Add ETW for event + property decompilation as PoC

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -1744,6 +1744,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		EntityDeclaration DoDecompile(IProperty property, DecompileRun decompileRun, ITypeResolveContext decompilationContext)
 		{
 			Debug.Assert(decompilationContext.CurrentMember == property);
+			var watch = System.Diagnostics.Stopwatch.StartNew();
 			try
 			{
 				var typeSystemAstBuilder = CreateAstBuilder(decompileRun.Settings);
@@ -1798,11 +1799,17 @@ namespace ICSharpCode.Decompiler.CSharp
 			{
 				throw new DecompilerException(module, property, innerException);
 			}
+			finally
+			{
+				watch.Stop();
+				Instrumentation.DecompilerEventSource.Log.DoDecompileProperty(property.Name, watch.ElapsedMilliseconds);
+			}
 		}
 
 		EntityDeclaration DoDecompile(IEvent ev, DecompileRun decompileRun, ITypeResolveContext decompilationContext)
 		{
 			Debug.Assert(decompilationContext.CurrentMember == ev);
+			var watch = System.Diagnostics.Stopwatch.StartNew();
 			try
 			{
 				var typeSystemAstBuilder = CreateAstBuilder(decompileRun.Settings);
@@ -1838,6 +1845,11 @@ namespace ICSharpCode.Decompiler.CSharp
 			{
 				throw new DecompilerException(module, ev, innerException);
 			}
+			finally
+			{
+				watch.Stop();
+				Instrumentation.DecompilerEventSource.Log.DoDecompileEvent(ev.Name, watch.ElapsedMilliseconds);
+			}
 		}
 
 		#region Sequence Points

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -100,6 +100,7 @@
     <Compile Include="IL\Transforms\LdLocaDupInitObjTransform.cs" />
     <Compile Include="IL\Transforms\PatternMatchingTransform.cs" />
     <Compile Include="IL\Transforms\RemoveInfeasiblePathTransform.cs" />
+    <Compile Include="Instrumentation\DecompilerEventSource.cs" />
     <Compile Include="Metadata\ReferenceLoadInfo.cs" />
     <Compile Include="Semantics\OutVarResolveResult.cs" />
     <Compile Include="SingleFileBundle.cs" />

ICSharpCode.Decompiler/Instrumentation/DecompilerEventSource.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Diagnostics.Tracing;
+
+namespace ICSharpCode.Decompiler.Instrumentation
+{
+	[EventSource(Name = "ICSharpCode.Decompiler")]
+	public sealed class DecompilerEventSource : EventSource
+	{
+		[Event(1, Level = EventLevel.Informational)]
+		public void DoDecompileEvent(string eventName, long elapsedMilliseconds)
+		{
+			WriteEvent(1, eventName, elapsedMilliseconds);
+		}
+
+		[Event(2, Level = EventLevel.Informational)]
+		public void DoDecompileProperty(string propertyName, long elapsedMilliseconds)
+		{
+			WriteEvent(2, propertyName, elapsedMilliseconds);
+		}
+
+		public static DecompilerEventSource Log = new DecompilerEventSource();
+	}
+
+}