SharpDevelop Community

While debugging, SharpDevelop throws an exception each time, I hover any source line with the expression

myTocData.arTrackData[bTrack]

if 'arTrackData' is null. E.g. within the line

  var addr = BitConverter.GetBytes(myTocData.arTrackData[bTrack].Address);

it is possible to hover 'myTocData' and to open the member list in the tooltip by clicking the '+'. It is also possible to hover 'bTrack'. But touching 'Address' or 'arTrackData' leads to an exception, when the tooltip is going to be displayed.

The arTrackData member of myTocData is a TrackDataArray, which is a class with an indexer:

  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
  protected sealed class TrackDataArray 
  { 
     // ...

     public TRACK_DATA this[int iIdx]
     {
        get
        {
           if((iIdx<0) || (iIdx>=CdDevice.MAXIMUM_NUMBER_TRACKS))
              throw new IndexOutOfRangeException();

      //...

And here's the message:

SharpDevelop Version : 3.0.0.3800
.NET Version : 2.0.50727.3053
OS Version : Microsoft Windows NT 5.1.2600 Service Pack 3
Current culture : German (Germany) (de-DE)
Current UI language : en
Working Set Memory : 138272kb
GC Heap Memory : 29466kb

Error while requesting tooltip for location (Line 111, Col 52)
Exception thrown:
System.InvalidCastException: Specified cast is not valid.
  at Debugger.AddIn.EvaluateAstVisitor.VisitIndexerExpression(IndexerExpression indexerExpression, Object data)
  at ICSharpCode.NRefactory.Ast.IndexerExpression.AcceptVisitor(IAstVisitor visitor, Object data)
  at Debugger.AddIn.AstEvaluator.Evaluate(String code, SupportedLanguage language, StackFrame context)
  at ICSharpCode.SharpDevelop.Services.WindowsDebugger.GetValueFromName(String variableName)
  at ICSharpCode.SharpDevelop.Services.WindowsDebugger.GetValueAsString(String variableName)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetMemberText(IAmbience ambience, IEntity member, String expression, Boolean& debuggerCanShowValue)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetText(ResolveResult result, String expression, Boolean& debuggerCanShowValue)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetToolTipInfo(TextArea textArea, ToolTipRequestEventArgs e)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerTextAreaToolTipProvider.GetToolTipInfo(TextArea textArea, ToolTipRequestEventArgs e)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.TextAreaToolTipRequest(Object sender, ToolTipRequestEventArgs e)

