Added support for isolate unhandled exceptions.

sdk/lib/isolate/base.dart

Index: sdk/lib/isolate/base.dart
diff --git a/sdk/lib/isolate/base.dart b/sdk/lib/isolate/base.dart
index e43e3bbe9b0986ed4c208b6045c07cf861b58c73..1c3b43712dc074f336069f710559e58f8eff527e 100644
--- a/sdk/lib/isolate/base.dart
+++ b/sdk/lib/isolate/base.dart
@@ -32,8 +32,8 @@ external ReceivePort get port;
  * See comments at the top of this library for more details.
  */
 // Note this feature is not yet available in the dartvm.
-external SendPort spawnFunction(void topLevelFunction());
-
+external SendPort spawnFunction(void topLevelFunction(),
+    [bool UnhandledExceptionCallback(IsolateUnhandledException e)]);
 /**
  * Creates and spawns an isolate whose code is available at [uri].  Like with
  * [spawnFunction], the child isolate will have a default [ReceivePort], and a
@@ -41,7 +41,8 @@ external SendPort spawnFunction(void topLevelFunction());
  *
  * See comments at the top of this library for more details.
  */
-external SendPort spawnUri(String uri);
+external SendPort spawnUri(String uri,
+    [bool UnhandledExceptionCallback(IsolateUnhandledException e)]);
 
 /**
  * [SendPort]s are created from [ReceivePort]s. Any message sent through
@@ -142,3 +143,34 @@ abstract class SendPortSync {
   callSync(var message);
 
 }
+
+class _ReceivePortFactory {
+  external factory ReceivePort();
+}

[siva, 2012/11/21 00:45:04]

What is this change? Is it related to the UnhandledException stuff...

[Tom Ball, 2012/11/21 05:22:38]

I didn't write this, so I'm guessing it's related to the several hand-merges
I've done over the past week.  Deleted.

+
+/**
+ * Wraps unhandled exceptions thrown during isolate execution. It is
+ * used to show both the error message and the stack trace for unhandled
+ * exceptions.
+ */
+class IsolateUnhandledException implements Exception {
+  /** Message being handled when exception occurred. */
+  final message;
+
+  /** Wrapped exception. */
+  final source;
+
+  /** Trace for the wrapped exception. */
+  final Object stackTrace;
+
+  const IsolateUnhandledException(this.message, this.source, this.stackTrace);
+
+  String toString() {
+    return 'IsolateUnhandledException: exception while handling message: '
+        '${message} \n  '
+        '${source.toString().replaceAll("\n", "\n  ")}\n'
+        'original stack trace:\n  '
+        '${stackTrace.toString().replaceAll("\n","\n  ")}';
+  }
+}
+