Merge pull request #1158 from freechipsproject/apoptosis

Programmed Stage Death

3 files changed, 20 insertions, 0 deletions

diff --git a/src/main/scala/firrtl/options/Exceptions.scala b/src/main/scala/firrtl/options/Exceptions.scala
index 100ff464..38b2f2e2 100644
--- a/src/main/scala/firrtl/options/Exceptions.scala
+++ b/src/main/scala/firrtl/options/Exceptions.scala
@@ -18,3 +18,6 @@ class OptionsException(val message: String, cause: Throwable = null) extends Ill
   * out of order or if the compiler did not run things in the correct order.
   */
 class PhasePrerequisiteException(message: String, cause: Throwable = null) extends PhaseException(message, cause)
+
+/** Indicates that a [[Stage]] or [[Phase]] has run into a situation where it cannot continue. */
+final class StageError(val code: ExitFailure = GeneralError, cause: Throwable = null) extends Error("", cause)
diff --git a/src/main/scala/firrtl/options/ExitCodes.scala b/src/main/scala/firrtl/options/ExitCodes.scala
new file mode 100644
index 00000000..0e91fdec
--- /dev/null
+++ b/src/main/scala/firrtl/options/ExitCodes.scala
@@ -0,0 +1,15 @@
+// See LICENSE for license details.
+
+package firrtl.options
+
+/** The supertype of all exit codes */
+sealed trait ExitCode { val number: Int }
+
+/** [[ExitCode]] indicating success */
+object ExitSuccess extends ExitCode{ val number = 0 }
+
+/** An [[ExitCode]] indicative of failure. This must be non-zero and should not conflict with a reserved exit code. */
+sealed trait ExitFailure extends ExitCode
+
+/** An exit code indicating a general, non-specific error */
+object GeneralError extends ExitFailure { val number = 1 }
diff --git a/src/main/scala/firrtl/options/Stage.scala b/src/main/scala/firrtl/options/Stage.scala
index f2780761..3752b846 100644
--- a/src/main/scala/firrtl/options/Stage.scala
+++ b/src/main/scala/firrtl/options/Stage.scala
@@ -69,6 +69,8 @@ class StageMain(val stage: Stage) {
   final def main(args: Array[String]): Unit = try {
     stage.execute(args, Seq.empty)
   } catch {
+    case a: StageError =>
+      System.exit(a.code.number)
     case a: OptionsException =>
       StageUtils.dramaticUsageError(a.message)
       System.exit(1)