.Net: Make ONNX connector Native-AOT compatible. (#9192)

### Motivation and Context
This PR makes the ONNX connector Native-AOT friendly, allowing it to be
used in applications targeting Native-AOT.

### Description
- Adds a new parameter of `JsonSerializerOptions` type to the
constructor of the `OnnxRuntimeGenAIChatCompletionService` class and a
few extension methods.
- Adds a new
`OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings` method
that accepts JSOs to serialize prompt execution settings type of which
is not known in advance.
- Makes function choice behavior classes public, allowing the source
generator to access them and not fail with the error:
"_dotnet\src\Connectors\Connectors.Onnx\Text\OnnxRuntimeGenAIPromptExecutionSettingsJsonSerializerContext
- Copy.cs(10,31,10,91): warning SYSLIB1222: The constructor on type
'Microsoft.SemanticKernel.AutoFunctionChoiceBehavior' has been annotated
with JsonConstructorAttribute but is not accessible by the source
generator.
(https://learn.microsoft.com/dotnet/fundamentals/syslib-diagnostics/syslib1222)_"

CC: @eiriktsarpalis

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

@@ -12,8 +12,10 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\src\SemanticKernel.Abstractions\SemanticKernel.Abstractions.csproj" />
     <ProjectReference Include="..\..\..\src\SemanticKernel.Core\SemanticKernel.Core.csproj" />
+    <ProjectReference Include="..\..\..\src\Connectors\Connectors.Onnx\Connectors.Onnx.csproj" />
     <TrimmerRootAssembly Include="Microsoft.SemanticKernel.Abstractions" />
     <TrimmerRootAssembly Include="Microsoft.SemanticKernel.Core" />
+    <TrimmerRootAssembly Include="Microsoft.SemanticKernel.Connectors.Onnx" />
   </ItemGroup>
 
 </Project>

dotnet/src/Connectors/Connectors.Onnx.UnitTests/CustomPromptExecutionSettings.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json.Serialization;
+using Microsoft.SemanticKernel;
+
+namespace SemanticKernel.Connectors.Onnx.UnitTests;
+
+internal sealed class CustomPromptExecutionSettings : PromptExecutionSettings
+{
+    /// <summary>
+    /// Temperature to sample with.
+    /// </summary>
+    [JsonPropertyName("temperature")]
+    public float? Temperature { get; set; }
+}

dotnet/src/Connectors/Connectors.Onnx.UnitTests/CustomPromptExecutionSettingsJsonSerializerContext.cs

@@ -0,0 +1,10 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json.Serialization;
+
+namespace SemanticKernel.Connectors.Onnx.UnitTests;
+
+[JsonSerializable(typeof(CustomPromptExecutionSettings))]
+internal sealed partial class CustomPromptExecutionSettingsJsonSerializerContext : JsonSerializerContext
+{
+}

dotnet/src/Connectors/Connectors.Onnx.UnitTests/OnnxRuntimeGenAIPromptExecutionSettingsTests.cs

@@ -94,4 +94,37 @@ public void FromExecutionSettingsWhenSerializedHasPropertiesShouldPopulateSpecia
         Assert.False(onnxExecutionSettings.EarlyStopping);
         Assert.True(onnxExecutionSettings.DoSample);
     }
+
+    [Fact]
+    public void ItShouldCreateOnnxPromptExecutionSettingsFromCustomPromptExecutionSettings()
+    {
+        // Arrange
+        var customExecutionSettings = new CustomPromptExecutionSettings() { ServiceId = "service-id", Temperature = 36.6f };
+
+        // Act
+        var onnxExecutionSettings = OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings(customExecutionSettings);
+
+        // Assert
+        Assert.Equal("service-id", onnxExecutionSettings.ServiceId);
+        Assert.Equal(36.6f, onnxExecutionSettings.Temperature);
+    }
+
+    [Fact]
+    public void ItShouldCreateOnnxPromptExecutionSettingsFromCustomPromptExecutionSettingsUsingJSOs()
+    {
+        // Arrange
+        var jsos = new JsonSerializerOptions
+        {
+            TypeInfoResolver = CustomPromptExecutionSettingsJsonSerializerContext.Default
+        };
+
+        var customExecutionSettings = new CustomPromptExecutionSettings() { ServiceId = "service-id", Temperature = 36.6f };
+
+        // Act
+        var onnxExecutionSettings = OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings(customExecutionSettings, jsos);
+
+        // Assert
+        Assert.Equal("service-id", onnxExecutionSettings.ServiceId);
+        Assert.Equal(36.6f, onnxExecutionSettings.Temperature);
+    }
 }

