Debugger: Improved performance when a lot of labels are defined (e.g 1000+)

Core/LabelManager.cpp

@@ -8,6 +8,13 @@ LabelManager::LabelManager(shared_ptr<BaseMapper> mapper)
 	_mapper = mapper;
 }
 
+void LabelManager::DeleteLabels()
+{
+	_codeComments.clear();
+	_codeLabels.clear();
+	_codeLabelReverseLookup.clear();
+}
+
 void LabelManager::SetLabel(uint32_t address, AddressType addressType, string label, string comment)
 {
 	address = GetLabelAddress(address, addressType);

Core/LabelManager.h

@@ -33,6 +33,7 @@ public:
 	LabelManager(shared_ptr<BaseMapper> mapper);
 
 	void SetLabel(uint32_t address, AddressType addressType, string label, string comment);
+	void DeleteLabels();
 
 	int32_t GetLabelRelativeAddress(string label);
 

GUI.NET/Controls/BaseControl.cs

@@ -22,15 +22,16 @@ namespace Mesen.GUI.Controls
 			}
 		}
 
+		private static bool? _isDesignMode = null;
 		public bool IsDesignMode
 		{
 			get
 			{
 				try {
-					return (
+					if(!_isDesignMode.HasValue) {
-						LicenseManager.UsageMode == LicenseUsageMode.Designtime ||
+						_isDesignMode = System.Diagnostics.Process.GetCurrentProcess().ProcessName == "devenv";
-						System.Diagnostics.Process.GetCurrentProcess().ProcessName == "devenv"
+					}
-					);
+					return _isDesignMode.Value || LicenseManager.UsageMode == LicenseUsageMode.Designtime;
 				} catch {
 					return false;
 				}

GUI.NET/Debugger/Controls/ctrlFunctionList.Designer.cs

@@ -61,6 +61,8 @@
 			this.lstFunctions.TabIndex = 2;
 			this.lstFunctions.UseCompatibleStateImageBehavior = false;
 			this.lstFunctions.View = System.Windows.Forms.View.Details;
+			this.lstFunctions.RetrieveVirtualItem += new System.Windows.Forms.RetrieveVirtualItemEventHandler(this.lstFunctions_RetrieveVirtualItem);
+			this.lstFunctions.SearchForVirtualItem += new System.Windows.Forms.SearchForVirtualItemEventHandler(this.lstFunctions_SearchForVirtualItem);
 			this.lstFunctions.SelectedIndexChanged += new System.EventHandler(this.lstFunctions_SelectedIndexChanged);
 			this.lstFunctions.DoubleClick += new System.EventHandler(this.lstFunctions_DoubleClick);
 			// 

GUI.NET/Debugger/Controls/ctrlFunctionList.cs

@@ -18,6 +18,9 @@ namespace Mesen.GUI.Debugger.Controls
 		public event EventHandler OnFindOccurrence;
 		public event EventHandler OnFunctionSelected;
 
+		private List<ListViewItem> _listItems = new List<ListViewItem>();
+		private Dictionary<Int32, ListViewItem> _functions = new Dictionary<int, ListViewItem>();
+
 		public ctrlFunctionList()
 		{
 			InitializeComponent();
@@ -38,13 +41,8 @@ namespace Mesen.GUI.Debugger.Controls
 			mnuFindOccurrences.InitShortcut(this, nameof(DebuggerShortcutsConfig.FunctionList_FindOccurrences));
 		}
 
-		private class FunctionComparer : IComparer
+		private int CompareFunctions(ListViewItem a, ListViewItem b)
 		{
-			int IComparer.Compare(object x, object y)
-			{
-				ListViewItem a = x as ListViewItem;
-				ListViewItem b = y as ListViewItem;
-
 			string aText = string.IsNullOrWhiteSpace(a.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : a.Text;
 			string bText = string.IsNullOrWhiteSpace(b.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : b.Text;
 			Int32 aRelative = (Int32)a.SubItems[1].Tag == -1 ? Int32.MaxValue : (Int32)a.SubItems[1].Tag;
@@ -62,76 +60,80 @@ namespace Mesen.GUI.Debugger.Controls
 				return string.Compare(aText, bText);
 			}
 		}
-		}
 
-		private Dictionary<Int32, ListViewItem> _functions = new Dictionary<int, ListViewItem>(); 
 		public void UpdateFunctionList(bool reset)
 		{
 			if(reset) {
-				lstFunctions.Items.Clear();
+				_listItems.Clear();
 				_functions.Clear();
 			}
 
+			Font italicFont = null;
+			Font regularFont = null;
+
 			Int32[] entryPoints = InteropEmu.DebugGetFunctionEntryPoints();
-			bool updating = false;
 
 			for(int i = 0; i < entryPoints.Length && entryPoints[i] >= 0; i++) {
 				Int32 entryPoint = entryPoints[i];
 				ListViewItem item;
 				if(!_functions.TryGetValue(entryPoint, out item)) {
-					if(!updating) {
-						updating = true;
-						lstFunctions.BeginUpdate();
-						lstFunctions.ListViewItemSorter = null;
-					}
-
 					CodeLabel label = LabelManager.GetLabel((UInt32)entryPoint, AddressType.PrgRom);
-					item = lstFunctions.Items.Add(label?.Label);
+					item = new ListViewItem(label?.Label);
 					item.Tag = label;
 
 					item.SubItems.Add("[n/a]");
 					item.SubItems[1].Tag = -1;
 					item.ForeColor = Color.Gray;
-					item.Font = new Font(item.Font, FontStyle.Italic);
+
+					if(italicFont == null) {
+						italicFont = new Font(item.Font, FontStyle.Italic);
+					}
+					item.Font = italicFont;
 
 					item.SubItems.Add("$" + entryPoint.ToString("X4"));
 					item.SubItems[2].Tag = entryPoint;
 
+					_listItems.Add(item);
 					_functions[entryPoint] = item;
 				}
 
 				Int32 relativeAddress = InteropEmu.DebugGetRelativeAddress((UInt32)entryPoint, AddressType.PrgRom);
 				if(relativeAddress != (Int32)item.SubItems[1].Tag) {
-					if(!updating) {
-						updating = true;
-						lstFunctions.BeginUpdate();
-						lstFunctions.ListViewItemSorter = null;
-					}
-
 					if(relativeAddress >= 0) {
 						item.SubItems[1].Text = "$" + relativeAddress.ToString("X4");
 						item.ForeColor = Color.Black;
-						item.Font = new Font(item.Font, FontStyle.Regular);
+						if(regularFont == null) {
+							regularFont = new Font(item.Font, FontStyle.Regular);
+						}
+						item.Font = regularFont;
 					} else {
 						item.SubItems[1].Text = "[n/a]";
 						item.ForeColor = Color.Gray;
-						item.Font = new Font(item.Font, FontStyle.Italic);
+						if(italicFont == null) {
+							italicFont = new Font(item.Font, FontStyle.Italic);
+						}
+						item.Font = italicFont;
 					}
 					item.SubItems[1].Tag = relativeAddress;
 				}
 			}
 
-			if(updating) {
+			lstFunctions.BeginUpdate();
-				lstFunctions.ListViewItemSorter = new FunctionComparer();
+			_listItems.Sort(CompareFunctions);
-				lstFunctions.Sort();
+			lstFunctions.VirtualMode = true;
+			lstFunctions.VirtualListSize = _listItems.Count;
 			lstFunctions.EndUpdate();
 		}
+
+		private ListViewItem GetSelectedItem()
+		{
+			return _listItems[lstFunctions.SelectedIndices[0]];
 		}
 
 		private void lstFunctions_DoubleClick(object sender, EventArgs e)
 		{
-			if(lstFunctions.SelectedItems.Count > 0) {
+			if(lstFunctions.SelectedIndices.Count > 0) {
-				Int32 relativeAddress = (Int32)lstFunctions.SelectedItems[0].SubItems[1].Tag;
+				Int32 relativeAddress = (Int32)GetSelectedItem().SubItems[1].Tag;
 
 				if(relativeAddress >= 0) {
 					OnFunctionSelected?.Invoke(relativeAddress, e);
@@ -141,26 +143,26 @@ namespace Mesen.GUI.Debugger.Controls
 
 		private void mnuEditLabel_Click(object sender, EventArgs e)
 		{
-			if(lstFunctions.SelectedItems.Count > 0) {
+			if(lstFunctions.SelectedIndices.Count > 0) {
-				CodeLabel label = lstFunctions.SelectedItems[0].Tag as CodeLabel;
+				CodeLabel label = GetSelectedItem().Tag as CodeLabel;
 				if(label != null) {
 					ctrlLabelList.EditLabel(label.Address, label.AddressType);
 				} else {
-					ctrlLabelList.EditLabel((UInt32)(Int32)lstFunctions.SelectedItems[0].SubItems[2].Tag, AddressType.PrgRom);
+					ctrlLabelList.EditLabel((UInt32)(Int32)GetSelectedItem().SubItems[2].Tag, AddressType.PrgRom);
 				}
 			}
 		}
 
 		private void mnuFindOccurrences_Click(object sender, EventArgs e)
 		{
-			if(lstFunctions.SelectedItems.Count > 0) {
+			if(lstFunctions.SelectedIndices.Count > 0) {
-				int relativeAddress = (int)lstFunctions.SelectedItems[0].SubItems[1].Tag;
+				int relativeAddress = (int)GetSelectedItem().SubItems[1].Tag;
 				if(relativeAddress >= 0) {
-					CodeLabel label = lstFunctions.SelectedItems[0].Tag as CodeLabel;
+					CodeLabel label = GetSelectedItem().Tag as CodeLabel;
 					if(label != null) {
 						OnFindOccurrence?.Invoke(label.Label, null);
 					} else {
-						OnFindOccurrence?.Invoke("$" + ((int)lstFunctions.SelectedItems[0].SubItems[1].Tag).ToString("X4"), null);
+						OnFindOccurrence?.Invoke("$" + ((int)GetSelectedItem().SubItems[1].Tag).ToString("X4"), null);
 					}
 				}
 			}
@@ -168,10 +170,10 @@ namespace Mesen.GUI.Debugger.Controls
 		
 		private void lstFunctions_SelectedIndexChanged(object sender, EventArgs e)
 		{
-			mnuEditLabel.Enabled = lstFunctions.SelectedItems.Count == 1;
+			mnuEditLabel.Enabled = lstFunctions.SelectedIndices.Count == 1;
-			mnuFindOccurrences.Enabled = lstFunctions.SelectedItems.Count == 1;
+			mnuFindOccurrences.Enabled = lstFunctions.SelectedIndices.Count == 1;
-			if(lstFunctions.SelectedItems.Count == 1) {
+			if(lstFunctions.SelectedIndices.Count == 1) {
-				int relativeAddress = (int)lstFunctions.SelectedItems[0].SubItems[1].Tag;
+				int relativeAddress = (int)GetSelectedItem().SubItems[1].Tag;
 				if(relativeAddress < 0) {
 					mnuFindOccurrences.Enabled = false;
 				}
@@ -180,9 +182,9 @@ namespace Mesen.GUI.Debugger.Controls
 
 		private void mnuAddBreakpoint_Click(object sender, EventArgs e)
 		{
-			if(lstFunctions.SelectedItems.Count > 0) {
+			if(lstFunctions.SelectedIndices.Count > 0) {
-				CodeLabel label = lstFunctions.SelectedItems[0].Tag as CodeLabel;
+				CodeLabel label = GetSelectedItem().Tag as CodeLabel;
-				int absoluteAddress = (int)lstFunctions.SelectedItems[0].SubItems[2].Tag;
+				int absoluteAddress = (int)GetSelectedItem().SubItems[2].Tag;
 				BreakpointManager.AddBreakpoint(new Breakpoint() {
 					MemoryType = DebugMemoryType.PrgRom,
 					BreakOnExec = true,
@@ -195,5 +197,15 @@ namespace Mesen.GUI.Debugger.Controls
 				});
 			}
 		}
+
+		private void lstFunctions_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
+		{
+			e.Item = _listItems[e.ItemIndex];
+		}
+
+		private void lstFunctions_SearchForVirtualItem(object sender, SearchForVirtualItemEventArgs e)
+		{
+
+		}
 	}
 }

GUI.NET/Debugger/Controls/ctrlLabelList.Designer.cs

@@ -147,6 +147,8 @@
 			this.lstLabels.UseCompatibleStateImageBehavior = false;
 			this.lstLabels.View = System.Windows.Forms.View.Details;
 			this.lstLabels.ColumnClick += new System.Windows.Forms.ColumnClickEventHandler(this.lstLabels_ColumnClick);
+			this.lstLabels.RetrieveVirtualItem += new System.Windows.Forms.RetrieveVirtualItemEventHandler(this.lstLabels_RetrieveVirtualItem);
+			this.lstLabels.SearchForVirtualItem += new System.Windows.Forms.SearchForVirtualItemEventHandler(this.lstLabels_SearchForVirtualItem);
 			this.lstLabels.SelectedIndexChanged += new System.EventHandler(this.lstLabels_SelectedIndexChanged);
 			this.lstLabels.DoubleClick += new System.EventHandler(this.lstLabels_DoubleClick);
 			// 

GUI.NET/Debugger/Controls/ctrlLabelList.cs

@@ -17,33 +17,14 @@ namespace Mesen.GUI.Debugger.Controls
 	{
 		public event EventHandler OnFindOccurrence;
 		public event EventHandler OnLabelSelected;
+
 		private List<ListViewItem> _listItems = new List<ListViewItem>();
-
+		private int _sortColumn = 0;
-		private class LabelComparer : IComparer
+		private bool _descSort = false;
-		{
-			private int _columnIndex;
-			private bool _sortOrder;
-			public LabelComparer(int columnIndex, bool sortOrder)
-			{
-				_columnIndex = columnIndex;
-				_sortOrder = sortOrder;
-			}
-
-			public int Compare(object x, object y)
-			{
-				int result = String.Compare(((ListViewItem)x).SubItems[_columnIndex].Text, ((ListViewItem)y).SubItems[_columnIndex].Text);
-				if(result == 0 && (_columnIndex == 0 || _columnIndex == 3)) {
-					result = String.Compare(((ListViewItem)x).SubItems[2].Text, ((ListViewItem)y).SubItems[2].Text);
-				}
-
-				return result * (_sortOrder ? -1 : 1);
-			}
-		}
 
 		public ctrlLabelList()
 		{
 			InitializeComponent();
-			lstLabels.ListViewItemSorter = new LabelComparer(0, false);
 		}
 
 		protected override void OnLoad(EventArgs e)
@@ -83,33 +64,52 @@ namespace Mesen.GUI.Debugger.Controls
 			}
 		}
 
+		public int CompareLabels(ListViewItem x, ListViewItem y)
+		{
+			int result = String.Compare(((ListViewItem)x).SubItems[_sortColumn].Text, ((ListViewItem)y).SubItems[_sortColumn].Text);
+			if(result == 0 && (_sortColumn == 0 || _sortColumn == 3)) {
+				result = String.Compare(((ListViewItem)x).SubItems[2].Text, ((ListViewItem)y).SubItems[2].Text);
+			}
+			return result * (_descSort ? -1 : 1);
+		}
+
+		private void SortItems()
+		{
+			_listItems.Sort(CompareLabels);
+		}
+
 		public void UpdateLabelListAddresses()
 		{
-			bool updating = false;
+			bool needUpdate = false;
+			Font italicFont = null;
+			Font regularFont = null;
+
 			foreach(ListViewItem item in _listItems) {
 				CodeLabel label = (CodeLabel)item.SubItems[1].Tag;
 
 				Int32 relativeAddress = InteropEmu.DebugGetRelativeAddress(label.Address, label.AddressType);
 				if(relativeAddress != (Int32)item.Tag) {
-					if(!updating) {
+					needUpdate = true;
-						lstLabels.BeginUpdate();
-						updating = true;
-					}
 					if(relativeAddress >= 0) {
 						item.SubItems[1].Text = "$" + relativeAddress.ToString("X4");
 						item.ForeColor = Color.Black;
-						item.Font = new Font(item.Font, FontStyle.Regular);
+						if(regularFont == null) {
+							regularFont = new Font(item.Font, FontStyle.Regular);
+						}
+						item.Font = regularFont;
 					} else {
 						item.SubItems[1].Text = "[n/a]";
 						item.ForeColor = Color.Gray;
-						item.Font = new Font(item.Font, FontStyle.Italic);
+						if(italicFont == null) {
+							italicFont = new Font(item.Font, FontStyle.Italic);
+						}
+						item.Font = italicFont;
 					}
 					item.Tag = relativeAddress;
 				}
 			}
-			if(updating) {
+			if(needUpdate) {
-				lstLabels.Sort();
+				SortItems();
-				lstLabels.EndUpdate();
 			}
 		}
 
@@ -117,6 +117,7 @@ namespace Mesen.GUI.Debugger.Controls
 		{
 			List<CodeLabel> labels = LabelManager.GetLabels();
 			List<ListViewItem> items = new List<ListViewItem>(labels.Count);
+			Font italicFont = null;
 			foreach(CodeLabel label in labels) {
 				if(label.Label.Length > 0 || ConfigManager.Config.DebugInfo.ShowCommentsInLabelList) {
 					ListViewItem item = new ListViewItem(label.Label);
@@ -127,18 +128,20 @@ namespace Mesen.GUI.Debugger.Controls
 					} else {
 						item.SubItems.Add("[n/a]");
 						item.ForeColor = Color.Gray;
-						item.Font = new Font(item.Font, FontStyle.Italic);
+						if(italicFont == null) {
+							italicFont = new Font(item.Font, FontStyle.Italic);
 						}
-					string absAddress = string.Empty;
+						item.Font = italicFont;
+					}
+					string prefix = string.Empty;
 					switch(label.AddressType) {
-						case AddressType.InternalRam: absAddress += "RAM: "; break;
+						case AddressType.InternalRam: prefix = "RAM: $"; break;
-						case AddressType.PrgRom: absAddress += "PRG: "; break;
+						case AddressType.PrgRom: prefix = "PRG: $"; break;
-						case AddressType.Register: absAddress += "REG: "; break;
+						case AddressType.Register: prefix = "REG: $"; break;
-						case AddressType.SaveRam: absAddress += "SRAM: "; break;
+						case AddressType.SaveRam: prefix = "SRAM: $"; break;
-						case AddressType.WorkRam: absAddress += "WRAM: "; break;
+						case AddressType.WorkRam: prefix = "WRAM: $"; break;
 					}
-					absAddress += "$" + label.Address.ToString("X4");
+					item.SubItems.Add(prefix + label.Address.ToString("X4"));
-					item.SubItems.Add(absAddress);
 					item.SubItems.Add(ConfigManager.Config.DebugInfo.ShowCommentsInLabelList ? label.Comment : "");
 					item.SubItems[1].Tag = label;
 
@@ -147,25 +150,29 @@ namespace Mesen.GUI.Debugger.Controls
 				}
 			}
 
+			_listItems = items;
+			SortItems();
+
 			lstLabels.BeginUpdate();
-			lstLabels.Items.Clear();
+			lstLabels.VirtualMode = true;
-			lstLabels.Items.AddRange(items.ToArray());
+			lstLabels.VirtualListSize = items.Count;
-			lstLabels.Sort();
+			lstLabels.EndUpdate();
 
 			colComment.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent);
 			if(!ConfigManager.Config.DebugInfo.ShowCommentsInLabelList) {
 				colComment.Width = 0;
 			}
+		}
 
