In Classic mode during debugging now script error contains a full stack trace

Author: Taritsyn

NuGet/MsieJavaScriptEngine.nuspec

@@ -12,7 +12,8 @@
 		<requireLicenseAcceptance>false</requireLicenseAcceptance>
 		<description>This library is a .NET wrapper for working with the JavaScript engines of Internet Explorer and Edge (JsRT versions of Chakra, ActiveScript version of Chakra and Classic JavaScript Engine). Project was based on the code of SassAndCoffee.JavaScript (http://github.com/paulcbetts/SassAndCoffee), Chakra Sample Hosts (http://github.com/panopticoncentral/chakra-host) and jsrt-dotnet (http://github.com/robpaveza/jsrt-dotnet).</description>
 		<summary>This library is a .NET wrapper for working with the JavaScript engines of Internet Explorer and Edge (JsRT versions of Chakra, ActiveScript version of Chakra and Classic JavaScript Engine).</summary>
-		<releaseNotes>In ActiveScript modes now are uses the short names of error categories.</releaseNotes>
+		<releaseNotes>1. In ActiveScript modes now are uses the short names of error categories;
+2. In `Classic` mode during debugging now script error contains a full stack trace.</releaseNotes>
 		<copyright>Copyright (c) 2012-2017 Andrey Taritsyn - http://www.taritsyn.ru</copyright>
 		<language>en-US</language>
 		<tags>JavaScript ECMAScript MSIE IE Edge Chakra</tags>

NuGet/readme.txt

@@ -21,7 +21,9 @@
    =============
    RELEASE NOTES
    =============
-   In ActiveScript modes now are uses the short names of error categories.
+   1. In ActiveScript modes now are uses the short names of error categories;
+   2. In `Classic` mode during debugging now script error contains a full stack
+      trace.
 
    ============
    PROJECT SITE

src/MsieJavaScriptEngine.Net4/MsieJavaScriptEngine.Net40.csproj

@@ -165,6 +165,12 @@
     <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\IDebugStackFrameSniffer.cs">
       <Link>ActiveScript\Debugging\IDebugStackFrameSniffer.cs</Link>
     </Compile>
+    <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\IDebugStackFrameSnifferEx32.cs">
+      <Link>ActiveScript\Debugging\IDebugStackFrameSnifferEx32.cs</Link>
+    </Compile>
+    <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\IDebugStackFrameSnifferEx64.cs">
+      <Link>ActiveScript\Debugging\IDebugStackFrameSnifferEx64.cs</Link>
+    </Compile>
     <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\IDebugSyncOperation.cs">
       <Link>ActiveScript\Debugging\IDebugSyncOperation.cs</Link>
     </Compile>
@@ -201,6 +207,9 @@
     <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\IRemoteDebugApplicationThread.cs">
       <Link>ActiveScript\Debugging\IRemoteDebugApplicationThread.cs</Link>
     </Compile>
+    <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\NullEnumDebugStackFrames.cs">
+      <Link>ActiveScript\Debugging\NullEnumDebugStackFrames.cs</Link>
+    </Compile>
     <Compile Include="..\MsieJavaScriptEngine\ActiveScript\Debugging\ProcessDebugManager.cs">
       <Link>ActiveScript\Debugging\ProcessDebugManager.cs</Link>
     </Compile>
@@ -495,6 +504,9 @@
     <Compile Include="..\MsieJavaScriptEngine\Undefined.cs">
       <Link>Undefined.cs</Link>
     </Compile>
+    <Compile Include="..\MsieJavaScriptEngine\Utilities\CharExtensions.cs">
+      <Link>Utilities\CharExtensions.cs</Link>
+    </Compile>
     <Compile Include="..\MsieJavaScriptEngine\Utilities\StringBuilderExtensions.cs">
       <Link>Utilities\StringBuilderExtensions.cs</Link>
     </Compile>

src/MsieJavaScriptEngine/ActiveScript/ActiveScriptJsEngineBase.ScriptSite.cs

@@ -2,11 +2,13 @@
 using System;
 using System.Globalization;
 using System.Runtime.InteropServices;
+using System.Text;
 
 using EXCEPINFO = System.Runtime.InteropServices.ComTypes.EXCEPINFO;
 
 using MsieJavaScriptEngine.ActiveScript.Debugging;
 using MsieJavaScriptEngine.Constants;
+using MsieJavaScriptEngine.Helpers;
 using MsieJavaScriptEngine.Resources;
 
 namespace MsieJavaScriptEngine.ActiveScript
@@ -44,15 +46,44 @@ private string GetErrorDetails(IActiveScriptError error)
 				EXCEPINFO excepInfo;
 				error.GetExceptionInfo(out excepInfo);
 