dotnet/src/Connectors/Connectors.Onnx/Connectors.Onnx.csproj

@@ -6,11 +6,24 @@
     <RootNamespace>$(AssemblyName)</RootNamespace>
     <TargetFrameworks>net8.0;netstandard2.0</TargetFrameworks>
     <VersionSuffix>alpha</VersionSuffix>
+    <IsAotCompatible Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">true</IsAotCompatible>
   </PropertyGroup>
 
   <!-- IMPORT NUGET PACKAGE SHARED PROPERTIES -->
   <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
-  <Import Project="$(RepoRoot)/dotnet/src/InternalUtilities/src/InternalUtilities.props" />
+
+  <ItemGroup>
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/Verify.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/NullableAttributes.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/ExperimentalAttribute.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/CompilerServicesAttributes.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/IsExternalInit.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/RequiresUnreferencedCodeAttribute.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/RequiresDynamicCodeAttribute.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Diagnostics/UnconditionalSuppressMessageAttribute.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/Text/JsonOptionsCache.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+    <Compile Include="$(RepoRoot)/dotnet/src/InternalUtilities/src/System/AppContextSwitchHelper.cs" Link="%(RecursiveDir)%(Filename)%(Extension)" />
+  </ItemGroup>
 
   <PropertyGroup>
     <Title>Semantic Kernel - ONNX Connectors</Title>
@@ -19,7 +32,6 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\SemanticKernel.Core\SemanticKernel.Core.csproj" />
-
     <PackageReference Include="FastBertTokenizer" />
     <PackageReference Include="Microsoft.ML.OnnxRuntime" />
     <PackageReference Include="System.Numerics.Tensors" />

dotnet/src/Connectors/Connectors.Onnx/OnnxKernelBuilderExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System.IO;
+using System.Text.Json;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.SemanticKernel.ChatCompletion;
@@ -23,18 +24,21 @@ public static class OnnxKernelBuilderExtensions
     /// <param name="modelId">Model Id.</param>
     /// <param name="modelPath">The generative AI ONNX model path.</param>
     /// <param name="serviceId">The optional service ID.</param>
+    /// <param name="jsonSerializerOptions">The <see cref="JsonSerializerOptions"/> to use for various aspects of serialization, such as function argument deserialization, function result serialization, logging, etc., of the service.</param>
     /// <returns>The updated kernel builder.</returns>
     public static IKernelBuilder AddOnnxRuntimeGenAIChatCompletion(
         this IKernelBuilder builder,
         string modelId,
         string modelPath,
-        string? serviceId = null)
+        string? serviceId = null,
+        JsonSerializerOptions? jsonSerializerOptions = null)
     {
         builder.Services.AddKeyedSingleton<IChatCompletionService>(serviceId, (serviceProvider, _) =>
             new OnnxRuntimeGenAIChatCompletionService(
                 modelId,
                 modelPath: modelPath,
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                jsonSerializerOptions));
 
         return builder;
     }

dotnet/src/Connectors/Connectors.Onnx/OnnxRuntimeGenAIChatCompletionService.cs

@@ -2,8 +2,10 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Text;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
@@ -20,6 +22,7 @@ public sealed class OnnxRuntimeGenAIChatCompletionService : IChatCompletionServi
 {
     private readonly string _modelId;
     private readonly string _modelPath;
+    private readonly JsonSerializerOptions? _jsonSerializerOptions;
     private Model? _model;
     private Tokenizer? _tokenizer;
 