---- Recent log messages:
22:22:09.765 [1] DEBUG - ActiveViewContentChanged to [TextEditorDisplayBindingWrapper D:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs]
22:22:09.765 [1] DEBUG - ActiveContentChanged to [TextEditorDisplayBindingWrapper D:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs]
22:22:09.765 [1] DEBUG - UpdateSelectedObjectIfActive
22:22:09.765 [1] DEBUG - NavigationService -- resume logging
22:22:09.765 [1] INFO - FileService
 Jumped to File Position: [d:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs : 111x3]
22:22:09.781 [1] DEBUG - Debugger: Callback: ExceptionUnwind
22:22:09.890 [1] DEBUG - Debugger: Callback: EvalComplete
22:22:10.062 [1] DEBUG - Debugger: Expression cache cleared
22:22:10.078 [1] DEBUG - Debugger: Callback: EvalComplete
22:22:10.140 [1] INFO - Repainting Local Variables Pad (0.8831 ms)
22:22:19.343 [1] DEBUG - Debugger: Debugger event: OnPaused()
22:22:19.343 [1] INFO - Jump to current line - start
22:22:19.343 [1] INFO - FileService
 Jumping to File Position: [d:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs : 111x3]
22:22:19.343 [1] DEBUG - NavigationService -- suspend logging
22:22:19.343 [1] INFO - Open file d:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs
22:22:19.343 [1] DEBUG - NavigationService -- resume logging
22:22:19.343 [1] INFO - FileService
 Jumped to File Position: [d:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs : 111x3]
22:22:19.343 [1] INFO - Jump to current line - end (2.7205 ms)
22:22:19.343 [1] INFO - Callstack refresh - start
22:22:19.578 [1] INFO - Callstack refresh - end (221.8126 ms)
22:22:24.562 [1] INFO - asking debugger for value of 'myTocData'
22:22:24.562 [1] DEBUG - Debugger: Callback: EvalComplete
22:22:27.859 [1] INFO - asking debugger for value of 'myTocData.arTrackData[bTrack]'
22:22:27.875 [1] ERROR - Error while requesting tooltip for location (Line 111, Col 52)
--> Exception:
System.InvalidCastException: Specified cast is not valid.
  at Debugger.AddIn.EvaluateAstVisitor.VisitIndexerExpression(IndexerExpression indexerExpression, Object data)
  at ICSharpCode.NRefactory.Ast.IndexerExpression.AcceptVisitor(IAstVisitor visitor, Object data)
  at Debugger.AddIn.AstEvaluator.Evaluate(String code, SupportedLanguage language, StackFrame context)
  at ICSharpCode.SharpDevelop.Services.WindowsDebugger.GetValueFromName(String variableName)
  at ICSharpCode.SharpDevelop.Services.WindowsDebugger.GetValueAsString(String variableName)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetMemberText(IAmbience ambience, IEntity member, String expression, Boolean& debuggerCanShowValue)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetText(ResolveResult result, String expression, Boolean& debuggerCanShowValue)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.GetToolTipInfo(TextArea textArea, ToolTipRequestEventArgs e)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerTextAreaToolTipProvider.GetToolTipInfo(TextArea textArea, ToolTipRequestEventArgs e)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.TextAreaToolTipRequest(Object sender, ToolTipRequestEventArgs e)
22:22:27.937 [1] WARN - Stack trace of last error log:
  at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
  at System.Environment.get_StackTrace()
  at ICSharpCode.Core.MessageService.ShowError(Exception ex, String message)
  at ICSharpCode.SharpDevelop.Debugging.DebuggerService.TextAreaToolTipRequest(Object sender, ToolTipRequestEventArgs e)
  at ICSharpCode.TextEditor.ToolTipRequestEventHandler.Invoke(Object sender, ToolTipRequestEventArgs e)
  at ICSharpCode.TextEditor.TextArea.OnToolTipRequest(ToolTipRequestEventArgs e)
  at ICSharpCode.TextEditor.TextArea.RequestToolTip(Point mousePos)
  at ICSharpCode.TextEditor.TextArea.OnMouseHover(EventArgs e)
  at System.Windows.Forms.Control.WmMouseHover(Message& m)
  at System.Windows.Forms.Control.WndProc(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
  at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
  at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
  at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
  at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
  at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
  at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
  at System.Windows.Forms.Application.Run(Form mainForm)
  at ICSharpCode.SharpDevelop.Commands.StartWorkbenchCommand.Run(IList`1 fileList)
  at ICSharpCode.SharpDevelop.Sda.CallHelper.RunWorkbenchInternal(Object settings)
  at ICSharpCode.SharpDevelop.Sda.CallHelper.RunWorkbench(WorkbenchSettings settings)
  at ICSharpCode.SharpDevelop.Sda.SharpDevelopHost.RunWorkbench(WorkbenchSettings settings)
  at ICSharpCode.SharpDevelop.SharpDevelopMain.RunApplication()
  at ICSharpCode.SharpDevelop.SharpDevelopMain.Run(String[ args)
  at ICSharpCode.SharpDevelop.SharpDevelopMain.Main(String[ args)

---- Post-error application state information:
Installed 3rd party AddIns: 
Workbench.ActiveContent: [TextEditorDisplayBindingWrapper D:\Projekte\SharpDevelop\HyperTest\HyperTest\CdToc.cs]
ProjectService.OpenSolution: [Solution: FileName=D:\Projekte\SharpDevelop\HyperTest\HyperTest.sln, HasProjects=True, ReadOnly=False]
ProjectService.CurrentProject: [CSharpProject: HyperTest]

Do you have a small example app that reproduces this issue?

What are your debugger settings (Tools > Options > Debugger)?

Sorry, app is not that small. I tried to reduce it, but I could not compile or otherwise reproduce error then. Since I do not know, how to post a complete project zip here, I just paste the cs, where it happens.

