the cloneType and chiselCloneType hot mess 🔥 (#653)

Addresses #419

cloneType is now marked (through comments only) as an internal API.
chiselCloneType deprecated (and changed to cloneTypeFull internally, analogous to cloneTypeWidth).
chiselTypeOf(data) introduced as the external API to get a chisel type from a hardware object
Intended usage: cloning is an implementation detail, and chisel types and hardware objects both should act as immutable types, with operations like Input(...), Reg(...), etc returning a copy and leaving the original unchanged. Hence, the clone operations are all deprecated.
Deletes what appears to be an unused Bundle companion object.
Input(...), Output(...), Flipped(...) require the object to be unbound

6 files changed, 18 insertions, 5 deletions

diff --git a/src/main/scala/chisel3/compatibility.scala b/src/main/scala/chisel3/compatibility.scala
index f181caba..d65196d9 100644
--- a/src/main/scala/chisel3/compatibility.scala
+++ b/src/main/scala/chisel3/compatibility.scala
@@ -42,6 +42,12 @@ package object Chisel {     // scalastyle:ignore package.object.name
       }
     }
   }
+  implicit class cloneTypeable[T <: Data](val target: T) extends AnyVal {
+    import chisel3.core.DataMirror
+    def chiselCloneType: T = {
+      DataMirror.internal.chiselTypeClone(target).asInstanceOf[T]
+    }
+  }
 
   type ChiselException = chisel3.internal.ChiselException
 
diff --git a/src/main/scala/chisel3/package.scala b/src/main/scala/chisel3/package.scala
index ee77ba23..d335f1f1 100644
--- a/src/main/scala/chisel3/package.scala
+++ b/src/main/scala/chisel3/package.scala
@@ -19,6 +19,7 @@ package object chisel3 {    // scalastyle:ignore package.object.name
   val Input   = chisel3.core.Input
   val Output  = chisel3.core.Output
   val Flipped = chisel3.core.Flipped
+  val chiselTypeOf = chisel3.core.chiselTypeOf
 
   type Data = chisel3.core.Data
   object Wire extends chisel3.core.WireFactory {
@@ -56,6 +57,13 @@ package object chisel3 {    // scalastyle:ignore package.object.name
     }
   }
 
+  implicit class cloneTypeable[T <: Data](val target: T) extends AnyVal {
+    @deprecated("chiselCloneType is deprecated, use chiselTypeOf(...) to get the Chisel Type of a hardware object", "chisel3")
+    def chiselCloneType: T = {
+      target.cloneTypeFull.asInstanceOf[T]
+    }
+  }
+
   type Aggregate = chisel3.core.Aggregate
   object Vec extends chisel3.core.VecFactory {
     import scala.language.experimental.macros
diff --git a/src/main/scala/chisel3/util/Decoupled.scala b/src/main/scala/chisel3/util/Decoupled.scala
index ef09c07d..451fd039 100644
--- a/src/main/scala/chisel3/util/Decoupled.scala
+++ b/src/main/scala/chisel3/util/Decoupled.scala
@@ -281,7 +281,7 @@ object Queue
       entries: Int = 2,
       pipe: Boolean = false,
       flow: Boolean = false): DecoupledIO[T] = {
-    val q = Module(new Queue(enq.bits.cloneType, entries, pipe, flow))
+    val q = Module(new Queue(chiselTypeOf(enq.bits), entries, pipe, flow))
     q.io.enq.valid := enq.valid // not using <> so that override is allowed
     q.io.enq.bits := enq.bits
     enq.ready := q.io.enq.ready
diff --git a/src/main/scala/chisel3/util/Reg.scala b/src/main/scala/chisel3/util/Reg.scala
index 34c4d6d8..34d22a07 100644
--- a/src/main/scala/chisel3/util/Reg.scala
+++ b/src/main/scala/chisel3/util/Reg.scala
@@ -8,8 +8,7 @@ object RegEnable {
   /** Returns a register with the specified next, update enable gate, and no reset initialization.
     */
   def apply[T <: Data](next: T, enable: Bool): T = {
-    val clonedNext = next.chiselCloneType
-    val r = Reg(clonedNext)
+    val r = Reg(chiselTypeOf(next))
     when (enable) { r := next }
     r
   }
diff --git a/src/test/scala/chiselTests/Module.scala b/src/test/scala/chiselTests/Module.scala
index 432cd278..e84e6a02 100644
--- a/src/test/scala/chiselTests/Module.scala
+++ b/src/test/scala/chiselTests/Module.scala
@@ -41,7 +41,7 @@ class ModuleVecTester(c: ModuleVec) extends Tester(c) {
 
 class ModuleWire extends Module {
   val io = IO(new SimpleIO)
-  val inc = Wire(Module(new PlusOne).io.chiselCloneType)
+  val inc = Wire(chiselTypeOf(Module(new PlusOne).io))
   inc.in := io.in
   io.out := inc.out
 }
diff --git a/src/test/scala/chiselTests/Vec.scala b/src/test/scala/chiselTests/Vec.scala
index 9b8855c4..6c62ab26 100644
--- a/src/test/scala/chiselTests/Vec.scala
+++ b/src/test/scala/chiselTests/Vec.scala
@@ -145,7 +145,7 @@ class ZeroEntryVecTester extends BasicTester {
   require(bundleWithZeroEntryVec.asUInt.getWidth == 1)
 
   val m = Module(new Module {
-    val io = IO(Output(bundleWithZeroEntryVec.cloneType))
+    val io = IO(Output(bundleWithZeroEntryVec))
   })
   WireInit(m.io.bar)