@@ -31,17 +34,19 @@ public sealed class OnnxRuntimeGenAIChatCompletionService : IChatCompletionServi
     /// <param name="modelId">The name of the model.</param>
     /// <param name="modelPath">The generative AI ONNX model path for the chat completion service.</param>
     /// <param name="loggerFactory">Optional logger factory to be used for logging.</param>
+    /// <param name="jsonSerializerOptions">The <see cref="JsonSerializerOptions"/> to use for various aspects of serialization and deserialization required by the service.</param>
     public OnnxRuntimeGenAIChatCompletionService(
         string modelId,
         string modelPath,
-        ILoggerFactory? loggerFactory = null)
+        ILoggerFactory? loggerFactory = null,
+        JsonSerializerOptions? jsonSerializerOptions = null)
     {
         Verify.NotNullOrWhiteSpace(modelId);
         Verify.NotNullOrWhiteSpace(modelPath);
 
         this._modelId = modelId;
         this._modelPath = modelPath;
-
+        this._jsonSerializerOptions = jsonSerializerOptions;
         this.AttributesInternal.Add(AIServiceExtensions.ModelIdKey, this._modelId);
     }
 
@@ -82,7 +87,7 @@ public async IAsyncEnumerable<StreamingChatMessageContent> GetStreamingChatMessa
 
     private async IAsyncEnumerable<string> RunInferenceAsync(ChatHistory chatHistory, PromptExecutionSettings? executionSettings, [EnumeratorCancellation] CancellationToken cancellationToken)
     {
-        OnnxRuntimeGenAIPromptExecutionSettings onnxPromptExecutionSettings = OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings(executionSettings);
+        OnnxRuntimeGenAIPromptExecutionSettings onnxPromptExecutionSettings = this.GetOnnxPromptExecutionSettingsSettings(executionSettings);
 
         var prompt = this.GetPrompt(chatHistory, onnxPromptExecutionSettings);
         var tokens = this.GetTokenizer().Encode(prompt);
@@ -190,6 +195,18 @@ private void UpdateGeneratorParamsFromPromptExecutionSettings(GeneratorParams ge
         }
     }
 
+    [UnconditionalSuppressMessage("Trimming", "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code", Justification = "JSOs are required only in cases where the supplied settings are not Onnx-specific. For these cases, JSOs can be provided via the class constructor.")]
+    [UnconditionalSuppressMessage("AOT", "IL3050:Calling members annotated with 'RequiresDynamicCodeAttribute' may break functionality when AOT compiling.", Justification = "JSOs are required only in cases where the supplied settings are not Onnx-specific. For these cases, JSOs can be provided via class constructor.")]
+    private OnnxRuntimeGenAIPromptExecutionSettings GetOnnxPromptExecutionSettingsSettings(PromptExecutionSettings? executionSettings)
+    {
+        if (this._jsonSerializerOptions is not null)
+        {
+            return OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings(executionSettings, this._jsonSerializerOptions);
+        }
+
+        return OnnxRuntimeGenAIPromptExecutionSettings.FromExecutionSettings(executionSettings);
+    }
+
     /// <inheritdoc/>
     public void Dispose()
     {

dotnet/src/Connectors/Connectors.Onnx/OnnxRuntimeGenAIPromptExecutionSettings.cs

@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
 using Microsoft.SemanticKernel.Text;
 
