Add checks for misuse or omission of Module()

Implemented by adding a Boolean to check for alternating invocations of object
Module.apply and the constructor of abstract class Module.
Fixes #192

1 files changed, 34 insertions, 0 deletions

diff --git a/src/test/scala/chiselTests/Module.scala b/src/test/scala/chiselTests/Module.scala
index 7a4050db..c902d073 100644
--- a/src/test/scala/chiselTests/Module.scala
+++ b/src/test/scala/chiselTests/Module.scala
@@ -69,6 +69,22 @@ class ModuleWhen extends Module {
   } otherwise { io.s.out := io.s.in }
 }
 
+class ModuleForgetWrapper extends Module {
+  val io = IO(new SimpleIO)
+  val inst = new PlusOne
+}
+
+class ModuleDoubleWrap extends Module {
+  val io = IO(new SimpleIO)
+  val inst = Module(Module(new PlusOne))
+}
+
+class ModuleRewrap extends Module {
+  val io = IO(new SimpleIO)
+  val inst = Module(new PlusOne)
+  val inst2 = Module(inst)
+}
+
 class ModuleSpec extends ChiselPropSpec {
 
   property("ModuleVec should elaborate") {
@@ -88,4 +104,22 @@ class ModuleSpec extends ChiselPropSpec {
   }
 
   ignore("ModuleWhenTester should return the correct result") { }
+
+  property("Forgetting a Module() wrapper should result in an error") {
+    (the [ChiselException] thrownBy {
+      elaborate { new ModuleForgetWrapper }
+    }).getMessage should include("attempted to instantiate a Module without wrapping it")
+  }
+
+  property("Double wrapping a Module should result in an error") {
+    (the [ChiselException] thrownBy {
+      elaborate { new ModuleDoubleWrap }
+    }).getMessage should include("Called Module() twice without instantiating a Module")
+  }
+
+  property("Rewrapping an already instantiated Module should result in an error") {
+    (the [ChiselException] thrownBy {
+      elaborate { new ModuleRewrap }
+    }).getMessage should include("This is probably due to rewrapping a Module instance")
+  }
 }