The source line causing the xcpt is on the bottom:

  trk.uBCDAddress=myTocData.arTrackData[bTrack].Address;

And my debugger options are

Use "just my code" ...: yes

Step over code w/o symbols: yes

Step over code marked with dbg attribs: yes

Step over all properties: no

Step over single line properties: no

Step over field access properties: yes

Thanks in advance

 Here comes the code:

using System;
using System.Runtime.InteropServices;

namespace HyperTest
{
 /// <summary>
 /// Description of CdToc.
 /// </summary>
 ///

 [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]  
 public class CdToc
 {
  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
  protected struct TRACK_DATA
  {
  public byte Reserved;
  public byte bitVector;
  public byte Control
  {
  get { return ((byte)((this.bitVector & 15u))); }
  set { this.bitVector = ((byte)((value | this.bitVector))); }
  }
   
  public byte Adr
  {
  get { return ((byte)(((this.bitVector & 240u) / 16))); }
  set { this.bitVector = ((byte)(((value * 16) | this.bitVector))); }
  }
   
  public byte TrackNumber;
  public byte Reserved1;
  public uint Address;
   
  }
 
  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
  protected sealed class TrackDataArray
  {
  internal TrackDataArray()
  {
  abData=new byte[CdDevice.MAXIMUM_NUMBER_TRACKS*Marshal.SizeOf(typeof(TRACK_DATA))];
  }
   
  [MarshalAs(UnmanagedType.ByValArray,SizeConst=CdDevice.MAXIMUM_NUMBER_TRACKS*8)]
  private byte[ abData;
  public TRACK_DATA this[byte bIdx]
  {
  get
  {
  if((bIdx<1) || (bIdx>CdDevice.MAXIMUM_NUMBER_TRACKS))
  throw new IndexOutOfRangeException();
   
  TRACK_DATA res;
  var hData=GCHandle.Alloc(abData,GCHandleType.Pinned);  
  try
  {  
  var buffer=hData.AddrOfPinnedObject();
  buffer=(IntPtr)(buffer.ToInt32()+((bIdx-1)*Marshal.SizeOf(typeof(TRACK_DATA))));
  res=(TRACK_DATA)Marshal.PtrToStructure(buffer,typeof(TRACK_DATA));  
  }
  finally
  {  
  hData.Free();  
  }  
  return res;  
  }
  }  
  }
   
  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
  protected sealed class TocData
  {
  public ushort wLength;
  public byte bFirstTrack;
  public byte bLastTrack;
  public TrackDataArray arTrackData;
  }
 
  protected CdDevice myDevice;
  protected TocData myTocData;

  protected TRACK_DATA myTrackData(byte bTrack)
  {
  if((bTrack<1) || (bTrack>myTocData.bLastTrack))
  throw new IndexOutOfRangeException();
  return myTocData.arTrackData[bTrack];
  }
 
  public byte FirstTrack
  {
  get { return myTocData.bFirstTrack; }
  private set { myTocData.bFirstTrack=value; }
  }
 
  public byte LastTrack
  {
  get { return myTocData.bLastTrack; }
  private set { myTocData.bLastTrack=value; }
  }
 
  public CdToc(CdDevice cdr)
  {
  myDevice=cdr;
  myTocData=new TocData();
  }
 
  public void update()
  {
  uint uBytesRead=0;
  int iErr=0;

  //var uSizeToc=(int)(Marshal.SizeOf(myTocData)+CdDevice.MAXIMUM_NUMBER_TRACKS*Marshal.SizeOf(typeof(TRACK_DATA)));
  var uSizeToc=64000;
  myTocData.wLength=(ushort)Marshal.SizeOf(myTocData);
  var hTOC=Marshal.AllocHGlobal(uSizeToc);
  try
  {
  Marshal.StructureToPtr(myTocData,hTOC,true);
  if(0==(iErr=myDevice.IoControl(CdIoCtl.READ_TOC,IntPtr.Zero,
  0,hTOC,(uint)uSizeToc,out uBytesRead,IntPtr.Zero)))
  Marshal.PtrToStructure(hTOC,myTocData);
  }
  finally
  {
  Marshal.FreeHGlobal(hTOC);
  }
  }
 
  public CdTrack getTrack(byte bTrack)
  {
  if((bTrack<1) || (bTrack>myTocData.bLastTrack))
  throw new IndexOutOfRangeException();
   
  CdTrack trk=new CdTrack(myDevice,bTrack);  
  trk.uBCDAddress=myTocData.arTrackData[bTrack].Address;
  return trk;
  }
 }
}