[AOT] suppressed trimming warnings in HTTP Instrumentation package

build/test-aot-compatibility.ps1

@@ -29,7 +29,7 @@ if ($LastExitCode -ne 0)
 popd
 
 Write-Host "Actual warning count is:", $actualWarningCount
-$expectedWarningCount = 26
+$expectedWarningCount = 20
 
 $testPassed = 0
 if ($actualWarningCount -ne $expectedWarningCount)

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs

@@ -15,6 +15,9 @@
 // </copyright>
 
 using System.Diagnostics;
+#if NET6_0_OR_GREATER
+using System.Diagnostics.CodeAnalysis;
+#endif
 #if NETFRAMEWORK
 using System.Net.Http;
 #endif
@@ -40,10 +43,10 @@ internal sealed class HttpHandlerDiagnosticListener : ListenerHandler
     private const string OnStopEvent = "System.Net.Http.HttpRequestOut.Stop";
     private const string OnUnhandledExceptionEvent = "System.Net.Http.Exception";
 
-    private readonly PropertyFetcher<HttpRequestMessage> startRequestFetcher = new("Request");
-    private readonly PropertyFetcher<HttpResponseMessage> stopResponseFetcher = new("Response");
-    private readonly PropertyFetcher<Exception> stopExceptionFetcher = new("Exception");
-    private readonly PropertyFetcher<TaskStatus> stopRequestStatusFetcher = new("RequestTaskStatus");
+    private static readonly PropertyFetcher<HttpRequestMessage> StartRequestFetcher = new("Request");
+    private static readonly PropertyFetcher<HttpResponseMessage> StopResponseFetcher = new("Response");
+    private static readonly PropertyFetcher<Exception> StopExceptionFetcher = new("Exception");
+    private static readonly PropertyFetcher<TaskStatus> StopRequestStatusFetcher = new("RequestTaskStatus");
     private readonly HttpClientInstrumentationOptions options;
     private readonly bool emitOldAttributes;
     private readonly bool emitNewAttributes;
@@ -112,7 +115,7 @@ public void OnStartActivity(Activity activity, object payload)
             return;
         }
 
-        if (!this.startRequestFetcher.TryFetch(payload, out HttpRequestMessage request) || request == null)
+        if (!TryFetchRequest(payload, out HttpRequestMessage request))
         {
             HttpInstrumentationEventSource.Log.NullPayload(nameof(HttpHandlerDiagnosticListener), nameof(this.OnStartActivity));
             return;
@@ -211,15 +214,28 @@ public void OnStartActivity(Activity activity, object payload)
                 HttpInstrumentationEventSource.Log.EnrichmentException(ex);
             }
         }
+
+        // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+        // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+        static bool TryFetchRequest(object payload, out HttpRequestMessage request)
+        {
+            if (!StartRequestFetcher.TryFetch(payload, out request) || request == null)
+            {
+                return false;
+            }
+
+            return true;
+        }
     }
 
     public void OnStopActivity(Activity activity, object payload)
     {
         if (activity.IsAllDataRequested)
         {
-            // https://github.com/dotnet/runtime/blob/master/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs
-            // requestTaskStatus is not null
-            _ = this.stopRequestStatusFetcher.TryFetch(payload, out var requestTaskStatus);
+            var requestTaskStatus = GetRequestStatus(payload);
 
             ActivityStatusCode currentStatusCode = activity.Status;
             if (requestTaskStatus != TaskStatus.RanToCompletion)
@@ -241,7 +257,7 @@ public void OnStopActivity(Activity activity, object payload)
                 }
             }
 
-            if (this.stopResponseFetcher.TryFetch(payload, out HttpResponseMessage response) && response != null)
+            if (TryFetchResponse(payload, out HttpResponseMessage response))
             {
                 if (this.emitOldAttributes)
                 {
@@ -267,14 +283,43 @@ public void OnStopActivity(Activity activity, object payload)
                     HttpInstrumentationEventSource.Log.EnrichmentException(ex);
                 }
             }
+
+            // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+            // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+            [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+            static TaskStatus GetRequestStatus(object payload)
+            {
+                // requestTaskStatus (type is TaskStatus) is a non-nullable enum so we don't need to have a null check here.
+                // See: https://github.com/dotnet/runtime/blob/79c021d65c280020246d1035b0e87ae36f2d36a9/src/libraries/System.Net.Http/src/HttpDiagnosticsGuide.md?plain=1#L69
+                _ = StopRequestStatusFetcher.TryFetch(payload, out var requestTaskStatus);
+
+                return requestTaskStatus;
+            }
+        }
+
+        // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+        // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+        static bool TryFetchResponse(object payload, out HttpResponseMessage response)
+        {
+            if (StopResponseFetcher.TryFetch(payload, out response) && response != null)
+            {
+                return true;
+            }
+
+            return false;
         }
     }
 
