diff -r 000000000000 -r 6474c204b198 toolkit/crashreporter/mac_utils.mm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/crashreporter/mac_utils.mm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <Foundation/Foundation.h>
+
+#include "mac_utils.h"
+#include "nsXPCOM.h"
+
+void GetObjCExceptionInfo(void* inException, nsACString& outString)
+{
+  NSException* e = (NSException*)inException;
+
+  NSString* name = [e name];
+  NSString* reason = [e reason];
+  unsigned int nameLength = [name length];
+  unsigned int reasonLength = [reason length];
+
+  unichar* nameBuffer = (unichar*)NS_Alloc(sizeof(unichar) * (nameLength + 1));
+  if (!nameBuffer)
+    return;
+  unichar* reasonBuffer = (unichar*)NS_Alloc(sizeof(unichar) * (reasonLength + 1));
+  if (!reasonBuffer) {
+    NS_Free(nameBuffer);
+    return;
+  }
+
+  [name getCharacters:nameBuffer];
+  [reason getCharacters:reasonBuffer];
+  nameBuffer[nameLength] = '\0';
+  reasonBuffer[reasonLength] = '\0';
+
+  outString.AssignLiteral("\nObj-C Exception data:\n");
+  AppendUTF16toUTF8(reinterpret_cast<const char16_t*>(nameBuffer), outString);
+  outString.AppendLiteral(": ");
+  AppendUTF16toUTF8(reinterpret_cast<const char16_t*>(reasonBuffer), outString);
+
+  NS_Free(nameBuffer);
+  NS_Free(reasonBuffer);
+}