-				string errorDetails = string.Format("{0}: {1}",
+				string errorDetails;
+				string message = string.Format("{0}: {1}",
 					_jsEngine.ShortenErrorCategoryName(excepInfo.bstrSource), excepInfo.bstrDescription);
+
 				if (_jsEngine._processDebugManagerWrapper != null)
 				{
-					string errorLocation = GetErrorLocation(error);
-					if (!string.IsNullOrWhiteSpace(errorLocation))
+					bool isSyntaxError = false;
+
+					if (ComHelpers.HResult.GetFacility(excepInfo.scode) == ComHelpers.HResult.FACILITY_CONTROL)
+					{
+						int errorCode = ComHelpers.HResult.GetCode(excepInfo.scode);
+						isSyntaxError = errorCode >= 1002 && errorCode <= 1035;
+					}
+
+					var errorBuilder = new StringBuilder(message);
+					string stackTrace = !isSyntaxError ? _jsEngine.GetStackTrace() : string.Empty;
+
+					if (!string.IsNullOrWhiteSpace(stackTrace))
 					{
-						errorDetails += Environment.NewLine + errorLocation;
+						errorBuilder.AppendLine();
+						errorBuilder.Append(stackTrace);
 					}
+					else
+					{
+						string errorLocation = GetErrorLocation(error);
+						if (!string.IsNullOrWhiteSpace(errorLocation))
+						{
+							errorBuilder.AppendLine();
+							errorBuilder.Append(errorLocation);
+						}
+					}
+
+					errorDetails = errorBuilder.ToString();
+					errorBuilder.Clear();
+				}
+				else
+				{
+					errorDetails = message;
 				}
 
 				return errorDetails;

src/MsieJavaScriptEngine/ActiveScript/ActiveScriptJsEngineBase.cs

@@ -5,6 +5,7 @@
 using System.Reflection;
 using System.Runtime.InteropServices;
 using System.Runtime.InteropServices.Expando;
+using System.Text;
 
 using MsieJavaScriptEngine.ActiveScript.Debugging;
 using MsieJavaScriptEngine.Constants;
@@ -88,7 +89,7 @@ internal abstract partial class ActiveScriptJsEngineBase : InnerJsEngineBase
 		/// <summary>
 		/// Prefix of error category name
 		/// </summary>
-		private string _errorCategoryNamePrefix;
+		private readonly string _errorCategoryNamePrefix;
 
