From fc9f33acdafa20139854da6af8e9351694c92eee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Pedro?= <jpedrolmail@gmail.com>
Date: Sun, 18 Jun 2017 02:04:59 +0100
Subject: [PATCH] Improved the NullReferenceException message.

---
 source/Cosmos.Debug.Symbols/DebugInfo.cs      |  5 ++++
 .../AD7.Impl/AD7Process.cs                    | 25 +++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/source/Cosmos.Debug.Symbols/DebugInfo.cs b/source/Cosmos.Debug.Symbols/DebugInfo.cs
index d50db1a1c..8b664201d 100644
--- a/source/Cosmos.Debug.Symbols/DebugInfo.cs
+++ b/source/Cosmos.Debug.Symbols/DebugInfo.cs
@@ -772,6 +772,11 @@ namespace Cosmos.Debug.Symbols
             return address;
         }
 
+        public Document GetDocumentById(long aDocumentId)
+        {
+            return mConnection.Get<Document>(aDocumentId);
+        }
+        
         public MethodIlOp GetFirstMethodIlOpByMethodIdAndILOffset(long aMethodId, long aILOffset)
         {
             //Debug("GetFirstMethodIlOpByMethodIdAndILOffset. MethodID = {0}, ILOffset = 0x{1}", aMethodId, aILOffset.ToString("X4"));
diff --git a/source/Cosmos.VS.DebugEngine/AD7.Impl/AD7Process.cs b/source/Cosmos.VS.DebugEngine/AD7.Impl/AD7Process.cs
index 0d8e74a21..4255c7a59 100644
--- a/source/Cosmos.VS.DebugEngine/AD7.Impl/AD7Process.cs
+++ b/source/Cosmos.VS.DebugEngine/AD7.Impl/AD7Process.cs
@@ -381,6 +381,27 @@ namespace Cosmos.VS.DebugEngine.AD7.Impl
 
         private void DbgCmdNullReferenceOccurred(uint lastEIPAddress)
         {
+            if (mDebugInfo.TryGetValue(BuildPropertyNames.DebugModeString, out var xDebugMode))
+            {
+                if (xDebugMode == "Source")
+                {
+                    try
+                    {
+                        var xMethod = mDebugInfoDb.GetMethod(lastEIPAddress);
+                        var xLabel = mDebugInfoDb.GetLabels(lastEIPAddress)[0];
+                        var xMethodIlOp = mDebugInfoDb.TryGetFirstMethodIlOpByLabelName(xLabel.Remove(xLabel.LastIndexOf('.'))).IlOffset;
+                        var xSequencePoints = mDebugInfoDb.GetSequencePoints(mDebugInfoDb.GetAssemblyFileById(xMethod.AssemblyFileID).Pathname, xMethod.MethodToken);
+                        var xLine = xSequencePoints.Where(q => q.Offset <= xMethodIlOp).Last().LineStart;
+
+                        AD7Util.MessageBox($"NullReferenceException occurred in '{xMethod.LabelCall}'{Environment.NewLine}Document: {mDebugInfoDb.GetDocumentById(xMethod.DocumentID)}{Environment.NewLine}Line: {xLine}{Environment.NewLine}Address: 0x{lastEIPAddress.ToString("X8")}");
+                        return;
+                    }
+                    catch (InvalidOperationException)
+                    {
+                    }
+                }
+            }
+
             AD7Util.MessageBox(String.Format("NullReferenceException occurred at address 0x{0:X8}! Halting now.", lastEIPAddress));
         }
 
@@ -427,7 +448,7 @@ namespace Cosmos.VS.DebugEngine.AD7.Impl
             switch (mLaunch)
             {
                 case LaunchType.VMware:
-#region CheckIfHyperVServiceIsRunning
+                    #region CheckIfHyperVServiceIsRunning
 
                     using (System.ServiceProcess.ServiceController sc = new System.ServiceProcess.ServiceController("vmms"))
                     {
@@ -447,7 +468,7 @@ namespace Cosmos.VS.DebugEngine.AD7.Impl
                         }
                     }
 
-#endregion CheckIfHyperVServiceIsRunning
+                    #endregion CheckIfHyperVServiceIsRunning
 
                     mHost = new VMware(mDebugInfo, xUseGDB);
                     break;