Add ReferenceHandler to JsonSourceGenerationOptions

src/libraries/System.Text.Json/Common/JsonKnownReferenceHandler.cs

@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Text.Json.Serialization
+{
+    /// <summary>
+    /// The <see cref="ReferenceHandler"/> to be used at run time.
+    /// </summary>
+    public enum JsonKnownReferenceHandler
+    {
+        /// <summary>
+        /// Specifies that circular references should throw exceptions.
+        /// </summary>
+        Unspecified = 0,
+
+        /// <summary>
+        /// Specifies that the built-in <see cref="ReferenceHandler.Preserve"/> be used to handle references.
+        /// </summary>
+        Preserve = 1,
+
+        /// <summary>
+        /// Specifies that the built-in <see cref="ReferenceHandler.IgnoreCycles"/> be used to ignore cyclic references.
+        /// </summary>
+        IgnoreCycles = 2,
+    }
+}

src/libraries/System.Text.Json/Common/JsonSourceGenerationOptionsAttribute.cs

@@ -115,6 +115,11 @@ public JsonSourceGenerationOptionsAttribute(JsonSerializerDefaults defaults)
         /// </summary>
         public JsonCommentHandling ReadCommentHandling { get; set; }
 
+        /// <summary>
+        /// Specifies the default value of <see cref="JsonSerializerOptions.ReferenceHandler"/> when set.
+        /// </summary>
+        public JsonKnownReferenceHandler ReferenceHandler { get; set; }
+
         /// <summary>
         /// Specifies the default value of <see cref="JsonSerializerOptions.RespectNullableAnnotations"/> when set.
         /// </summary>

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Emitter.cs

@@ -37,6 +37,8 @@ private sealed partial class Emitter
             private const string OptionsLocalVariableName = "options";
             private const string ValueVarName = "value";
             private const string WriterVarName = "writer";
+            private const string PreserveReferenceHandlerPropertyName = "Preserve";
+            private const string IgnoreCyclesReferenceHandlerPropertyName = "IgnoreCycles";
 
             private static readonly AssemblyName s_assemblyName = typeof(Emitter).Assembly.GetName();
 
@@ -70,6 +72,7 @@ private sealed partial class Emitter
             private const string JsonPropertyInfoValuesTypeRef = "global::System.Text.Json.Serialization.Metadata.JsonPropertyInfoValues";
             private const string JsonTypeInfoTypeRef = "global::System.Text.Json.Serialization.Metadata.JsonTypeInfo";
             private const string JsonTypeInfoResolverTypeRef = "global::System.Text.Json.Serialization.Metadata.IJsonTypeInfoResolver";
+            private const string ReferenceHandlerTypeRef = "global::System.Text.Json.Serialization.ReferenceHandler";
             private const string EmptyTypeArray = "global::System.Array.Empty<global::System.Type>()";
 
             /// <summary>
@@ -1246,6 +1249,9 @@ private static void GetLogicForDefaultSerializerOptionsInit(SourceGenerationOpti
                 if (optionsSpec.ReadCommentHandling is JsonCommentHandling readCommentHandling)
                     writer.WriteLine($"ReadCommentHandling = {FormatCommentHandling(readCommentHandling)},");
 
+                if (optionsSpec.ReferenceHandler is JsonKnownReferenceHandler referenceHandler)
+                    writer.WriteLine($"ReferenceHandler = {FormatReferenceHandler(referenceHandler)},");
+
                 if (optionsSpec.UnknownTypeHandling is JsonUnknownTypeHandling unknownTypeHandling)
                     writer.WriteLine($"UnknownTypeHandling = {FormatUnknownTypeHandling(unknownTypeHandling)},");
 
