.Net: Address IL2067 and IL3051 AOT warnings in Abstractions project (#…

…9011)

### Motivation, Context and Description
This PR addresses the last two IL2067 and IL3051 AOT warnings in the
Abstractions project. It also adds the testing app that uses .NET’s AOT
compiler to analyze SK projects and ensure all AOT related warnings are
found. You can find more details here: -
https://devblogs.microsoft.com/dotnet/creating-aot-compatible-libraries/#analyzing-.net-libraries.

dotnet/SK-dotnet.sln

@@ -108,15 +108,15 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Diagnostics", "Diagnostics", "{29E7D971-1308-4171-9872-E8E4669A1134}"
 	ProjectSection(SolutionItems) = preProject
 		src\InternalUtilities\src\Diagnostics\CompilerServicesAttributes.cs = src\InternalUtilities\src\Diagnostics\CompilerServicesAttributes.cs
+		src\InternalUtilities\src\Diagnostics\DynamicallyAccessedMembersAttribute.cs = src\InternalUtilities\src\Diagnostics\DynamicallyAccessedMembersAttribute.cs
 		src\InternalUtilities\src\Diagnostics\ExceptionExtensions.cs = src\InternalUtilities\src\Diagnostics\ExceptionExtensions.cs
 		src\InternalUtilities\src\Diagnostics\ExperimentalAttribute.cs = src\InternalUtilities\src\Diagnostics\ExperimentalAttribute.cs
 		src\InternalUtilities\src\Diagnostics\IsExternalInit.cs = src\InternalUtilities\src\Diagnostics\IsExternalInit.cs
 		src\InternalUtilities\src\Diagnostics\NullableAttributes.cs = src\InternalUtilities\src\Diagnostics\NullableAttributes.cs
-		src\InternalUtilities\src\Diagnostics\Verify.cs = src\InternalUtilities\src\Diagnostics\Verify.cs
-		src\InternalUtilities\src\Diagnostics\DynamicallyAccessedMembersAttribute.cs = src\InternalUtilities\src\Diagnostics\DynamicallyAccessedMembersAttribute.cs
 		src\InternalUtilities\src\Diagnostics\RequiresDynamicCodeAttribute.cs = src\InternalUtilities\src\Diagnostics\RequiresDynamicCodeAttribute.cs
 		src\InternalUtilities\src\Diagnostics\RequiresUnreferencedCodeAttribute.cs = src\InternalUtilities\src\Diagnostics\RequiresUnreferencedCodeAttribute.cs
 		src\InternalUtilities\src\Diagnostics\UnconditionalSuppressMessageAttribute.cs = src\InternalUtilities\src\Diagnostics\UnconditionalSuppressMessageAttribute.cs
+		src\InternalUtilities\src\Diagnostics\Verify.cs = src\InternalUtilities\src\Diagnostics\Verify.cs
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Linq", "Linq", "{B00AD427-0047-4850-BEF9-BA8237EA9D8B}"
@@ -364,7 +364,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Process.LocalRuntime", "src
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Process.UnitTests", "src\Experimental\Process.UnitTests\Process.UnitTests.csproj", "{21A32285-8443-4A75-B2E8-27E6090EC562}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GettingStartedWithProcesses", "samples\GettingStartedWithProcesses\GettingStartedWithProcesses.csproj", "{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GettingStartedWithProcesses", "samples\GettingStartedWithProcesses\GettingStartedWithProcesses.csproj", "{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AotCompatibility.TestApp", "samples\Demos\AotCompatibility.TestApp\AotCompatibility.TestApp.csproj", "{6ECFDF04-2237-4A85-B114-DAA34923E9E6}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -931,6 +933,12 @@ Global
 		{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7}.Publish|Any CPU.Build.0 = Debug|Any CPU
 		{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Publish|Any CPU.ActiveCfg = Publish|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Publish|Any CPU.Build.0 = Publish|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1059,8 +1067,9 @@ Global
 		{27AF60D6-86F5-4591-A700-4F8C93F41B11} = {0D8C6358-5DAA-4EA6-A924-C268A9A21BC9}
 		{21A32285-8443-4A75-B2E8-27E6090EC562} = {0D8C6358-5DAA-4EA6-A924-C268A9A21BC9}
 		{C057ACDF-DDD8-496B-BAF9-1C6E4E1248D7} = {FA3720F1-C99A-49B2-9577-A940257098BF}
+		{6ECFDF04-2237-4A85-B114-DAA34923E9E6} = {5D4C0700-BBB5-418F-A7B2-F392B9A18263}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {FBDC56A3-86AD-4323-AA0F-201E59123B83}
 	EndGlobalSection
-EndGlobal
+EndGlobal

