Respect EventSource::IsSupported setting in more codepaths

src/libraries/System.Private.CoreLib/generators/EventSourceGenerator.Emitter.cs

@@ -52,6 +52,8 @@ partial class {ec.ClassName}
     {{");
                 GenerateConstructor(ec);
 
+                GenerateLogSingleton(ec.ClassName);
+
                 GenerateProviderMetadata(ec.SourceName);
 
                 _builder.AppendLine($@"
@@ -68,6 +70,15 @@ private void GenerateConstructor(EventSourceClass ec)
             {
                 _builder.AppendLine($@"
         private {ec.ClassName}() : base(new Guid({ec.Guid.ToString("x").Replace("{", "").Replace("}", "")}), ""{ec.SourceName}"") {{ }}");
+
+                _builder.AppendLine($@"
+        private {ec.ClassName}(bool _) : base() {{ }}");
+            }
+
+            private void GenerateLogSingleton(string className)
+            {
+                _builder.AppendLine($@"
+        public static readonly {className} Log = IsSupported ? new() : new(false);");
             }
 
             private void GenerateProviderMetadata(string sourceName)

src/libraries/System.Private.CoreLib/generators/EventSourceGenerator.cs

@@ -28,6 +28,10 @@ public partial class EventSourceGenerator : ISourceGenerator
         //         {
         //             private RuntimeEventSource() : base(new Guid(0x49592c0f,0x5a05,0x516d,0xaa,0x4b,0xa6,0x4e,0x02,0x02,0x6c,0x89), "System.Runtime") { }
         //
+        //             private RuntimeEventSource(bool _) : base() { }
+        //
+        //             public static readonly RuntimeEventSource Log = IsSupported ? new() : new(false);
+        //
         //             private protected override ReadOnlySpan<byte> ProviderMetadata => new byte[] { 0x11, 0x0, 0x53, 0x79, 0x73, 0x74, 0x65, 0x6d, 0x2e, 0x52, 0x75, 0x6e, 0x74, 0x69, 0x6d, 0x65, 0x0, };
         //         }
         //     }

src/libraries/System.Private.CoreLib/src/System/Buffers/ArrayPoolEventSource.cs

@@ -13,8 +13,6 @@ internal sealed partial class ArrayPoolEventSource : EventSource
 #if !ES_BUILD_STANDALONE
         private const string EventSourceSuppressMessage = "Parameters to this method are primitive and are trimmer safe";
 #endif
-        internal static readonly ArrayPoolEventSource Log = new ArrayPoolEventSource();
-
         /// <summary>Bucket ID used when renting/returning an array that's too large for a pool.</summary>
         internal const int NoBucketId = -1;
 
@@ -38,10 +36,6 @@ internal enum BufferDroppedReason : int
             OverMaximumSize,
         }
 
-        // Parameterized constructor to block initialization and ensure the EventSourceGenerator is creating the default constructor
-        // as you can't make a constructor partial.
-        private ArrayPoolEventSource(int _) { }
-
         /// <summary>
         /// Event for when a buffer is rented.  This is invoked once for every successful call to Rent,
         /// regardless of whether a buffer is allocated or a buffer is taken from the pool.  In a

src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/EventSource.cs

@@ -493,6 +493,9 @@ public static void SendCommand(EventSource eventSource, EventCommand command, ID
         /// </summary>
         public override string ToString()
         {
+            if (!IsSupported)
+                return string.Empty;
+
             return SR.Format(SR.EventSource_ToString, Name, Guid);
         }
 
@@ -666,8 +669,15 @@ public static void SetCurrentThreadActivityId(Guid activityId, out Guid oldActiv
         /// the ETW provider name.
         /// </summary>
         protected EventSource()
-            : this(EventSourceSettings.EtwManifestEventFormat)
         {
+            if (!IsSupported)
+                return;
+
+#if FEATURE_PERFTRACING
+            m_eventHandleTable = new TraceLoggingEventHandleTable();
+#endif
+            m_config = EventSourceSettings.EtwManifestEventFormat;
+            Initialize(null);
         }
 
