More DebugStep UI options

ICSharpCode.Decompiler/IL/Transforms/Stepper.cs

@@ -54,12 +54,20 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		public IList<Node> Steps => steps;
 
 		public int StepLimit { get; set; } = int.MaxValue;
+		public bool IsDebug { get; set; }
 
 		public class Node
 		{
 			public string Description { get; set; }
 			public ILInstruction Position { get; set; }
-			public int Step { get; set; }
+			/// <summary>
+			/// BeginStep is inclusive.
+			/// </summary>
+			public int BeginStep { get; set; }
+			/// <summary>
+			/// EndStep is exclusive.
+			/// </summary>
+			public int EndStep { get; set; }
 
 			public IList<Node> Children { get; } = new List<Node>();
 		}
@@ -87,12 +95,17 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 
 		private Node StepInternal(string description, ILInstruction near)
 		{
-			if (step >= StepLimit)
-				throw new StepLimitReachedException();
+			if (step >= StepLimit) {
+				if (IsDebug)
+					Debugger.Break();
+				else
+					throw new StepLimitReachedException();
+			}
 			var stepNode = new Node {
 				Description = $"{step}: {description}",
 				Position = near,
-				Step = step
+				BeginStep = step,
+				EndStep = step + 1
 			};
 			var p = groups.PeekOrDefault();
 			if (p != null)
@@ -116,6 +129,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				Debug.Assert(col.Last() == node);
 				col.RemoveAt(col.Count - 1);
 			}
+			node.EndStep = step;
 		}
 	}
 }

ILSpy/DebugSteps.xaml

@@ -7,12 +7,19 @@
              mc:Ignorable="d" 
              d:DesignHeight="300" d:DesignWidth="300">
 	<Grid>
-		<TreeView Name="tree" MouseDoubleClick="tree_MouseDoubleClick">
+		<TreeView Name="tree" MouseDoubleClick="ShowStateAfter_Click">
 			<TreeView.ItemTemplate>
 				<HierarchicalDataTemplate ItemsSource="{Binding Children}">
 					<TextBlock Text="{Binding Description}" />
 				</HierarchicalDataTemplate>
 			</TreeView.ItemTemplate>
+			<TreeView.ContextMenu>
+				<ContextMenu>
+					<MenuItem Header="Show state before this step" Click="ShowStateBefore_Click" />
+					<MenuItem Header="Show state after this step" Click="ShowStateAfter_Click" />
+					<MenuItem Header="Debug this step" Click="DebugStep_Click" />
+				</ContextMenu>
+			</TreeView.ContextMenu>
 		</TreeView>
 	</Grid>
 </UserControl>

ILSpy/DebugSteps.xaml.cs

@@ -76,12 +76,31 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		private void tree_MouseDoubleClick(object sender, MouseButtonEventArgs e)
+		private void ShowStateAfter_Click(object sender, RoutedEventArgs e)
 		{
 			Stepper.Node n = (Stepper.Node)tree.SelectedItem;
 			if (n == null) return;
+			DecompileAsync(n.EndStep);
+		}
+
+		private void ShowStateBefore_Click(object sender, RoutedEventArgs e)
+		{
+			Stepper.Node n = (Stepper.Node)tree.SelectedItem;
+			if (n == null) return;
+			DecompileAsync(n.BeginStep);
+		}
+
+		private void DebugStep_Click(object sender, RoutedEventArgs e)
+		{
+			Stepper.Node n = (Stepper.Node)tree.SelectedItem;
+			if (n == null) return;
+			DecompileAsync(n.BeginStep, true);
+		}
+
+		void DecompileAsync(int step, bool isDebug = false)
+		{
 			var window = MainWindow.Instance;
-			window.TextView.DecompileAsync(window.CurrentLanguage, window.SelectedNodes, new DecompilationOptions() { StepLimit = n.Step + 1 });
+			window.TextView.DecompileAsync(window.CurrentLanguage, window.SelectedNodes, new DecompilationOptions() { StepLimit = step, IsDebug = isDebug });
 		}
 	}
 }

ILSpy/DecompilationOptions.cs

@@ -66,6 +66,7 @@ namespace ICSharpCode.ILSpy
 		/// Used internally for debugging.
 		/// </summary>
 		internal int StepLimit = int.MaxValue;
+		internal bool IsDebug = false;
 
 		public DecompilationOptions()
 		{

ILSpy/Languages/ILAstLanguage.cs

@@ -157,6 +157,7 @@ namespace ICSharpCode.ILSpy
 				ILFunction il = reader.ReadIL(method.Body, options.CancellationToken);
 				ILTransformContext context = new ILTransformContext { Settings = options.DecompilerSettings, TypeSystem = typeSystem };
 				context.Stepper.StepLimit = options.StepLimit;
+				context.Stepper.IsDebug = options.IsDebug;
 				try {
 					il.RunTransforms(transforms, context);
 				} catch (StepLimitReachedException) {