dotnet/samples/Demos/AotCompatibility.TestApp/AotCompatibility.TestApp.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <PublishAot>true</PublishAot>
+    <TrimmerSingleWarn>false</TrimmerSingleWarn>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\src\SemanticKernel.Abstractions\SemanticKernel.Abstractions.csproj" />
+  </ItemGroup>
+
+</Project>

dotnet/samples/Demos/AotCompatibility.TestApp/Program.cs

@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+namespace AotCompatibility.TestApp;
+
+internal static class Program
+{
+    private static void Main(string[] args)
+    {
+        Console.WriteLine("Hello, World!");
+    }
+}

dotnet/src/InternalUtilities/src/System/InternalTypeConverter.cs

@@ -38,17 +38,19 @@ internal static class InternalTypeConverter
     /// </summary>
     /// <param name="sourceType">The source Type for which to retrieve the type-to-string converter delegate.</param>
     /// <returns>A Func delegate for converting the source type to a string, considering CultureInfo, or null if no suitable converter is found.</returns>
-    private static Func<object?, CultureInfo, string?>? GetTypeToStringConverterDelegate(Type sourceType) =>
-        s_converters.GetOrAdd(sourceType, static sourceType =>
+    private static Func<object?, CultureInfo, string?>? GetTypeToStringConverterDelegate(
+        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor | DynamicallyAccessedMemberTypes.PublicFields)] Type sourceType) =>
+        s_converters.GetOrAdd(sourceType, (
+            [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor | DynamicallyAccessedMemberTypes.PublicFields)] Type innerSourceType) =>
         {
             // Strings just render as themselves.
-            if (sourceType == typeof(string))
+            if (innerSourceType == typeof(string))
             {
                 return (input, cultureInfo) => (string)input!;
             }
 
             // Look up and use a type converter.
-            if (TypeConverterFactory.GetTypeConverter(sourceType) is TypeConverter converter && converter.CanConvertTo(typeof(string)))
+            if (TypeConverterFactory.GetTypeConverter(innerSourceType) is TypeConverter converter && converter.CanConvertTo(typeof(string)))
             {
                 return (input, cultureInfo) =>
                 {

dotnet/src/InternalUtilities/src/System/TypeConverterFactory.cs

@@ -18,7 +18,8 @@ internal static class TypeConverterFactory
     /// </summary>
     /// <param name="type">The Type of the object to convert.</param>
     /// <returns>A TypeConverter instance if a suitable converter is found, otherwise null.</returns>
-    internal static TypeConverter? GetTypeConverter(Type type)
+    internal static TypeConverter? GetTypeConverter(
+        [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor | DynamicallyAccessedMemberTypes.PublicFields)] Type type)
     {
         // In an ideal world, this would use TypeDescriptor.GetConverter. However, that is not friendly to
         // any form of ahead-of-time compilation, as it could end up requiring functionality that was trimmed.

dotnet/src/SemanticKernel.Abstractions/Services/EmptyServiceProvider.cs

@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.SemanticKernel;
@@ -32,9 +33,29 @@ public object GetRequiredKeyedService(Type serviceType, object? serviceKey) =>
         if (serviceType.IsConstructedGenericType &&
             serviceType.GetGenericTypeDefinition() == typeof(IEnumerable<>))
         {
-            return Array.CreateInstance(serviceType.GenericTypeArguments[0], 0);
+            return CreateArray(serviceType.GenericTypeArguments[0], 0);
         }
 
         return null;
     }
+
+    [UnconditionalSuppressMessage("AotAnalysis", "IL3050:RequiresDynamicCode", Justification = "VerifyAotCompatibility ensures elementType is not a ValueType")]
+    private static Array CreateArray(Type elementType, int length)
+    {
+        if (VerifyAotCompatibility && elementType.IsValueType)
+        {
+            // NativeAOT apps are not able to make Enumerable of ValueType services
+            // since there is no guarantee the ValueType[] code has been generated.
+            throw new InvalidOperationException($"Unable to create an Enumerable service of type '{elementType}' because it is a ValueType. Native code to support creating Enumerable services might not be available with native AOT.");
+        }
+
+        return Array.CreateInstance(elementType, length);
+    }
+
+    private static bool VerifyAotCompatibility =>
+#if NETFRAMEWORK || NETSTANDARD2_0
+            false;
+#else
+            !System.Runtime.CompilerServices.RuntimeFeature.IsDynamicCodeSupported;
+#endif
 }