Aspect-Oriented Programming for Chisel (#1077)

Added Aspects to Chisel, enabling a mechanism for dependency injection to hardware modules.

1 files changed, 40 insertions, 0 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/aop/Aspect.scala b/chiselFrontend/src/main/scala/chisel3/aop/Aspect.scala
new file mode 100644
index 00000000..86f5b347
--- /dev/null
+++ b/chiselFrontend/src/main/scala/chisel3/aop/Aspect.scala
@@ -0,0 +1,40 @@
+// See LICENSE for license details.
+
+package chisel3.aop
+
+import chisel3.experimental.RawModule
+import firrtl.annotations.{Annotation, NoTargetAnnotation}
+import firrtl.options.Unserializable
+import firrtl.AnnotationSeq
+
+/** Represents an aspect of a Chisel module, by specifying
+  * what behavior should be done to instance, via the FIRRTL Annotation Mechanism
+  * @tparam T Type of top-level module
+  */
+abstract class Aspect[T <: RawModule] extends Annotation with Unserializable with NoTargetAnnotation {
+  /** Convert this Aspect to a seq of FIRRTL annotation
+    * @param top
+    * @return
+    */
+  def toAnnotation(top: T): AnnotationSeq
+
+  /** Called by [[chisel3.stage.phases.AspectPhase]] to resolve this Aspect into annotations
+    * @param top
+    * @return
+    */
+  private[chisel3] def resolveAspect(top: RawModule): AnnotationSeq = {
+    toAnnotation(top.asInstanceOf[T])
+  }
+}
+
+/** Holds utility functions for Aspect stuff */
+object Aspect {
+
+  /** Converts elaborated Chisel components to FIRRTL modules
+    * @param chiselIR
+    * @return
+    */
+  def getFirrtl(chiselIR: chisel3.internal.firrtl.Circuit): firrtl.ir.Circuit = {
+    chisel3.internal.firrtl.Converter.convert(chiselIR)
+  }
+}