Restored the stack traces I'd accidentally smot...

Restored the stack traces I'd accidentally smothered in r23426, and
cleaned up ObjectRunner/ScriptRunner a bit. Closes #3978, no review.

4 files changed, 47 insertions, 34 deletions

diff --git a/src/compiler/scala/tools/nsc/MainGenericRunner.scala b/src/compiler/scala/tools/nsc/MainGenericRunner.scala
index 695ce090dc..84d9eb7d22 100644
--- a/src/compiler/scala/tools/nsc/MainGenericRunner.scala
+++ b/src/compiler/scala/tools/nsc/MainGenericRunner.scala
@@ -8,7 +8,6 @@ package scala.tools.nsc
 
 import java.io.IOException
 import java.lang.{ClassNotFoundException, NoSuchMethodException}
-import java.lang.reflect.InvocationTargetException
 import java.net.{ URL, MalformedURLException }
 import scala.tools.util.PathResolver
 
@@ -21,7 +20,10 @@ import Properties.{ versionString, copyrightString }
   * or interactive entry.
   */
 object MainGenericRunner {
-  def errorFn(ex: Throwable): Boolean = errorFn(ex.toString)
+  def errorFn(ex: Throwable): Boolean = {
+    ex.printStackTrace()
+    false
+  }
   def errorFn(str: String): Boolean = {
     Console println str
     false
@@ -83,23 +85,18 @@ object MainGenericRunner {
             case "guess"  => ScalaClassLoader.classExists(classpath, thingToRun)
           }
 
-        if (isObjectName)
-          try {
-            ObjectRunner.run(classpath, thingToRun, command.arguments)
-            true
-          }
-          catch {
-            case e @ (_: ClassNotFoundException | _: NoSuchMethodException) => errorFn(e)
-            case e: InvocationTargetException => errorFn(e.getCause)
-          }
-        else
-          try {
-            ScriptRunner.runScript(settings, thingToRun, command.arguments)
+        if (isObjectName) {
+          ObjectRunner.runAndCatch(classpath, thingToRun, command.arguments) match {
+            case Left(ex) => errorFn(ex)
+            case _        => true
           }
-          catch {
-            case e: IOException       => errorFn(e.getMessage)
-            case e: SecurityException => errorFn(e)
+        }
+        else {
+          ScriptRunner.runScriptAndCatch(settings, thingToRun, command.arguments) match {
+            case Left(ex) => errorFn(ex)
+            case Right(b) => b
           }
+        }
     }
   }
 }
diff --git a/src/compiler/scala/tools/nsc/ObjectRunner.scala b/src/compiler/scala/tools/nsc/ObjectRunner.scala
index f2ddc84445..987a6b0ba0 100644
--- a/src/compiler/scala/tools/nsc/ObjectRunner.scala
+++ b/src/compiler/scala/tools/nsc/ObjectRunner.scala
@@ -8,6 +8,7 @@ package scala.tools.nsc
 
 import java.net.URL
 import util.ScalaClassLoader
+import java.lang.reflect.InvocationTargetException
 
 /** An object that runs another object specified by name.
  *
@@ -24,10 +25,22 @@ object ObjectRunner {
    *  specified classpath and argument list.
    *
    *  @throws ClassNotFoundException
-   *  @throws NoSuchMethodError
+   *  @throws NoSuchMethodException
    *  @throws InvocationTargetException
    */
   def run(urls: List[URL], objectName: String, arguments: Seq[String]) {
     (ScalaClassLoader fromURLs urls).run(objectName, arguments)
   }
+
+  /** Catches exceptions enumerated by run (in the case of InvocationTargetException,
+   *  unwrapping it) and returns it any thrown in Left(x).
+   */
+  def runAndCatch(urls: List[URL], objectName: String, arguments: Seq[String]): Either[Throwable, Unit] = {
+    try Right(run(urls, objectName, arguments))
+    catch {
+      case e: ClassNotFoundException    => Left(e)
+      case e: NoSuchMethodException     => Left(e)
+      case e: InvocationTargetException => Left(e.getCause match { case null => e ; case cause => cause })
+    }
+  }
 }
diff --git a/src/compiler/scala/tools/nsc/ScriptRunner.scala b/src/compiler/scala/tools/nsc/ScriptRunner.scala
index 23d4e32a6e..6f5f2936a8 100644
--- a/src/compiler/scala/tools/nsc/ScriptRunner.scala
+++ b/src/compiler/scala/tools/nsc/ScriptRunner.scala
@@ -13,7 +13,6 @@ import java.io.{
 }
 import java.io.{ File => JFile }
 import io.{ Directory, File, Path, PlainFile }
-import java.lang.reflect.InvocationTargetException
 import java.net.URL
 import java.util.jar.{ JarEntry, JarOutputStream }
 
@@ -250,17 +249,9 @@ object ScriptRunner {
 	  val pr = new PathResolver(settings)
 	  val classpath = File(compiledLocation).toURL +: pr.asURLs
 
-    try {
-      ObjectRunner.run(classpath, scriptMain(settings), scriptArgs)
-      true
-    }
-    catch {
-      case e @ (_: ClassNotFoundException | _: NoSuchMethodException) =>
-        Console println e
-        false
-      case e: InvocationTargetException =>
-        e.getCause.printStackTrace
-        false
+    ObjectRunner.runAndCatch(classpath, scriptMain(settings), scriptArgs) match {
+      case Left(ex) => Console println ex ; false
+      case _        => true
     }
   }
 
@@ -280,6 +271,21 @@ object ScriptRunner {
 	    throw new IOException("no such file: " + scriptFile)
   }
 
+  /** Calls runScript and catches the enumerated exceptions, routing
+   *  them to Left(ex) if thrown.
+   */
+  def runScriptAndCatch(
+    settings: GenericRunnerSettings,
+		scriptFile: String,
+		scriptArgs: List[String]): Either[Throwable, Boolean] =
+	{
+	  try Right(runScript(settings, scriptFile, scriptArgs))
+	  catch {
+	    case e: IOException       => Left(e)
+	    case e: SecurityException => Left(e)
+	  }
+  }
+
   /** Run a command
    *
    * @return true if compilation and execution succeeded, false otherwise.
diff --git a/src/library/scala/util/control/Exception.scala b/src/library/scala/util/control/Exception.scala
index 356b11df51..87aa5a9888 100644
--- a/src/library/scala/util/control/Exception.scala
+++ b/src/library/scala/util/control/Exception.scala
@@ -16,10 +16,7 @@ import collection.immutable.List
  *  @author Paul Phillips
  */
 
-import java.lang.reflect.InvocationTargetException
-
-object Exception
-{
+object Exception {
   // We get lots of crashes using this, so for now we just use Class[_]
   // type ExClass = Class[_ <: Throwable]