[Core] Adding attributes to support Native AOT compiling (Azure#37734)

* part 1

* additional changes

* additional attributes

* additional attributes

* adding diagnosticscope attributes

* updating messages

* more fixes

* additional updates

* updates

* PR feedback

* API update

* removing unnecessary warnings

* reverting attribute on HttpPipelineSynchronousPolicy

* update api

* updates

* update

* API export

* WIP fix 1

* WIP

* attribute adjustments

* adding compatibility test

* WIP adding test

* WIP API

* WIP

* WIP

* updates

* add test script and remove #if statements

* fixing build

* Update Program.cs

* adding some compile statements

* Update AzureCoreEventSource.cs

* build fix attempt

* fix built attempt 2

* Update MutableJsonChange.cs

* Update MutableJsonChange.cs

* Update MutableJsonDocument.cs

* Update HttpPipelineSynchronousPolicy.cs

* adding comments

* PR fb 1

* test

* test2

* test3

* attempt

* additional build fixes

* Remove comment

* PR feedback + fixing impacts of feedback changes

* fixes

* Update GeoRedundantFallbackPolicy.cs

* Update GeoRedundantFallbackPolicy.cs

* Update GeoRedundantFallbackPolicy.cs

* fix

* add tests

* pipeline fixes

* update comments

* feedback

* adjustments

* adjustment

* pipeline fix

* PR feedback 1

* Apply suggestions from code review

Co-authored-by: Vitek Karas <10670590+vitek-karas@users.noreply.github.com>

* PR feedback updates 2

* Update sdk/core/Azure.Core/src/Shared/DiagnosticScope.cs

Co-authored-by: Vitek Karas <10670590+vitek-karas@users.noreply.github.com>

* need one other suppression

* remove 2 annotations + update suppression message

* removing all attributes from RequestContentHelper

* tweak justification

* removing test project from Azure.Core, will be adding feedback to general CI pipeline

* WIP

* feedback

* Update sdk/core/Azure.Core/src/Shared/DiagnosticScope.cs

Co-authored-by: Anne Thompson <annelo@microsoft.com>

* fix attribute and add comments

* Addressing feedback

* adding net 5 preprocessor directives

* Update sdk/core/Azure.Core/src/DynamicData/MutableJsonElement.cs

Co-authored-by: Vitek Karas <10670590+vitek-karas@users.noreply.github.com>

* remove unused const

* pipeline fix

---------

Co-authored-by: Vitek Karas <10670590+vitek-karas@users.noreply.github.com>
Co-authored-by: Anne Thompson <annelo@microsoft.com>

eng/Directory.Build.Common.targets

@@ -201,6 +201,7 @@
     <Compile Include="$(AzureCoreSharedSources)ChangeTrackingDictionary.cs" LinkBase="Shared/Core" />
     <Compile Include="$(AzureCoreSharedSources)ChangeTrackingList.cs" LinkBase="Shared/Core" />
     <Compile Include="$(AzureCoreSharedSources)ClientDiagnostics.cs" LinkBase="Shared/Core" />
+		<Compile Include="$(AzureCoreSharedSources)TrimmingAttribute.cs" LinkBase="Shared/Core" />
     <Compile Include="$(AzureCoreSharedSources)DiagnosticScope.cs" LinkBase="Shared/Core" />
     <Compile Include="$(AzureCoreSharedSources)DiagnosticScopeFactory.cs" LinkBase="Shared/Core" />
     <Compile Include="$(AzureCoreSharedSources)FixedDelayWithNoJitterStrategy.cs" LinkBase="Shared/Core" />

sdk/core/Azure.Core.Expressions.DataFactory/src/Azure.Core.Expressions.DataFactory.csproj

@@ -32,6 +32,7 @@
     <Compile Include="$(AzureCoreSharedSources)PropertyReferenceTypeAttribute.cs" LinkBase="Shared\Core" />
     <Compile Include="$(AzureCoreSharedSources)InitializationConstructorAttribute.cs" LinkBase="Shared\Core" />
     <Compile Include="$(AzureCoreSharedSources)SerializationConstructorAttribute.cs" LinkBase="Shared\Core" />
+    <Compile Include="$(AzureCoreSharedSources)TrimmingAttribute.cs" LinkBase="Shared\Core" />
   </ItemGroup>
 
 </Project>

sdk/core/Azure.Core/api/Azure.Core.net5.0.cs

@@ -544,8 +544,11 @@ protected RequestContent() { }
         public static Azure.Core.RequestContent Create(byte[] bytes) { throw null; }
         public static Azure.Core.RequestContent Create(byte[] bytes, int index, int length) { throw null; }
         public static Azure.Core.RequestContent Create(System.IO.Stream stream) { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable) { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable, Azure.Core.Serialization.JsonPropertyNames propertyNameFormat, string dateTimeFormat = "o") { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable, Azure.Core.Serialization.ObjectSerializer? serializer) { throw null; }
         public static Azure.Core.RequestContent Create(System.ReadOnlyMemory<byte> bytes) { throw null; }
         public static Azure.Core.RequestContent Create(string content) { throw null; }

sdk/core/Azure.Core/api/Azure.Core.net6.0.cs

@@ -544,8 +544,11 @@ protected RequestContent() { }
         public static Azure.Core.RequestContent Create(byte[] bytes) { throw null; }
         public static Azure.Core.RequestContent Create(byte[] bytes, int index, int length) { throw null; }
         public static Azure.Core.RequestContent Create(System.IO.Stream stream) { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable) { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable, Azure.Core.Serialization.JsonPropertyNames propertyNameFormat, string dateTimeFormat = "o") { throw null; }
+        [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This method uses reflection-based serialization which is incompatible with trimming. Try using one of the 'Create' overloads that doesn't wrap a serialized version of an object.")]
         public static Azure.Core.RequestContent Create(object serializable, Azure.Core.Serialization.ObjectSerializer? serializer) { throw null; }
         public static Azure.Core.RequestContent Create(System.ReadOnlyMemory<byte> bytes) { throw null; }
         public static Azure.Core.RequestContent Create(string content) { throw null; }
@@ -1024,6 +1027,7 @@ protected HttpPipelinePolicy() { }
         protected static void ProcessNext(Azure.Core.HttpMessage message, System.ReadOnlyMemory<Azure.Core.Pipeline.HttpPipelinePolicy> pipeline) { }
         protected static System.Threading.Tasks.ValueTask ProcessNextAsync(Azure.Core.HttpMessage message, System.ReadOnlyMemory<Azure.Core.Pipeline.HttpPipelinePolicy> pipeline) { throw null; }
     }
+    [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembersAttribute(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicMethods)]
     public abstract partial class HttpPipelineSynchronousPolicy : Azure.Core.Pipeline.HttpPipelinePolicy
     {
         protected HttpPipelineSynchronousPolicy() { }
@@ -1075,6 +1079,7 @@ public ServerCertificateCustomValidationArgs(System.Security.Cryptography.X509Ce
 }
 namespace Azure.Core.Serialization
 {
+    [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This class utilizes reflection-based JSON serialization and deserialization which is not compatible with trimming.")]
     [System.Diagnostics.DebuggerDisplayAttribute("{DebuggerDisplay,nq}")]
     public sealed partial class DynamicData : System.Dynamic.IDynamicMetaObjectProvider, System.IDisposable
     {
@@ -1109,6 +1114,7 @@ public partial interface IMemberNameConverter
     {
         string? ConvertMemberName(System.Reflection.MemberInfo member);
     }
+    [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("This class uses reflection-based JSON serialization and deserialization that is not compatible with trimming.")]
     public partial class JsonObjectSerializer : Azure.Core.Serialization.ObjectSerializer, Azure.Core.Serialization.IMemberNameConverter
     {
         public JsonObjectSerializer() { }

sdk/core/Azure.Core/src/Diagnostics/AzureCoreEventSource.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Tracing;
+using System.Diagnostics.CodeAnalysis;
 using System.Text;
 
 namespace Azure.Core.Diagnostics
@@ -231,6 +232,7 @@ public void ErrorResponseContentTextBlock(string requestId, int blockNumber, str
         }
 
         [Event(RequestRetryingEvent, Level = EventLevel.Informational, Message = "Request [{0}] attempt number {1} took {2:00.0}s")]
+        [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026", Justification = "WriteEvent is used with primitive types.")]
         public void RequestRetrying(string requestId, int retryNumber, double seconds)
         {
             WriteEvent(RequestRetryingEvent, requestId, retryNumber, seconds);

sdk/core/Azure.Core/src/DynamicData/DynamicData.cs

@@ -6,8 +6,10 @@
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Text.Json;
 using System.Text.Json.Serialization;
 using Azure.Core.Json;
@@ -20,6 +22,10 @@ namespace Azure.Core.Serialization
     /// This and related types are not intended to be mocked.
     /// </summary>
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+    [RequiresUnreferencedCode(MutableJsonDocument.SerializationRequiresUnreferencedCodeClass)]
+    [RequiresDynamicCode(MutableJsonDocument.SerializationRequiresUnreferencedCodeClass)]
+#endif
     [JsonConverter(typeof(DynamicDataJsonConverter))]
     public sealed partial class DynamicData : IDisposable
     {
@@ -33,6 +39,8 @@ public sealed partial class DynamicData : IDisposable
         private readonly DynamicDataOptions _options;
         private readonly JsonSerializerOptions _serializerOptions;
 
