Refactor exceptions to remove stack trace from user errors (#1157)

1 files changed, 43 insertions, 0 deletions

diff --git a/src/main/scala/firrtl/FirrtlException.scala b/src/main/scala/firrtl/FirrtlException.scala
new file mode 100644
index 00000000..20d984a1
--- /dev/null
+++ b/src/main/scala/firrtl/FirrtlException.scala
@@ -0,0 +1,43 @@
+// See LICENSE for license details.
+
+package firrtl
+
+import scala.util.control.NoStackTrace
+
+@deprecated("External users should use either FirrtlUserException or their own hierarchy", "1.2")
+object FIRRTLException {
+  def defaultMessage(message: String, cause: Throwable) = {
+    if (message != null) {
+      message
+    } else if (cause != null) {
+      cause.toString
+    } else {
+      null
+    }
+  }
+}
+@deprecated("External users should use either FirrtlUserException or their own hierarchy", "1.2")
+class FIRRTLException(val str: String, cause: Throwable = null)
+  extends RuntimeException(FIRRTLException.defaultMessage(str, cause), cause)
+
+/** Exception indicating user error
+  *
+  * These exceptions indicate a problem due to bad input and thus do not include a stack trace.
+  * This can be extended by custom transform writers.
+  */
+class FirrtlUserException(message: String, cause: Throwable = null)
+  extends RuntimeException(message, cause) with NoStackTrace
+
+/** Wraps exceptions from CustomTransforms so they can be reported appropriately */
+case class CustomTransformException(cause: Throwable) extends Exception("", cause)
+
+/** Exception indicating something went wrong *within* Firrtl itself
+  *
+  * These exceptions indicate a problem inside the compiler and include a stack trace to help
+  * developers debug the issue.
+  *
+  * This class is private because these are issues within Firrtl itself. Exceptions thrown in custom
+  * transforms are treated differently and should thus have their own structure
+  */
+private[firrtl] class FirrtlInternalException(message: String, cause: Throwable = null)
+  extends Exception(message, cause)