 
 		/// <summary>
@@ -364,6 +365,100 @@ private void ThrowError()
 			}
 		}
 
+		/// <summary>
+		/// Gets a string representation of the script call stack
+		/// </summary>
+		/// <returns>The script call stack formatted as a string</returns>
+		private string GetStackTrace()
+		{
+			StringBuilder stackTraceBuilder = null;
+
+			IEnumDebugStackFrames enumFrames;
+			_activeScriptWrapper.EnumStackFrames(out enumFrames);
+
+			while (true)
+			{
+				DebugStackFrameDescriptor descriptor;
+				uint countFetched;
+				enumFrames.Next(1, out descriptor, out countFetched);
+				if (countFetched < 1)
+				{
+					break;
+				}
+
+				if (stackTraceBuilder == null)
+				{
+					stackTraceBuilder = new StringBuilder();
+				}
+
+				try
+				{
+					IDebugStackFrame stackFrame = descriptor.Frame;
+
+					string description;
+					stackFrame.GetDescriptionString(true, out description);
+
+					if (string.Equals(description, "JScript global code", StringComparison.Ordinal))
+					{
+						description = "Global code";
+					}
+
+					IDebugCodeContext codeContext;
+					stackFrame.GetCodeContext(out codeContext);
+
+					IDebugDocumentContext documentContext;
+					codeContext.GetDocumentContext(out documentContext);
+
+					if (documentContext == null)
+					{
+						stackTraceBuilder.AppendFormatLine("   at {0}", description);
+					}
+					else
+					{
+						IDebugDocument document;
+						documentContext.GetDocument(out document);
+
+						string documentName;
+						document.GetName(DocumentNameType.Title, out documentName);
+
+						var documentText = (IDebugDocumentText)document;
+
+						uint position;
+						uint length;
+						documentText.GetPositionOfContext(documentContext, out position, out length);
+
+						uint lineNumber;
+						uint offsetInLine;
+						documentText.GetLineOfPosition(position, out lineNumber, out offsetInLine);
+						uint columnNumber = offsetInLine + 1;
+
+						stackTraceBuilder.AppendFormatLine("   at {0} ({1}:{2}:{3})", description, documentName,
+							lineNumber, columnNumber);
+					}
+				}
+				finally
+				{
+					if (descriptor.pFinalObject != IntPtr.Zero)
+					{
+						Marshal.Release(descriptor.pFinalObject);
+					}
+				}
+			}
+
+			string stackTrace;
+			if (stackTraceBuilder != null)
+			{
+				stackTrace = stackTraceBuilder.TrimEnd().ToString();
+				stackTraceBuilder.Clear();
+			}
+			else
+			{
+				stackTrace = string.Empty;
+			}
+
+			return stackTrace;
+		}
+
 		/// <summary>
 		/// Executes a script text
 		/// </summary>

src/MsieJavaScriptEngine/ActiveScript/ActiveScriptWrapper.cs

@@ -52,6 +52,16 @@ internal sealed class ActiveScriptWrapper
 		/// </summary>
 		private IntPtr _pActiveScriptGarbageCollector;
 
+		/// <summary>
+		/// Pointer to an instance of 32-bit debug stack frame sniffer
+		/// </summary>
+		private IntPtr _pDebugStackFrameSniffer32;
+
+		/// <summary>
+		/// Pointer to an instance of 64-bit debug stack frame sniffer
+		/// </summary>
+		private IntPtr _pDebugStackFrameSniffer64;
+
 		/// <summary>
 		/// Instance of Active Script engine
 		/// </summary>
@@ -72,6 +82,16 @@ internal sealed class ActiveScriptWrapper
 		/// </summary>
 		private IActiveScriptGarbageCollector _activeScriptGarbageCollector;
 
+		/// <summary>
+		/// Instance of 32-bit debug stack frame sniffer
+		/// </summary>
+		private IDebugStackFrameSnifferEx32 _debugStackFrameSniffer32;
+
+		/// <summary>
+		/// Instance of 64-bit debug stack frame sniffer
+		/// </summary>
+		private IDebugStackFrameSnifferEx64 _debugStackFrameSniffer64;
+
 		/// <summary>
 		/// Last COM exception
 		/// </summary>
@@ -105,22 +125,28 @@ public ActiveScriptWrapper(string clsid, ScriptLanguageVersion languageVersion)
 			{
 				_pActiveScriptParse64 = ComHelpers.QueryInterface<IActiveScriptParse64>(_pActiveScript);
 				_pActiveScriptDebug64 = ComHelpers.QueryInterface<IActiveScriptDebug64>(_pActiveScript);
+				_pDebugStackFrameSniffer64 = ComHelpers.QueryInterfaceNoThrow<IDebugStackFrameSnifferEx64>(_pActiveScript);
 			}
 			else
 			{
 				_pActiveScriptParse32 = ComHelpers.QueryInterface<IActiveScriptParse32>(_pActiveScript);
 				_pActiveScriptDebug32 = ComHelpers.QueryInterface<IActiveScriptDebug32>(_pActiveScript);
+				_pDebugStackFrameSniffer32 = ComHelpers.QueryInterfaceNoThrow<IDebugStackFrameSnifferEx32>(_pActiveScript);
 			}
 			_pActiveScriptGarbageCollector = ComHelpers.QueryInterfaceNoThrow<IActiveScriptGarbageCollector>(_pActiveScript);
 