 namespace Microsoft.SemanticKernel.Connectors.Onnx;
@@ -14,8 +16,10 @@ public sealed class OnnxRuntimeGenAIPromptExecutionSettings : PromptExecutionSet
     /// <summary>
     /// Convert PromptExecutionSettings to OnnxRuntimeGenAIPromptExecutionSettings
     /// </summary>
-    /// <param name="executionSettings"></param>
-    /// <returns></returns>
+    /// <param name="executionSettings">The <see cref="PromptExecutionSettings"/> to convert to <see cref="OnnxRuntimeGenAIPromptExecutionSettings"/>.</param>
+    /// <returns>Returns the <see cref="OnnxRuntimeGenAIPromptExecutionSettings"/> object.</returns>
+    [RequiresUnreferencedCode("This method uses reflection to serialize and deserialize the execution settings, making it incompatible with AOT scenarios.")]
+    [RequiresDynamicCode("This method uses reflection to serialize and deserialize the execution settings, making it incompatible with AOT scenarios.")]
     public static OnnxRuntimeGenAIPromptExecutionSettings FromExecutionSettings(PromptExecutionSettings? executionSettings)
     {
         if (executionSettings is null)
@@ -28,10 +32,34 @@ public static OnnxRuntimeGenAIPromptExecutionSettings FromExecutionSettings(Prom
             return settings;
         }
 
-        var json = JsonSerializer.Serialize(executionSettings);
+        var json = JsonSerializer.Serialize<object>(executionSettings);
 
-        var onnxRuntimeGenAIPromptExecutionSettings = JsonSerializer.Deserialize<OnnxRuntimeGenAIPromptExecutionSettings>(json, JsonOptionsCache.ReadPermissive);
-        return onnxRuntimeGenAIPromptExecutionSettings!;
+        return JsonSerializer.Deserialize<OnnxRuntimeGenAIPromptExecutionSettings>(json, JsonOptionsCache.ReadPermissive)!;
+    }
+
+    /// <summary>
+    /// Convert PromptExecutionSettings to OnnxRuntimeGenAIPromptExecutionSettings
+    /// </summary>
+    /// <param name="executionSettings">The <see cref="PromptExecutionSettings"/> to convert to <see cref="OnnxRuntimeGenAIPromptExecutionSettings"/>.</param>
+    /// <param name="jsonSerializerOptions">The <see cref="JsonSerializerOptions"/> to use for serialization of <see cref="PromptExecutionSettings"/> and deserialize them to <see cref="OnnxRuntimeGenAIPromptExecutionSettings"/>.</param>
+    /// <returns>Returns the <see cref="OnnxRuntimeGenAIPromptExecutionSettings"/> object.</returns>
+    public static OnnxRuntimeGenAIPromptExecutionSettings FromExecutionSettings(PromptExecutionSettings? executionSettings, JsonSerializerOptions jsonSerializerOptions)
+    {
+        if (executionSettings is null)
+        {
+            return new OnnxRuntimeGenAIPromptExecutionSettings();
+        }
+
+        if (executionSettings is OnnxRuntimeGenAIPromptExecutionSettings settings)
+        {
+            return settings;
+        }
+
+        JsonTypeInfo typeInfo = jsonSerializerOptions.GetTypeInfo(executionSettings!.GetType());
+
+        var json = JsonSerializer.Serialize(executionSettings, typeInfo);
+
+        return JsonSerializer.Deserialize<OnnxRuntimeGenAIPromptExecutionSettings>(json, OnnxRuntimeGenAIPromptExecutionSettingsJsonSerializerContext.ReadPermissive.OnnxRuntimeGenAIPromptExecutionSettings)!;
     }
 
     /// <summary>

dotnet/src/Connectors/Connectors.Onnx/OnnxServiceCollectionExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System.IO;
+using System.Text.Json;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.SemanticKernel.ChatCompletion;
@@ -23,18 +24,21 @@ public static class OnnxServiceCollectionExtensions
     /// <param name="modelId">The name of the model.</param>
     /// <param name="modelPath">The generative AI ONNX model path.</param>
     /// <param name="serviceId">Optional service ID.</param>
+    /// <param name="jsonSerializerOptions">The <see cref="JsonSerializerOptions"/> to use for various aspects of serialization and deserialization required by the service.</param>
     /// <returns>The updated service collection.</returns>
     public static IServiceCollection AddOnnxRuntimeGenAIChatCompletion(
         this IServiceCollection services,
         string modelId,
         string modelPath,
-        string? serviceId = null)
+        string? serviceId = null,
+        JsonSerializerOptions? jsonSerializerOptions = null)
     {
         services.AddKeyedSingleton<IChatCompletionService>(serviceId, (serviceProvider, _) =>
             new OnnxRuntimeGenAIChatCompletionService(
                 modelId,
                 modelPath,
-                loggerFactory: serviceProvider.GetService<ILoggerFactory>()));
+                loggerFactory: serviceProvider.GetService<ILoggerFactory>(),
+                jsonSerializerOptions));
 
