1 files changed, 41 insertions, 0 deletions
diff --git a/core/src/main/scala/chisel3/IO.scala b/core/src/main/scala/chisel3/IO.scala
new file mode 100644
index 00000000..1a28db1e
--- /dev/null
+++ b/core/src/main/scala/chisel3/IO.scala
@@ -0,0 +1,41 @@
+package chisel3
+
+import chisel3.internal.requireIsChiselType // Fix ambiguous import
+import chisel3.internal.Builder
+import chisel3.internal.sourceinfo.SourceInfo
+
+object IO {
+
+  /** Constructs a port for the current Module
+    *
+    * This must wrap the datatype used to set the io field of any Module.
+    * i.e. All concrete modules must have defined io in this form:
+    * [lazy] val io[: io type] = IO(...[: io type])
+    *
+    * Items in [] are optional.
+    *
+    * The granted iodef must be a chisel type and not be bound to hardware.
+    *
+    * Also registers a Data as a port, also performing bindings. Cannot be called once ports are
+    * requested (so that all calls to ports will return the same information).
+    * Internal API.
+    */
+  def apply[T <: Data](iodef: T): T = {
+    val module = Module.currentModule.get // Impossible to fail
+    require(!module.isClosed, "Can't add more ports after module close")
+    requireIsChiselType(iodef, "io type")
+
+    // Clone the IO so we preserve immutability of data types
+    val iodefClone =
+      try {
+        iodef.cloneTypeFull
+      } catch {
+        // For now this is going to be just a deprecation so we don't suddenly break everyone's code
+        case e: AutoClonetypeException =>
+          Builder.deprecated(e.getMessage, Some(s"${iodef.getClass}"))
+          iodef
+      }
+    module.bindIoInPlace(iodefClone)
+    iodefClone
+  }
+}