Throw exceptions for cloneType failures - fix #358

Add a Builder.exception() method for those cases where continuing is likely to mask the initial error.

3 files changed, 69 insertions, 2 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala b/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
index de7af462..68fe0bb5 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
@@ -408,12 +408,12 @@ class Bundle extends Aggregate {
           constructor.newInstance(_parent.get).asInstanceOf[this.type]
         } catch {
           case _: java.lang.reflect.InvocationTargetException | _: java.lang.IllegalArgumentException =>
-            Builder.error(s"Parameterized Bundle ${this.getClass} needs cloneType method. You are probably using " +
+            Builder.exception(s"Parameterized Bundle ${this.getClass} needs cloneType method. You are probably using " +
               "an anonymous Bundle object that captures external state and hence is un-cloneTypeable")
             this
         }
       case _: java.lang.reflect.InvocationTargetException | _: java.lang.IllegalArgumentException =>
-        Builder.error(s"Parameterized Bundle ${this.getClass} needs cloneType method")
+        Builder.exception(s"Parameterized Bundle ${this.getClass} needs cloneType method")
         this
     }
   }
diff --git a/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala b/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala
index b4b0e028..32ba248c 100644
--- a/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala
+++ b/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala
@@ -188,6 +188,16 @@ private[chisel3] object Builder {
   def warning(m: => String): Unit = errors.warning(m)
   def deprecated(m: => String): Unit = errors.deprecated(m)
 
+  /** Record an exception as an error, and throw it.
+    *
+    * @param m exception message
+    */
+  @throws(classOf[ChiselException])
+  def exception(m: => String): Unit = {
+    error(m)
+    throwException(m)
+  }
+
   def build[T <: Module](f: => T): Circuit = {
     dynamicContextVar.withValue(Some(new DynamicContext())) {
       errors.info("Elaborating design...")
diff --git a/src/test/scala/chiselTests/MissingCloneBindingExceptionSpec.scala b/src/test/scala/chiselTests/MissingCloneBindingExceptionSpec.scala
new file mode 100644
index 00000000..fd48206e
--- /dev/null
+++ b/src/test/scala/chiselTests/MissingCloneBindingExceptionSpec.scala
@@ -0,0 +1,57 @@
+// See LICENSE for license details.
+
+package chiselTests
+import Chisel.ChiselException
+import org.scalatest._
+
+class MissingCloneBindingExceptionSpec extends FlatSpec with Matchers {
+  behavior of "missing cloneType in Chisel3"
+  ( the[ChiselException] thrownBy {
+    import chisel3._
+
+    class TestIO(w: Int) extends Bundle {
+      val a = Vec(4, UInt(width = w)).asInput
+
+      //override def cloneType = (new TestIO(w)).asInstanceOf[this.type]
+    }
+
+    class Test extends Module {
+      val io = IO(new TestIO(32))
+    }
+
+    class TestTop extends Module {
+      val io = IO(new Bundle {})
+
+      val subs = Vec.fill(2) {
+        Module(new Test).io
+      }
+    }
+
+    val dummy = new TestTop
+  }).getMessage should include("needs cloneType method")
+
+  behavior of "missing cloneType in Chisel2"
+  ( the[ChiselException] thrownBy {
+    import Chisel._
+
+    class TestIO(w: Int) extends Bundle {
+      val a = Vec(4, UInt(width = w)).asInput
+
+      //override def cloneType = (new TestIO(w)).asInstanceOf[this.type]
+    }
+
+    class Test extends Module {
+      val io = IO(new TestIO(32))
+    }
+
+    class TestTop extends Module {
+      val io = IO(new Bundle {})
+
+      val subs = Vec.fill(2) {
+        Module(new Test).io
+      }
+    }
+
+    val dummy = new TestTop
+  }).getMessage should include("needs cloneType method")
+}