior?