Added UI for debug steps

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -44,6 +44,7 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'">
     <Prefer32Bit>false</Prefer32Bit>
+    <DefineConstants>TRACE;DEBUG;STEP</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'">
     <Prefer32Bit>false</Prefer32Bit>

ICSharpCode.Decompiler/IL/Transforms/BlockTransform.cs

@@ -89,6 +89,8 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 
 		void VisitBlock(ControlFlowNode cfgNode, BlockTransformContext context)
 		{
+			Block block = (Block)cfgNode.UserData;
+			context.Stepper.StartGroup(block.Label, block);
 			// First, process the children in the dominator tree.
 			// The ConditionDetection transform requires dominated blocks to
 			// be already processed.
@@ -97,13 +99,14 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			}
 
 			context.ControlFlowNode = cfgNode;
-			context.Block = (Block)cfgNode.UserData;
+			context.Block = block;
 			context.Block.CheckInvariant(ILPhase.Normal);
 			foreach (var transform in blockTransforms) {
 				context.CancellationToken.ThrowIfCancellationRequested();
 				transform.Run(context.Block, context);
 				context.Block.CheckInvariant(ILPhase.Normal);
 			}
+			context.Stepper.EndGroup();
 		}
 	}
 }

ICSharpCode.Decompiler/IL/Transforms/IILTransform.cs

@@ -42,6 +42,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 
 		public ILTransformContext()
 		{
+			Stepper = new Stepper();
 		}
 
 		public ILTransformContext(ILTransformContext context)
@@ -49,6 +50,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			this.TypeSystem = context.TypeSystem;
 			this.Settings = context.Settings;
 			this.CancellationToken = context.CancellationToken;
+			this.Stepper = context.Stepper;
 		}
 
 		/// <summary>

ICSharpCode.Decompiler/IL/Transforms/Stepper.cs

@@ -49,6 +49,29 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 #endif
 			}
 		}
+
+		public IList<Node> Steps => steps;
+
+		public int StepLimit { get; set; } = int.MaxValue;
+
+		public class Node
+		{
+			public string Description { get; set; }
+			public ILInstruction Position { get; set; }
+			public int Step { get; set; }
+
+			public ICollection<Node> Children { get; } = new List<Node>();
+		}
+
+		readonly Stack<Node> groups;
+		readonly IList<Node> steps;
+		int step = 0;
+
+		public Stepper()
+		{
+			steps = new List<Node>();
+			groups = new Stack<Node>();
+		}
 		
 		/// <summary>
 		/// Call this method immediately before performing a transform step.
@@ -58,7 +81,31 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		/// </summary>
 		public void Step(string description, ILInstruction near)
 		{
-			// TODO: implement stepping
+			StepInternal(description, near);
+		}
+
+		private Node StepInternal(string description, ILInstruction near)
+		{
+			if (step >= StepLimit)
+				throw new StepLimitReachedException();
+			var stepNode = new Node { Description = $"{description} ({step})", Position = near, Step = step };
+			var p = groups.PeekOrDefault();
+			if (p != null)
+				p.Children.Add(stepNode);
+			else
+				steps.Add(stepNode);
+			step++;
+			return stepNode;
+		}
+
+		public void StartGroup(string description, ILInstruction near)
+		{
+			groups.Push(StepInternal(description, near));
+		}
+
+		public void EndGroup()
+		{
+			groups.Pop();
 		}
 	}
 }

ILSpy/Commands/ShowDebugSteps.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ICSharpCode.ILSpy.Commands
+{
+	[ExportMainMenuCommand(Menu = "_View", Header = "_Show debug steps", MenuOrder = 5000)]
+	class ShowDebugSteps : SimpleCommand
+	{
+		public override void Execute(object parameter)
+		{
+			DebugSteps.Show();
+		}
+	}
+}

ILSpy/DebugSteps.xaml

@@ -0,0 +1,18 @@
+<UserControl x:Class="ICSharpCode.ILSpy.DebugSteps"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:local="clr-namespace:ICSharpCode.ILSpy"
+             mc:Ignorable="d" 
+             d:DesignHeight="300" d:DesignWidth="300">
+	<Grid>
+		<TreeView Name="tree" MouseDoubleClick="tree_MouseDoubleClick">
+			<TreeView.ItemTemplate>
+				<HierarchicalDataTemplate ItemsSource="{Binding Children}">
+					<TextBlock Text="{Binding Description}" />
+				</HierarchicalDataTemplate>
+			</TreeView.ItemTemplate>
+		</TreeView>
+	</Grid>
+</UserControl>