     public void OnException(Activity activity, object payload)
     {
         if (activity.IsAllDataRequested)
         {
-            if (!this.stopExceptionFetcher.TryFetch(payload, out Exception exc) || exc == null)
+            if (!TryFetchException(payload, out Exception exc))
             {
                 HttpInstrumentationEventSource.Log.NullPayload(nameof(HttpHandlerDiagnosticListener), nameof(this.OnException));
                 return;
@@ -299,5 +344,20 @@ public void OnException(Activity activity, object payload)
                 HttpInstrumentationEventSource.Log.EnrichmentException(ex);
             }
         }
+
+        // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+        // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+        static bool TryFetchException(object payload, out Exception exc)
+        {
+            if (!StopExceptionFetcher.TryFetch(payload, out exc) || exc == null)
+            {
+                return false;
+            }
+
+            return true;
+        }
     }
 }

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs

@@ -15,6 +15,9 @@
 // </copyright>
 
 using System.Diagnostics;
+#if NET6_0_OR_GREATER
+using System.Diagnostics.CodeAnalysis;
+#endif
 using System.Diagnostics.Metrics;
 #if NETFRAMEWORK
 using System.Net.Http;
@@ -28,8 +31,8 @@ internal sealed class HttpHandlerMetricsDiagnosticListener : ListenerHandler
 {
     internal const string OnStopEvent = "System.Net.Http.HttpRequestOut.Stop";
 
-    private readonly PropertyFetcher<HttpResponseMessage> stopResponseFetcher = new("Response");
-    private readonly PropertyFetcher<HttpRequestMessage> stopRequestFetcher = new("Request");
+    private static readonly PropertyFetcher<HttpResponseMessage> StopResponseFetcher = new("Response");
+    private static readonly PropertyFetcher<HttpRequestMessage> StopRequestFetcher = new("Request");
     private readonly Histogram<double> httpClientDuration;
     private readonly HttpClientMetricInstrumentationOptions options;
     private readonly bool emitOldAttributes;
@@ -56,7 +59,7 @@ public override void OnEventWritten(string name, object payload)
             }
 
             var activity = Activity.Current;
-            if (this.stopRequestFetcher.TryFetch(payload, out HttpRequestMessage request) && request != null)
+            if (TryFetchRequest(payload, out HttpRequestMessage request))
             {
                 TagList tags = default;
 
@@ -73,7 +76,7 @@ public override void OnEventWritten(string name, object payload)
                         tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeNetPeerPort, request.RequestUri.Port));
                     }
 
-                    if (this.stopResponseFetcher.TryFetch(payload, out HttpResponseMessage response) && response != null)
+                    if (TryFetchResponse(payload, out HttpResponseMessage response))
                     {
                         tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeHttpStatusCode, TelemetryHelper.GetBoxedStatusCode(response.StatusCode)));
                     }
@@ -91,7 +94,7 @@ public override void OnEventWritten(string name, object payload)
                         tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeServerPort, request.RequestUri.Port));
                     }
 
-                    if (this.stopResponseFetcher.TryFetch(payload, out HttpResponseMessage response) && response != null)
+                    if (TryFetchResponse(payload, out HttpResponseMessage response))
                     {
                         tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeHttpResponseStatusCode, TelemetryHelper.GetBoxedStatusCode(response.StatusCode)));
                     }
@@ -103,5 +106,21 @@ public override void OnEventWritten(string name, object payload)
                 this.httpClientDuration.Record(activity.Duration.TotalMilliseconds, tags);
             }
         }
+
+        // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+        // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+        static bool TryFetchRequest(object payload, out HttpRequestMessage request) =>
+            StopRequestFetcher.TryFetch(payload, out request) && request != null;
+
+        // The AOT-annotation DynamicallyAccessedMembers in System.Net.Http library ensures that top-level properties on the payload object are always preserved.
+        // see https://github.com/dotnet/runtime/blob/f9246538e3d49b90b0e9128d7b1defef57cd6911/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs#L325
+#if NET6_0_OR_GREATER
+        [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "The event source guarantees that top-level properties are preserved")]
+#endif
+        static bool TryFetchResponse(object payload, out HttpResponseMessage response) =>
+            StopResponseFetcher.TryFetch(payload, out response) && response != null;
     }
 }