+        internal const string SerializationRequiresUnreferencedCodeClass = "This class utilizes reflection-based JSON serialization and deserialization which is not compatible with trimming.";
+
         internal DynamicData(MutableJsonElement element, DynamicDataOptions options)
         {
             _element = element;
@@ -471,8 +479,14 @@ public override int GetHashCode()
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
         private string DebuggerDisplay => _element.DebuggerDisplay;
 
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+        [RequiresUnreferencedCode(ClassIsIncompatibleWithTrimming)]
+#endif
+        [RequiresDynamicCode(ClassIsIncompatibleWithTrimming)]
         private class DynamicDataJsonConverter : JsonConverter<DynamicData>
         {
+            public const string ClassIsIncompatibleWithTrimming = "Using DynamicData or DynamicDataConverter is not compatible with trimming due to reflection-based serialization.";
+
             public override DynamicData Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
             {
                 MutableJsonDocument mdoc = MutableJsonDocument.Parse(ref reader);

sdk/core/Azure.Core/src/DynamicData/MutableJsonChange.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 
 #nullable enable

sdk/core/Azure.Core/src/DynamicData/MutableJsonDocument.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Buffers;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Text;
 using System.Text.Json;
@@ -15,6 +16,13 @@ namespace Azure.Core.Json
     /// <summary>
     /// A mutable representation of a JSON value.
     /// </summary>
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+    // This class is marked as RequiresUnreferencedCode and RequiresDynamic code for two reasons. First, for the usage of MutableJsonElement in RootElement and WriteTo. Second, the method WriteTo
+    // is  used in the MutableJsonDocumentConverter, which causes MutableJsonDocumentConverter to be incompatible with trimming. Since the class is used in the attribute on this class, the entire
+    // class must be annotated.
+    [RequiresUnreferencedCode(SerializationRequiresUnreferencedCodeClass)]
+    [RequiresDynamicCode(SerializationRequiresUnreferencedCodeClass)]
+#endif
     [JsonConverter(typeof(MutableJsonDocumentConverter))]
     internal sealed partial class MutableJsonDocument : IDisposable
     {
@@ -26,6 +34,8 @@ internal sealed partial class MutableJsonDocument : IDisposable
         private readonly JsonSerializerOptions _serializerOptions;
         internal JsonSerializerOptions SerializerOptions => _serializerOptions;
 
+        internal const string SerializationRequiresUnreferencedCodeClass = "This class utilizes reflection-based JSON serialization and deserialization which is not compatible with trimming.";
+
         private ChangeTracker? _changeTracker;
         internal ChangeTracker Changes
         {
@@ -210,8 +220,14 @@ private MutableJsonDocument(JsonDocument document, ReadOnlyMemory<byte> utf8Json
             _serializerOptions = serializerOptions ?? DefaultSerializerOptions;
         }
 
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+        [RequiresUnreferencedCode(classIsIncompatibleWithTrimming)]
+#endif
+        [RequiresDynamicCode(classIsIncompatibleWithTrimming)]
         private class MutableJsonDocumentConverter : JsonConverter<MutableJsonDocument>
         {
+            public const string classIsIncompatibleWithTrimming = "Using MutableJsonDocument or MutableJsonDocumentConverter is not compatible with trimming due to reflection-based serialization.";
+
             public override MutableJsonDocument Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
             {
                 return Parse(ref reader);

sdk/core/Azure.Core/src/DynamicData/MutableJsonElement.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Buffers;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Text;
 using System.Text.Json;
@@ -17,6 +18,12 @@ namespace Azure.Core.Json
     /// A mutable representation of a JSON element.
     /// </summary>
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
+    // This struct is incompatible with trimming for a couple reasons:
+    //   1. MutableJsonElementConverter is not compatible with trimming, since it is used in an attribute, the whole struct is incompatible with trimming.
+    //   2. The internal static method SerializeToJsonElement uses reflection-based serialization. This method is used throughout the non-static methods within this struct.
+    // In order to avoid annotating every single method, we are instead annotating the constructor, and the problematic static method.
+    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026", Justification = "The constructor is marked as RequiresUnreferencedCode, since the whole struct is incompatible with trimming.")]
+    [UnconditionalSuppressMessage("ReflectionAnalysis", "IL3050", Justification = "The constructor is marked as RequiresDynamicCode, since the whole struct is incompatible with AOT.")]
     [JsonConverter(typeof(MutableJsonElementConverter))]
     internal readonly partial struct MutableJsonElement
     {
@@ -27,8 +34,15 @@ internal readonly partial struct MutableJsonElement
         private readonly string _path;
         private readonly int _highWaterMark;
 