ILSpy/DebugSteps.xaml.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+using ICSharpCode.Decompiler.IL.Transforms;
+
+namespace ICSharpCode.ILSpy
+{
+	/// <summary>
+	/// Interaktionslogik für DebugSteps.xaml
+	/// </summary>
+	public partial class DebugSteps : UserControl, IPane
+	{
+		ILAstLanguage language;
+
+		DebugSteps()
+		{
+			InitializeComponent();
+
+			MainWindow.Instance.SessionSettings.FilterSettings.PropertyChanged += FilterSettings_PropertyChanged;
+			MainWindow.Instance.SelectionChanged += SelectionChanged;
+
+			if (MainWindow.Instance.CurrentLanguage is ILAstLanguage l) {
+				l.StepperUpdated += ILAstStepperUpdated;
+				language = l;
+				ILAstStepperUpdated(null, null);
+			}
+		}
+
+		private void SelectionChanged(object sender, SelectionChangedEventArgs e)
+		{
+			Dispatcher.Invoke(() => tree.ItemsSource = null);
+		}
+
+		private void FilterSettings_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
+		{
+			if (e.PropertyName == "CurrentLanguage") {
+				if (language != null) {
+					language.StepperUpdated -= ILAstStepperUpdated;
+				}
+				if (MainWindow.Instance.CurrentLanguage is ILAstLanguage l) {
+					l.StepperUpdated += ILAstStepperUpdated;
+					language = l;
+					ILAstStepperUpdated(null, null);
+				}
+			}
+		}
+
+		private void ILAstStepperUpdated(object sender, EventArgs e)
+		{
+			if (language == null) return;
+			Dispatcher.Invoke(() => tree.ItemsSource = language.Stepper.Steps);
+		}
+
+		public static void Show()
+		{
+			MainWindow.Instance.ShowInTopPane("Debug Steps", new DebugSteps());
+		}
+
+		void IPane.Closed()
+		{
+			MainWindow.Instance.SessionSettings.FilterSettings.PropertyChanged -= FilterSettings_PropertyChanged;
+			MainWindow.Instance.SelectionChanged -= SelectionChanged;
+			if (language != null) {
+				language.StepperUpdated -= ILAstStepperUpdated;
+			}
+		}
+
+		private void tree_MouseDoubleClick(object sender, MouseButtonEventArgs e)
+		{
+			Stepper.Node n = (Stepper.Node)tree.SelectedItem;
+			var window = MainWindow.Instance;
+			window.TextView.DecompileAsync(window.CurrentLanguage, window.SelectedNodes, new DecompilationOptions() { StepLimit = n.Step + 1 });
+		}
+	}
+}

ILSpy/DecompilationOptions.cs

@@ -62,6 +62,11 @@ namespace ICSharpCode.ILSpy
 		/// </remarks>
 		public TextView.DecompilerTextViewState TextViewState { get; set; }
 
+		/// <summary>
+		/// Used internally for debugging.
+		/// </summary>
+		internal int StepLimit = int.MaxValue;
+
 		public DecompilationOptions()
 		{
 			this.DecompilerSettings = DecompilerSettingsPanel.CurrentDecompilerSettings;

ILSpy/ILSpy.csproj

@@ -130,6 +130,7 @@
     <Compile Include="Commands\ExitCommand.cs" />
     <Compile Include="Commands\CommandWrapper.cs" />
     <Compile Include="Commands\OpenListCommand.cs" />
+    <Compile Include="Commands\ShowDebugSteps.cs" />
     <Compile Include="Commands\SortAssemblyListCommand.cs" />
     <Compile Include="Controls\CustomDialog.cs">
       <SubType>Form</SubType>
@@ -147,6 +148,9 @@
     <Compile Include="CreateListDialog.xaml.cs">
       <DependentUpon>CreateListDialog.xaml</DependentUpon>
     </Compile>
+    <Compile Include="DebugSteps.xaml.cs">
+      <DependentUpon>DebugSteps.xaml</DependentUpon>
+    </Compile>
     <Compile Include="ILSpyTraceListener.cs" />
     <Compile Include="Languages\CSharpLanguage.cs" />
     <Compile Include="DecompilationOptions.cs" />
@@ -333,6 +337,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="DebugSteps.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="MainWindow.xaml" />
     <Page Include="OpenFromGacDialog.xaml" />
     <Page Include="OpenListDialog.xaml" />

ILSpy/Languages/ILAstLanguage.cs

@@ -36,7 +36,14 @@ namespace ICSharpCode.ILSpy
 	/// </summary>
 	abstract class ILAstLanguage : Language
 	{
-		//ILAstOptimizationStep? abortBeforeStep;
+		public event EventHandler StepperUpdated;
+
+		protected virtual void OnStepperUpdated(EventArgs e = null)
+		{
+			StepperUpdated?.Invoke(this, e ?? new EventArgs());
+		}
+
+		public Stepper Stepper { get; set; } = new Stepper();
 
 		readonly string name;
 		
@@ -161,8 +168,17 @@ namespace ICSharpCode.ILSpy
 				var typeSystem = new DecompilerTypeSystem(method.Module);
 				ILReader reader = new ILReader(typeSystem);
 				ILFunction il = reader.ReadIL(method.Body, options.CancellationToken);
-				il.RunTransforms(transforms, new ILTransformContext { Settings = options.DecompilerSettings, TypeSystem = typeSystem });
+				ILTransformContext context = new ILTransformContext { Settings = options.DecompilerSettings, TypeSystem = typeSystem };
+				context.Stepper.StepLimit = options.StepLimit;
+				try {
+					il.RunTransforms(transforms, context);
+				} catch (StepLimitReachedException) {
+					il.WriteTo(output);
+					return;
+				}
+				Stepper = context.Stepper;
 				il.WriteTo(output);
+				OnStepperUpdated(new EventArgs());
 			}
 		}
 	}