Add InlineInstance API

This adds a new trait, InlineInstance, to chisel3.util.experimental. This
trait, when mixed into a specific module or instance, will "inline" that
module, i.e., "collapse a module while preserving it's submodules."

This includes testing (InlineSpec) and ScalaDoc documentation.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/src/main/scala/chisel3/util/experimental/Inline.scala b/src/main/scala/chisel3/util/experimental/Inline.scala
new file mode 100644
index 00000000..4039f3ed
--- /dev/null
+++ b/src/main/scala/chisel3/util/experimental/Inline.scala
@@ -0,0 +1,50 @@
+// See LICENSE for license details.
+
+package chisel3.util.experimental
+
+import chisel3._
+import chisel3.internal.InstanceId
+import chisel3.experimental.{BaseModule, ChiselAnnotation, RunFirrtlTransform}
+import firrtl.Transform
+import firrtl.passes.{InlineAnnotation, InlineInstances}
+import firrtl.transforms.{NoDedupAnnotation, FlattenAnnotation, Flatten}
+import firrtl.annotations.{CircuitName, ModuleName, ComponentName, Annotation}
+
+/** Inlines an instance of a module
+  *
+  * @example {{{
+  * trait Internals { this: Module =>
+  *   val io = IO(new Bundle{ val a = Input(Bool()) })
+  * }
+  * class Sub extends Module with Internals
+  * trait HasSub { this: Module with Internals =>
+  *   val sub = Module(new Sub)
+  *   sub.io.a := io.a
+  * }
+  * /* InlineInstance is mixed directly into Foo's definition. Every instance
+  *  * of this will be inlined. */
+  * class Foo extends Module with Internals with InlineInstance with HasSub
+  * /* Bar will, by default, not be inlined */
+  * class Bar extends Module with Internals with HasSub
+  * /* The resulting instances will be:
+  *  - Top
+  *  - Top.x$sub
+  *  - Top.y$sub
+  *  - Top.z
+  *  - Top.z.sub */
+  * class Top extends Module with Internals {
+  *   val x = Module(new Foo)                     // x will be inlined
+  *   val y = Module(new Bar with InlineInstance) // y will also be inlined
+  *   val z = Module(new Bar)                     // z will not be inlined
+  *   Seq(x, y, z).map(_.io.a := io.a)
+  * }
+  * }}}
+  */
+trait InlineInstance { self: BaseModule =>
+  Seq(new ChiselAnnotation with RunFirrtlTransform {
+        def toFirrtl: Annotation = InlineAnnotation(self.toNamed)
+        def transformClass: Class[_ <: Transform] = classOf[InlineInstances] },
+      new ChiselAnnotation {
+        def toFirrtl: Annotation = NoDedupAnnotation(self.toNamed) })
+    .map(chisel3.experimental.annotate(_))
+}