 			_activeScript = (IActiveScript)Marshal.GetObjectForIUnknown(_pActiveScript);
 			if (_is64Bit)
 			{
 				_activeScriptParse64 = (IActiveScriptParse64)_activeScript;
+				_debugStackFrameSniffer64 = _pDebugStackFrameSniffer64 != IntPtr.Zero ?
+					_activeScript as IDebugStackFrameSnifferEx64 : null;
 			}
 			else
 			{
 				_activeScriptParse32 = (IActiveScriptParse32)_activeScript;
+				_debugStackFrameSniffer32 = _pDebugStackFrameSniffer32 != IntPtr.Zero ?
+					_activeScript as IDebugStackFrameSnifferEx32 : null;
 			}
 			_activeScriptGarbageCollector = _activeScript as IActiveScriptGarbageCollector;
 
@@ -301,6 +327,31 @@ public void EnumCodeContextsOfPosition(UIntPtr sourceContext, uint offset, uint
 			ComHelpers.HResult.Check(result);
 		}
 
+		public void EnumStackFrames(out IEnumDebugStackFrames enumFrames)
+		{
+			enumFrames = null;
+
+			if (_is64Bit)
+			{
+				if (_debugStackFrameSniffer64 != null)
+				{
+					_debugStackFrameSniffer64.EnumStackFrames(out enumFrames);
+				}
+			}
+			else
+			{
+				if (_debugStackFrameSniffer32 != null)
+				{
+					_debugStackFrameSniffer32.EnumStackFrames(out enumFrames);
+				}
+			}
+
+			if (enumFrames == null)
+			{
+				enumFrames = new NullEnumDebugStackFrames();
+			}
+		}
+
 		/// <summary>
 		/// The Active Script host calls this method to start garbage collection
 		/// </summary>
@@ -325,21 +376,25 @@ public void Dispose()
 				_activeScriptGarbageCollector = null;
 				if (_is64Bit)
 				{
+					_debugStackFrameSniffer64 = null;
 					_activeScriptParse64 = null;
 				}
 				else
 				{
+					_debugStackFrameSniffer32 = null;
 					_activeScriptParse32 = null;
 				}
 
 				ComHelpers.ReleaseAndEmpty(ref _pActiveScriptGarbageCollector);
 				if (_is64Bit)
 				{
+					ComHelpers.ReleaseAndEmpty(ref _pDebugStackFrameSniffer64);
 					ComHelpers.ReleaseAndEmpty(ref _pActiveScriptDebug64);
 					ComHelpers.ReleaseAndEmpty(ref _pActiveScriptParse64);
 				}
 				else
 				{
+					ComHelpers.ReleaseAndEmpty(ref _pDebugStackFrameSniffer32);
 					ComHelpers.ReleaseAndEmpty(ref _pActiveScriptDebug32);
 					ComHelpers.ReleaseAndEmpty(ref _pActiveScriptParse32);
 				}

src/MsieJavaScriptEngine/ActiveScript/Debugging/IDebugStackFrameSnifferEx32.cs

@@ -0,0 +1,34 @@
+#if !NETSTANDARD1_3
+using System.Runtime.InteropServices;
+
+namespace MsieJavaScriptEngine.ActiveScript.Debugging
+{
+	/// <summary>
+	/// Provides a way to enumerate the logical stack frames known by a component. Script engines typically
+	/// implement this interface. The process debug manager uses this interface to find all stack frames
+	/// associated with a given thread.
+	/// </summary>
+	[ComImport]
+	[Guid("51973c19-cb0c-11d0-b5c9-00a0244a0e7a")]
+	[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+	internal interface IDebugStackFrameSnifferEx32 // : IDebugStackFrameSniffer
+	{
+		#region IDebugStackFrameSniffer methods
+
+		/// <summary>
+		/// Returns an enumerator of stack frames for the current thread
+		/// </summary>
+		/// <param name="enumFrames">Enumerator of stack frames for the current thread</param>
+		void EnumStackFrames(
+			[Out] [MarshalAs(UnmanagedType.Interface)] out IEnumDebugStackFrames enumFrames
+		);
+
+		#endregion
+
+		void EnumStackFramesEx32(
+			[In] uint minimum,
+			[Out] [MarshalAs(UnmanagedType.Interface)] out IEnumDebugStackFrames enumFrames
+		);
+	}
+}
+#endif