-			lstLabels.EndUpdate();
+		private ListViewItem GetSelectedItem()
-
+		{
-			_listItems = items;
+			return _listItems[lstLabels.SelectedIndices[0]];
 		}
 
 		private void lstLabels_DoubleClick(object sender, EventArgs e)
 		{
-			if(lstLabels.SelectedItems.Count > 0) {
+			if(lstLabels.SelectedIndices.Count > 0) {
-				Int32 relativeAddress = (Int32)lstLabels.SelectedItems[0].Tag;
+				Int32 relativeAddress = (Int32)GetSelectedItem().Tag;
 
 				if(relativeAddress >= 0) {
 					OnLabelSelected?.Invoke(relativeAddress, e);
@@ -175,20 +182,20 @@ namespace Mesen.GUI.Debugger.Controls
 		
 		private void lstLabels_SelectedIndexChanged(object sender, EventArgs e)
 		{
-			mnuDelete.Enabled = lstLabels.SelectedItems.Count > 0;
+			mnuDelete.Enabled = lstLabels.SelectedIndices.Count > 0;
-			mnuEdit.Enabled = lstLabels.SelectedItems.Count == 1;
+			mnuEdit.Enabled = lstLabels.SelectedIndices.Count == 1;
-			mnuFindOccurrences.Enabled = lstLabels.SelectedItems.Count == 1;
+			mnuFindOccurrences.Enabled = lstLabels.SelectedIndices.Count == 1;
-			mnuAddToWatch.Enabled = lstLabels.SelectedItems.Count == 1;
+			mnuAddToWatch.Enabled = lstLabels.SelectedIndices.Count == 1;
-			mnuAddBreakpoint.Enabled = lstLabels.SelectedItems.Count == 1;
+			mnuAddBreakpoint.Enabled = lstLabels.SelectedIndices.Count == 1;
 		}
 
 		private void mnuDelete_Click(object sender, EventArgs e)
 		{
-			if(lstLabels.SelectedItems.Count > 0) {
+			if(lstLabels.SelectedIndices.Count > 0) {
 				int topIndex = lstLabels.TopItem.Index;
 				int lastSelectedIndex = lstLabels.SelectedIndices[lstLabels.SelectedIndices.Count - 1];
-				for(int i = lstLabels.SelectedItems.Count - 1; i >= 0; i--) {
+				for(int i = lstLabels.SelectedIndices.Count - 1; i >= 0; i--) {
-					CodeLabel label = (CodeLabel)lstLabels.SelectedItems[i].SubItems[1].Tag;
+					CodeLabel label = (CodeLabel)GetSelectedItem().SubItems[1].Tag;
 					LabelManager.DeleteLabel(label.Address, label.AddressType, i == 0);
 				}
 				
@@ -201,8 +208,8 @@ namespace Mesen.GUI.Debugger.Controls
 				} else if(lstLabels.Items.Count > 0) {
 					lstLabels.Items[lstLabels.Items.Count - 1].Selected = true;
 				}
-				if(lstLabels.SelectedItems.Count > 0) {
+				if(lstLabels.SelectedIndices.Count > 0) {
-					lstLabels.SelectedItems[0].Focused = true;
+					GetSelectedItem().Focused = true;
 				}
 			}
 		}
@@ -219,32 +226,32 @@ namespace Mesen.GUI.Debugger.Controls
 
 		private void mnuEdit_Click(object sender, EventArgs e)
 		{
-			if(lstLabels.SelectedItems.Count > 0) {
+			if(lstLabels.SelectedIndices.Count > 0) {
-				CodeLabel label = (CodeLabel)lstLabels.SelectedItems[0].SubItems[1].Tag;
+				CodeLabel label = (CodeLabel)GetSelectedItem().SubItems[1].Tag;
 				EditLabel(label.Address, label.AddressType);
 			}
 		}
 
 		private void mnuFindOccurrences_Click(object sender, EventArgs e)
 		{
-			OnFindOccurrence?.Invoke(lstLabels.SelectedItems[0].SubItems[1].Tag, null);
+			OnFindOccurrence?.Invoke(GetSelectedItem().SubItems[1].Tag, null);
 		}
 