         /// <summary>
@@ -701,19 +711,23 @@ protected EventSource(EventSourceSettings settings) : this(settings, null) { }
         /// <param name="traits">A collection of key-value strings (must be an even number).</param>
         protected EventSource(EventSourceSettings settings, params string[]? traits)
         {
-            if (IsSupported)
-            {
+            if (!IsSupported)
+                return;
+
 #if FEATURE_PERFTRACING
-                m_eventHandleTable = new TraceLoggingEventHandleTable();
+            m_eventHandleTable = new TraceLoggingEventHandleTable();
 #endif
-                m_config = ValidateSettings(settings);
+            m_config = ValidateSettings(settings);
+            Initialize(traits);
+        }
 
-                Type myType = this.GetType();
-                Guid eventSourceGuid = GetGuid(myType);
-                string eventSourceName = GetName(myType);
+        private void Initialize(string[]? traits)
+        {
+            Type myType = this.GetType();
+            Guid eventSourceGuid = GetGuid(myType);
+            string eventSourceName = GetName(myType);
 
-                Initialize(eventSourceGuid, eventSourceName, traits);
-            }
+            Initialize(eventSourceGuid, eventSourceName, traits);
         }
 
 #if FEATURE_PERFTRACING
@@ -1546,6 +1560,8 @@ internal EventSource(Guid eventSourceGuid, string eventSourceName, EventSourceSe
         /// </summary>
         private unsafe void Initialize(Guid eventSourceGuid, string eventSourceName, string[]? traits)
         {
+            Debug.Assert(IsSupported);
+
             try
             {
                 m_traits = traits;

src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/FrameworkEventSource.cs

@@ -14,7 +14,6 @@ internal sealed partial class FrameworkEventSource : EventSource
 #if !ES_BUILD_STANDALONE
         private const string EventSourceSuppressMessage = "Parameters to this method are primitive and are trimmer safe";
 #endif
-        public static readonly FrameworkEventSource Log = new FrameworkEventSource();
 
         // Keyword definitions.  These represent logical groups of events that can be turned on and off independently
         // Often each task has a keyword, but where tasks are determined by subsystem, keywords are determined by
@@ -33,10 +32,6 @@ public static class Keywords
             public const EventTask ThreadTransfer = (EventTask)3;
         }
 
-        // Parameterized constructor to block initialization and ensure the EventSourceGenerator is creating the default constructor
-        // as you can't make a constructor partial.
-        private FrameworkEventSource(int _) { }
-
         // optimized for common signatures (used by the ThreadTransferSend/Receive events)
 #if !ES_BUILD_STANDALONE
         [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",

src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/NativeRuntimeEventSource.cs

@@ -17,11 +17,6 @@ namespace System.Diagnostics.Tracing
     internal sealed partial class NativeRuntimeEventSource : EventSource
     {
         internal const string EventSourceName = "Microsoft-Windows-DotNETRuntime";
-        public static readonly NativeRuntimeEventSource Log = new NativeRuntimeEventSource();
-
-        // Parameterized constructor to block initialization and ensure the EventSourceGenerator is creating the default constructor
-        // as you can't make a constructor partial.
-        private NativeRuntimeEventSource(int _) { }
 
 #if FEATURE_PERFTRACING
         /// <summary>

src/libraries/System.Private.CoreLib/src/System/Diagnostics/Tracing/RuntimeEventSource.cs

@@ -45,10 +45,6 @@ public static void Initialize()
             s_RuntimeEventSource = new RuntimeEventSource();
         }
 
-        // Parameterized constructor to block initialization and ensure the EventSourceGenerator is creating the default constructor
-        // as you can't make a constructor partial.
-        private RuntimeEventSource(int _) { }
-
         protected override void OnEventCommand(EventCommandEventArgs command)
         {
             if (command.Command == EventCommand.Enable)

src/libraries/System.Private.CoreLib/src/System/Threading/Tasks/TplEventSource.cs

@@ -46,15 +46,6 @@ protected override void OnEventCommand(EventCommandEventArgs command)
             DebugActivityId = IsEnabled(EventLevel.Informational, Keywords.DebugActivityId);
         }
 
-        /// <summary>
-        /// Defines the singleton instance for the TPL ETW provider.
-        /// </summary>
-        public static readonly TplEventSource Log = new TplEventSource();
-
-        // Parameterized constructor to block initialization and ensure the EventSourceGenerator is creating the default constructor
-        // as you can't make a constructor partial.
-        private TplEventSource(int _) { }
-
         /// <summary>Configured behavior of a task wait operation.</summary>
         public enum TaskWaitBehavior : int
         {