         return services;
     }

dotnet/src/Connectors/Connectors.Onnx/Text/OnnxRuntimeGenAIPromptExecutionSettingsJsonSerializerContext.cs

@@ -0,0 +1,18 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Microsoft.SemanticKernel.Connectors.Onnx;
+
+namespace Microsoft.SemanticKernel.Text;
+
+[JsonSerializable(typeof(OnnxRuntimeGenAIPromptExecutionSettings))]
+internal sealed partial class OnnxRuntimeGenAIPromptExecutionSettingsJsonSerializerContext : JsonSerializerContext
+{
+    public static readonly OnnxRuntimeGenAIPromptExecutionSettingsJsonSerializerContext ReadPermissive = new(new()
+    {
+        AllowTrailingCommas = true,
+        PropertyNameCaseInsensitive = true,
+        ReadCommentHandling = JsonCommentHandling.Skip,
+    });
+}

dotnet/src/Functions/Functions.Yaml/PromptExecutionSettingsTypeConverter.cs

@@ -9,6 +9,7 @@
 using YamlDotNet.Serialization;
 using YamlDotNet.Serialization.BufferedDeserialization;
 using YamlDotNet.Serialization.NamingConventions;
+using YamlDotNet.Serialization.ObjectFactories;
 
 namespace Microsoft.SemanticKernel;
 
@@ -29,6 +30,7 @@ public bool Accepts(Type type)
         s_deserializer ??= new DeserializerBuilder()
             .WithNamingConvention(UnderscoredNamingConvention.Instance)
             .IgnoreUnmatchedProperties() // Required to ignore the 'type' property used as type discrimination. Otherwise, the "Property 'type' not found on type '{type.FullName}'" exception is thrown.
+            .WithObjectFactory(new FunctionChoiceBehaviorsObjectFactory())
             .WithTypeDiscriminatingNodeDeserializer(CreateAndRegisterTypeDiscriminatingNodeDeserializer)
             .Build();
 
@@ -98,4 +100,22 @@ private static void CreateAndRegisterTypeDiscriminatingNodeDeserializer(ITypeDis
     /// The YamlDotNet deserializer instance.
     /// </summary>
     private static IDeserializer? s_deserializer;
+
+    private sealed class FunctionChoiceBehaviorsObjectFactory : ObjectFactoryBase
+    {
+        private static DefaultObjectFactory? s_defaultFactory = null;
+
+        public override object Create(Type type)
+        {
+            if (type == typeof(AutoFunctionChoiceBehavior) ||
+                type == typeof(NoneFunctionChoiceBehavior) ||
+                type == typeof(RequiredFunctionChoiceBehavior))
+            {
+                return Activator.CreateInstance(type, nonPublic: true)!;
+            }
+
+            // Use the default object factory for other types
+            return (s_defaultFactory ??= new DefaultObjectFactory()).Create(type);
+        }
+    }
 }

dotnet/src/IntegrationTests/Processes/ProcessCycleTests.cs

@@ -1,12 +1,12 @@
 // Copyright (c) Microsoft. All rights reserved.
 
-using Microsoft.SemanticKernel;
-using System.Threading.Tasks;
 using System;
+using System.Threading.Tasks;
 using Microsoft.Extensions.Configuration;
+using Microsoft.SemanticKernel;
+using SemanticKernel.IntegrationTests.Agents;
 using SemanticKernel.IntegrationTests.TestSettings;
 using Xunit;
-using SemanticKernel.IntegrationTests.Agents;
 
 namespace SemanticKernel.IntegrationTests.Processes;