Make it possible to GC Data instances

No longer create a pointer from parent to every HasId, only do it by
default for BaseModules and MemBases. Add pointer from parent to Data
upon binding the Data.

* Add MemTypeBinding for port types of Mems

This binding is similar to the SampleElementBinding for Vecs in that
these Data are not truly hardware, but are represented in the FIRRTL IR
and thus need some representation.

* Call _onModuleClose on unbound Records

This maintains some corner-case behavior that is nevertheless relied
upon. It ensures that refs are set for the elements of Records, even if
they are not bound to any real hardware.

2 files changed, 4 insertions, 1 deletions

diff --git a/core/src/main/scala/chisel3/internal/Binding.scala b/core/src/main/scala/chisel3/internal/Binding.scala
index 4442c62e..9e17aded 100644
--- a/core/src/main/scala/chisel3/internal/Binding.scala
+++ b/core/src/main/scala/chisel3/internal/Binding.scala
@@ -110,6 +110,10 @@ case class ChildBinding(parent: Data) extends Binding {
 case class SampleElementBinding[T <: Data](parent: Vec[T]) extends Binding {
   def location = parent.topBinding.location
 }
+/** Special binding for Mem types */
+case class MemTypeBinding[T <: Data](parent: MemBase[T]) extends Binding {
+  def location: Option[BaseModule] = parent._parent
+}
 // A DontCare element has a specific Binding, somewhat like a literal.
 // It is a source (RHS). It may only be connected/applied to sinks.
 case class DontCareBinding() extends UnconstrainedBinding
diff --git a/core/src/main/scala/chisel3/internal/Builder.scala b/core/src/main/scala/chisel3/internal/Builder.scala
index b7772aea..31d4666c 100644
--- a/core/src/main/scala/chisel3/internal/Builder.scala
+++ b/core/src/main/scala/chisel3/internal/Builder.scala
@@ -84,7 +84,6 @@ trait InstanceId {
 private[chisel3] trait HasId extends InstanceId {
   private[chisel3] def _onModuleClose: Unit = {}
   private[chisel3] val _parent: Option[BaseModule] = Builder.currentModule
-  _parent.foreach(_.addId(this))
 
   private[chisel3] val _id: Long = Builder.idGen.next