+        internal const string SerializationRequiresUnreferencedCodeConstructor = "This struct utilizes reflection-based JSON serialization which is not compatible with trimming.";
+        internal const string SerializationRequiresUnreferencedCodeMethod = "This method utilizes reflection-based JSON serialization which is not compatible with trimming.";
+
         private readonly MutableJsonDocument.ChangeTracker Changes => _root.Changes;
 
+        // The default constructor generated by the compiler should also be annotated - but since this struct cannot function if the default constructor is used, it is okay that
+        // only this constructor is annotated.
+        [RequiresUnreferencedCode(SerializationRequiresUnreferencedCodeConstructor)]
+        [RequiresDynamicCode(SerializationRequiresUnreferencedCodeConstructor)]
         internal MutableJsonElement(MutableJsonDocument root, JsonElement element, string path, int highWaterMark = -1)
         {
             _element = element;
@@ -1302,6 +1316,10 @@ public override string ToString()
             return _element.ToString() ?? "null";
         }
 
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+        [RequiresUnreferencedCode(SerializationRequiresUnreferencedCodeMethod)]
+        [RequiresDynamicCode(SerializationRequiresUnreferencedCodeMethod)]
+#endif
         internal static JsonElement SerializeToJsonElement(object? value, JsonSerializerOptions? options = default)
         {
             byte[] bytes = JsonSerializer.SerializeToUtf8Bytes(value, options);
@@ -1395,6 +1413,9 @@ private void EnsureValid()
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
         internal string DebuggerDisplay => $"ValueKind = {ValueKind} : \"{ToString()}\"";
 
+#if !NET5_0 // RequiresUnreferencedCode in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+        [RequiresUnreferencedCode("Using MutableJsonElement or MutableJsonElementConverter is not compatible with trimming due to reflection-based serialization.")]
+#endif
         private class MutableJsonElementConverter : JsonConverter<MutableJsonElement>
         {
             public override MutableJsonElement Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)

sdk/core/Azure.Core/src/Pipeline/HttpPipelineSynchronousPolicy.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 using System.Threading.Tasks;
 
@@ -11,6 +12,9 @@ namespace Azure.Core.Pipeline
     /// <summary>
     /// Represents a <see cref="HttpPipelinePolicy"/> that doesn't do any asynchronous or synchronously blocking operations.
     /// </summary>
+#if !NET5_0 // DynamicallyAccessedMembers in net5.0 doesn't have AttributeTargets.Class as a target, but it was added in net6.0
+    [DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicMethods)]
+#endif
     public abstract class HttpPipelineSynchronousPolicy : HttpPipelinePolicy
     {
         private static Type[] _onReceivedResponseParameters = new[] { typeof(HttpMessage) };

sdk/core/Azure.Core/src/Pipeline/Internal/RequestActivityPolicy.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Threading.Tasks;
 
@@ -58,11 +59,7 @@ public override void Process(HttpMessage message, ReadOnlyMemory<HttpPipelinePol
 
         private async ValueTask ProcessAsync(HttpMessage message, ReadOnlyMemory<HttpPipelinePolicy> pipeline, bool async)
         {
-#if NETCOREAPP2_1
-            using var scope = new DiagnosticScope("Azure.Core.Http.Request", s_diagnosticSource, message, s_activitySource, DiagnosticScope.ActivityKind.Client, false);
-#else
-            using var scope = new DiagnosticScope("Azure.Core.Http.Request", s_diagnosticSource, message, s_activitySource, System.Diagnostics.ActivityKind.Client, false);
-#endif
+            using var scope = CreateDiagnosticScope(message);
 
             bool isActivitySourceEnabled = IsActivitySourceEnabled;
 
@@ -136,6 +133,16 @@ private async ValueTask ProcessAsync(HttpMessage message, ReadOnlyMemory<HttpPip
             }
         }
 
+        [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026", Justification = "The values being passed into Write have the commonly used properties being preserved with DynamicallyAccessedMembers.")]
+        private DiagnosticScope CreateDiagnosticScope<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicProperties)] T>(T sourceArgs)
+        {
+#if NETCOREAPP2_1
+            return new DiagnosticScope("Azure.Core.Http.Request", s_diagnosticSource, sourceArgs, s_activitySource, DiagnosticScope.ActivityKind.Client, false);
+#else
+            return new DiagnosticScope("Azure.Core.Http.Request", s_diagnosticSource, sourceArgs, s_activitySource, System.Diagnostics.ActivityKind.Client, false);
+#endif
+        }
+
         private static ValueTask ProcessNextAsync(HttpMessage message, ReadOnlyMemory<HttpPipelinePolicy> pipeline, bool async)
         {
             Activity? currentActivity = Activity.Current;