RawModule with no reset should be able to use withClock method. (#1065)

* RawModule with no reset should be able to use withClock method.
- refactor ClockAndReset
  - now has `clockOpt: Option[Clock]` and `resetOpt: Option[Reset]` constructor params
  - convenience methods clock and reset tries to deref the option
  - ClockAndReset.empty is factory method for (None, None)
- In Builder
  - forcedClock does not check resetOpt now
  - forcedReset does not check clockOpt now
- withClock no longer looks at resetOpt
- withReset no longer looks at clockOpt
- Module starts with empty ClockAndReset

* RawModule with no reset should be able to use withClock method.
Refactor again based on @ducky64 comments
- refactor away ClockAndReset, now builder just has a
  - currentClock
  - currentReset
- withClock, withRest, withClockAndReset just use these fields directly

* RawModule with no reset should be able to use withClock method.
- Fixed typo in withReset handler, now picks up new reset

1 files changed, 6 insertions, 4 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/Module.scala b/chiselFrontend/src/main/scala/chisel3/core/Module.scala
index f97d51ac..5cd48a6a 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Module.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Module.scala
@@ -41,8 +41,9 @@ object Module extends SourceInfoDoc {
     val whenDepth: Int = Builder.whenDepth
 
     // Save then clear clock and reset to prevent leaking scope, must be set again in the Module
-    val clockAndReset: Option[ClockAndReset] = Builder.currentClockAndReset
-    Builder.currentClockAndReset = None
+    val (saveClock, saveReset)  = (Builder.currentClock, Builder.currentReset)
+    Builder.currentClock = None
+    Builder.currentReset = None
 
     // Execute the module, this has the following side effects:
     //   - set currentModule
@@ -59,9 +60,10 @@ object Module extends SourceInfoDoc {
                      "This is probably due to rewrapping a Module instance with Module()." +
                      sourceInfo.makeMessage(" See " + _))
     }
-    Builder.currentModule = parent // Back to parent!
+    Builder.currentModule = parent     // Back to parent!
     Builder.whenDepth = whenDepth
-    Builder.currentClockAndReset = clockAndReset // Back to clock and reset scope
+    Builder.currentClock = saveClock   // Back to clock and reset scope
+    Builder.currentReset = saveReset
 
     val component = module.generateComponent()
     Builder.components += component