Make nested IsInstantiables with Data in them work (#2761) (#2766)

* Add unit test for Issue 2760

* checkpoint: Fix for nested instance

* remove comments about stuff not working

* make the test check the output a little more

* relax the requirement on returning empty ioMap

* Update core/src/main/scala/chisel3/experimental/hierarchy/core/Lookupable.scala

* Update core/src/main/scala/chisel3/Data.scala

* Update core/src/main/scala/chisel3/experimental/hierarchy/core/Lookupable.scala

Co-authored-by: Jack Koenig <koenig@sifive.com>

* Update src/test/scala/chiselTests/experimental/hierarchy/InstanceSpec.scala

Co-authored-by: Jack Koenig <koenig@sifive.com>

* Update core/src/main/scala/chisel3/experimental/hierarchy/core/Lookupable.scala

* Add another unit test which unfortunately still passes

* Update core/src/main/scala/chisel3/Data.scala

* Update src/test/scala/chiselTests/experimental/hierarchy/InstanceSpec.scala

Co-authored-by: Jack Koenig <koenig@sifive.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
(cherry picked from commit 1f9f26dc2bffcb4cc4daf2dc16c5cb455c6769ef)

Co-authored-by: Megan Wachs <megan@sifive.com>

1 files changed, 13 insertions, 4 deletions

diff --git a/core/src/main/scala/chisel3/experimental/hierarchy/Lookupable.scala b/core/src/main/scala/chisel3/experimental/hierarchy/Lookupable.scala
index c83479b0..aa35455d 100644
--- a/core/src/main/scala/chisel3/experimental/hierarchy/Lookupable.scala
+++ b/core/src/main/scala/chisel3/experimental/hierarchy/Lookupable.scala
@@ -335,11 +335,20 @@ object Lookupable {
       }
       def instanceLookup[A](that: A => B, instance: Instance[A]): C = {
         val ret = that(instance.proto)
-        val ioMap: Option[Map[Data, Data]] = instance.underlying match {
-          case Clone(x: ModuleClone[_]) => Some(x.ioMap)
-          case Proto(x: BaseModule) => Some(x.getChiselPorts.map { case (_, data) => data -> data }.toMap)
-          case _ => None
+
+        def getIoMap(hierarchy: Hierarchy[_]): Option[Map[Data, Data]] = {
+          hierarchy.underlying match {
+            case Clone(x: ModuleClone[_]) => Some(x.ioMap)
+            case Proto(x: BaseModule) => Some(x.getChiselPorts.map { case (_, data) => data -> data }.toMap)
+            case Clone(x: InstantiableClone[_]) => getIoMap(x._innerContext)
+            case Clone(x: InstanceClone[_]) => None
+            case other => {
+              Builder.exception(s"Internal Error! Unexpected case where we can't get IO Map: $other")
+            }
+          }
         }
+        val ioMap = getIoMap(instance)
+
         if (isView(ret)) {
           cloneViewToContext(ret, instance.cache, ioMap, instance.getInnerDataContext)
         } else {