-		int _prevSortColumn = 0;
-		bool _descSort = false;
 		private void lstLabels_ColumnClick(object sender, ColumnClickEventArgs e)
 		{
-			if(_prevSortColumn == e.Column) {
+			lstLabels.BeginUpdate();
+			if(_sortColumn == e.Column) {
 				_descSort = !_descSort;
 			}
-			lstLabels.ListViewItemSorter = new LabelComparer(e.Column, _descSort);
+			_sortColumn = e.Column;
-			_prevSortColumn = e.Column;
+			SortItems();
+			lstLabels.EndUpdate();
 		}
 
 		private void mnuAddBreakpoint_Click(object sender, EventArgs e)
 		{
-			if(lstLabels.SelectedItems.Count > 0) {
+			if(lstLabels.SelectedIndices.Count > 0) {
-				CodeLabel label = (CodeLabel)lstLabels.SelectedItems[0].SubItems[1].Tag;
+				CodeLabel label = (CodeLabel)GetSelectedItem().SubItems[1].Tag;
 				if(label.AddressType == AddressType.InternalRam || label.AddressType == AddressType.Register) {
 					AddressTypeInfo info = new AddressTypeInfo();
 					InteropEmu.DebugGetAbsoluteAddressAndType(label.Address, ref info);
@@ -277,8 +284,8 @@ namespace Mesen.GUI.Debugger.Controls
 
 		private void mnuAddToWatch_Click(object sender, EventArgs e)
 		{
-			if(lstLabels.SelectedItems.Count > 0) {
+			if(lstLabels.SelectedIndices.Count > 0) {
-				CodeLabel label = (CodeLabel)lstLabels.SelectedItems[0].SubItems[1].Tag;
+				CodeLabel label = (CodeLabel)GetSelectedItem().SubItems[1].Tag;
 				WatchManager.AddWatch("[" + label.Label + "]");
 			}			
 		}
@@ -289,5 +296,20 @@ namespace Mesen.GUI.Debugger.Controls
 			ConfigManager.ApplyChanges();
 			this.UpdateLabelList();
 		}
+
+		private void lstLabels_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
+		{
+			e.Item = _listItems[e.ItemIndex];
+		}
+
+		private void lstLabels_SearchForVirtualItem(object sender, SearchForVirtualItemEventArgs e)
+		{
+			for(int i = 0; i < _listItems.Count; i++) {
+				if(_listItems[i].Text.StartsWith(e.Text, StringComparison.InvariantCultureIgnoreCase)) {
+					e.Index = i;
+					return;
+				}
+			}
+		}
 	}
 }

GUI.NET/Debugger/DbgImporter.cs

@@ -499,14 +499,16 @@ namespace Mesen.GUI.Debugger
 			if(config.DbgImportComments) {
 				LoadComments();
 			}
+			List<CodeLabel> labels = new List<CodeLabel>(_romLabels.Count + _ramLabels.Count);
 			if(config.DbgImportPrgRomLabels) {
-				LabelManager.SetLabels(_romLabels.Values);
+				labels.AddRange(_romLabels.Values);
 				labelCount += _romLabels.Count;
 			}
 			if(config.DbgImportRamLabels) {
-				LabelManager.SetLabels(_ramLabels.Values);
+				labels.AddRange(_ramLabels.Values);
 				labelCount += _ramLabels.Count;
 			}
+			LabelManager.SetLabels(labels);
 			
 			if(!silent) {
 				if(_errorCount > 0) {

GUI.NET/Debugger/LabelManager.cs

@@ -50,16 +50,16 @@ namespace Mesen.GUI.Debugger
 
 		public static void ResetLabels()
 		{
-			foreach(CodeLabel label in _labels.Values.ToList<CodeLabel>()) {
+			InteropEmu.DebugDeleteLabels();
-				DeleteLabel(label.Address, label.AddressType, false);
-			}
 			_labels.Clear();
 			_reverseLookup.Clear();
 		}
 
 		public static CodeLabel GetLabel(UInt32 address, AddressType type)
 		{
-			return _labels.ContainsKey(GetKey(address, type)) ? _labels[GetKey(address, type)] : null;
+			CodeLabel label;
+			_labels.TryGetValue(GetKey(address, type), out label);
+			return label;
 		}
 
 		public static CodeLabel GetLabel(UInt16 relativeAddress)
@@ -99,13 +99,14 @@ namespace Mesen.GUI.Debugger
 
 		public static bool SetLabel(UInt32 address, AddressType type, string label, string comment, bool raiseEvent = true)
 		{
-			if(_labels.ContainsKey(GetKey(address, type))) {
+			string key = GetKey(address, type);
-				_reverseLookup.Remove(_labels[GetKey(address, type)].Label);
+			if(_labels.ContainsKey(key)) {
+				_reverseLookup.Remove(_labels[key].Label);
 			}
 
-			_labels[GetKey(address, type)] = new CodeLabel() { Address = address, AddressType = type, Label = label, Comment = comment };
+			_labels[key] = new CodeLabel() { Address = address, AddressType = type, Label = label, Comment = comment };
 			if(label.Length > 0) {
-				_reverseLookup[label] = _labels[GetKey(address, type)];
+				_reverseLookup[label] = _labels[key];
 			}
 
 			InteropEmu.DebugSetLabel(address, type, label, comment.Replace(Environment.NewLine, "\n"));
@@ -118,10 +119,11 @@ namespace Mesen.GUI.Debugger
 
 		public static void DeleteLabel(UInt32 address, AddressType type, bool raiseEvent)
 		{
-			if(_labels.ContainsKey(GetKey(address, type))) {
+			string key = GetKey(address, type);
-				_reverseLookup.Remove(_labels[GetKey(address, type)].Label);
+			if(_labels.ContainsKey(key)) {
+				_reverseLookup.Remove(_labels[key].Label);
 			}
-			if(_labels.Remove(GetKey(address, type))) {
+			if(_labels.Remove(key)) {
 				InteropEmu.DebugSetLabel(address, type, string.Empty, string.Empty);
 				if(raiseEvent) {
 					OnLabelUpdated?.Invoke(null, null);

GUI.NET/Debugger/MesenLabelFile.cs

@@ -63,9 +63,13 @@ namespace Mesen.GUI.Debugger
 
 			int labelCount = 0;
 			foreach(KeyValuePair<AddressType, Dictionary<UInt32, CodeLabel>> kvp in labels) {
-				LabelManager.SetLabels(kvp.Value.Values);
 				labelCount += kvp.Value.Values.Count;
 			}
+			List<CodeLabel> codeLabels = new List<CodeLabel>();
+			foreach(KeyValuePair<AddressType, Dictionary<UInt32, CodeLabel>> kvp in labels) {
+				codeLabels.AddRange(kvp.Value.Values);
+			}
+			LabelManager.SetLabels(codeLabels);
 
 			if(!silent) {
 				MessageBox.Show($"Import completed with {labelCount} labels imported.", "Mesen", MessageBoxButtons.OK, MessageBoxIcon.Information);

GUI.NET/InteropEmu.cs

@@ -209,6 +209,7 @@ namespace Mesen.GUI
 		[DllImport(DLLPath)] public static extern void DebugSetState(DebugState state);
 		[DllImport(DLLPath)] public static extern void DebugSetBreakpoints([MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)]InteropBreakpoint[] breakpoints, UInt32 length);
 		[DllImport(DLLPath)] public static extern void DebugSetLabel(UInt32 address, AddressType addressType, [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(UTF8Marshaler))]string label, [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(UTF8Marshaler))]string comment);
+		[DllImport(DLLPath)] public static extern void DebugDeleteLabels();
 		[DllImport(DLLPath)] public static extern void DebugStep(UInt32 count);
 		[DllImport(DLLPath)] public static extern void DebugPpuStep(UInt32 count);
 		[DllImport(DLLPath)] public static extern void DebugStepCycles(UInt32 count);

InteropDLL/DebugWrapper.cpp

@@ -39,6 +39,7 @@ extern "C"
 
 	DllExport void __stdcall DebugSetBreakpoints(Breakpoint breakpoints[], uint32_t length) { GetDebugger()->SetBreakpoints(breakpoints, length); }
 	DllExport void __stdcall DebugSetLabel(uint32_t address, AddressType addressType, char* label, char* comment) { GetDebugger()->GetLabelManager()->SetLabel(address, addressType, label, comment); }
+	DllExport void __stdcall DebugDeleteLabels() { GetDebugger()->GetLabelManager()->DeleteLabels(); }
 
 	DllExport bool __stdcall DebugIsExecutionStopped() { return GetDebugger()->IsExecutionStopped(); }
 	DllExport void __stdcall DebugRun() { GetDebugger()->Run(); }