@@ -1280,6 +1286,20 @@ static string FormatNamingPolicy(JsonKnownNamingPolicy knownNamingPolicy)
                     ? $"{JsonNamingPolicyTypeRef}.{policyName}"
                     : "null";
                 }
+
+                static string FormatReferenceHandler(JsonKnownReferenceHandler referenceHandler)
+                {
+                    string? referenceHandlerName = referenceHandler switch
+                    {
+                        JsonKnownReferenceHandler.Preserve => PreserveReferenceHandlerPropertyName,
+                        JsonKnownReferenceHandler.IgnoreCycles => IgnoreCyclesReferenceHandlerPropertyName,
+                        _ => null,
+                    };
+
+                    return referenceHandlerName != null
+                    ? $"{ReferenceHandlerTypeRef}.{referenceHandlerName}"
+                    : "null";
+                }
             }
 
             private static void GenerateConverterHelpers(SourceWriter writer, bool emitGetConverterForNullablePropertyMethod)

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Parser.cs

@@ -280,6 +280,7 @@ private SourceGenerationOptionsSpec ParseJsonSourceGenerationOptionsAttribute(IN
                 bool? propertyNameCaseInsensitive = null;
                 JsonKnownNamingPolicy? propertyNamingPolicy = null;
                 JsonCommentHandling? readCommentHandling = null;
+                JsonKnownReferenceHandler? referenceHandler = null;
                 JsonUnknownTypeHandling? unknownTypeHandling = null;
                 JsonUnmappedMemberHandling? unmappedMemberHandling = null;
                 bool? useStringEnumConverter = null;
@@ -379,6 +380,10 @@ private SourceGenerationOptionsSpec ParseJsonSourceGenerationOptionsAttribute(IN
                             readCommentHandling = (JsonCommentHandling)namedArg.Value.Value!;
                             break;
 
+                        case nameof(JsonSourceGenerationOptionsAttribute.ReferenceHandler):
+                            referenceHandler = (JsonKnownReferenceHandler)namedArg.Value.Value!;
+                            break;
+
                         case nameof(JsonSourceGenerationOptionsAttribute.UnknownTypeHandling):
                             unknownTypeHandling = (JsonUnknownTypeHandling)namedArg.Value.Value!;
                             break;
@@ -434,6 +439,7 @@ private SourceGenerationOptionsSpec ParseJsonSourceGenerationOptionsAttribute(IN
                     PropertyNameCaseInsensitive = propertyNameCaseInsensitive,
                     PropertyNamingPolicy = propertyNamingPolicy,
                     ReadCommentHandling = readCommentHandling,
+                    ReferenceHandler = referenceHandler,
                     UnknownTypeHandling = unknownTypeHandling,
                     UnmappedMemberHandling = unmappedMemberHandling,
                     UseStringEnumConverter = useStringEnumConverter,

src/libraries/System.Text.Json/gen/Model/SourceGenerationOptionsSpec.cs

@@ -52,6 +52,8 @@ public sealed record SourceGenerationOptionsSpec
 
         public required JsonCommentHandling? ReadCommentHandling { get; init; }
 
+        public required JsonKnownReferenceHandler? ReferenceHandler { get; init; }
+
         public required JsonUnknownTypeHandling? UnknownTypeHandling { get; init; }
 
         public required JsonUnmappedMemberHandling? UnmappedMemberHandling { get; init; }

src/libraries/System.Text.Json/gen/System.Text.Json.SourceGeneration.targets

@@ -46,6 +46,7 @@
     <Compile Include="..\Common\JsonKebabCaseLowerNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKebabCaseLowerNamingPolicy.cs" />
     <Compile Include="..\Common\JsonKebabCaseUpperNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKebabCaseUpperNamingPolicy.cs" />
     <Compile Include="..\Common\JsonKnownNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKnownNamingPolicy.cs" />
+    <Compile Include="..\Common\JsonKnownReferenceHandler.cs" Link="Common\System\Text\Json\Serialization\JsonKnownReferenceHandler.cs" />
     <Compile Include="..\Common\JsonNumberHandling.cs" Link="Common\System\Text\Json\Serialization\JsonNumberHandling.cs" />
     <Compile Include="..\Common\JsonObjectCreationHandling.cs" Link="Common\System\Text\Json\Serialization\JsonObjectCreationHandling.cs" />
     <Compile Include="..\Common\JsonSeparatorNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonSeparatorNamingPolicy.cs" />

src/libraries/System.Text.Json/ref/System.Text.Json.cs

@@ -1043,6 +1043,12 @@ public enum JsonKnownNamingPolicy
         KebabCaseLower = 4,
         KebabCaseUpper = 5,
     }
+    public enum JsonKnownReferenceHandler
+    {
+        Unspecified = 0,
+        Preserve = 1,
+        IgnoreCycles = 2,
+    }
     public sealed partial class JsonNumberEnumConverter<TEnum> : System.Text.Json.Serialization.JsonConverterFactory where TEnum : struct, System.Enum
     {
         public JsonNumberEnumConverter() { }
@@ -1143,6 +1149,7 @@ public JsonSourceGenerationOptionsAttribute(System.Text.Json.JsonSerializerDefau
         public bool PropertyNameCaseInsensitive { get { throw null; } set { } }
         public System.Text.Json.Serialization.JsonKnownNamingPolicy PropertyNamingPolicy { get { throw null; } set { } }
         public System.Text.Json.JsonCommentHandling ReadCommentHandling { get { throw null; } set { } }
+        public System.Text.Json.Serialization.JsonKnownReferenceHandler ReferenceHandler { get { throw null; } set { } }
         public bool RespectNullableAnnotations { get { throw null; } set { } }
         public bool RespectRequiredConstructorParameters { get { throw null; } set { } }
         public System.Text.Json.Serialization.JsonUnknownTypeHandling UnknownTypeHandling { get { throw null; } set { } }

src/libraries/System.Text.Json/src/System.Text.Json.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetCoreAppPrevious);$(NetCoreAppMinimum);netstandard2.0;$(NetFrameworkMinimum)</TargetFrameworks>
@@ -33,9 +33,9 @@ The System.Text.Json library is built-in as part of the shared framework in .NET
     <Compile Include="..\Common\JsonKebabCaseLowerNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKebabCaseLowerNamingPolicy.cs" />
     <Compile Include="..\Common\JsonKebabCaseUpperNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKebabCaseUpperNamingPolicy.cs" />
     <Compile Include="..\Common\JsonKnownNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonKnownNamingPolicy.cs" />
+    <Compile Include="..\Common\JsonKnownReferenceHandler.cs" Link="Common\System\Text\Json\Serialization\JsonKnownReferenceHandler.cs" />
     <Compile Include="..\Common\JsonNumberHandling.cs" Link="Common\System\Text\Json\Serialization\JsonNumberHandling.cs" />
     <Compile Include="..\Common\JsonObjectCreationHandling.cs" Link="Common\System\Text\Json\Serialization\JsonObjectCreationHandling.cs" />
-    <Compile Include="..\Common\JsonUnmappedMemberHandling.cs" Link="Common\System\Text\Json\Serialization\JsonUnmappedMemberHandling.cs" />
     <Compile Include="..\Common\JsonSeparatorNamingPolicy.cs" Link="Common\System\Text\Json\Serialization\JsonSeparatorNamingPolicy.cs" />
     <Compile Include="..\Common\JsonSerializableAttribute.cs" Link="Common\System\Text\Json\Serialization\JsonSerializableAttribute.cs" />
     <Compile Include="..\Common\JsonSerializerDefaults.cs" Link="Common\System\Text\Json\Serialization\JsonSerializerDefaults.cs" />
@@ -44,6 +44,7 @@ The System.Text.Json library is built-in as part of the shared framework in .NET
     <Compile Include="..\Common\JsonSourceGenerationMode.cs" Link="Common\System\Text\Json\Serialization\JsonSourceGenerationMode.cs" />
     <Compile Include="..\Common\JsonSourceGenerationOptionsAttribute.cs" Link="Common\System\Text\Json\Serialization\JsonSourceGenerationOptionsAttribute.cs" />
     <Compile Include="..\Common\JsonUnknownTypeHandling.cs" Link="Common\System\Text\Json\Serialization\JsonUnknownTypeHandling.cs" />
+    <Compile Include="..\Common\JsonUnmappedMemberHandling.cs" Link="Common\System\Text\Json\Serialization\JsonUnmappedMemberHandling.cs" />
     <Compile Include="..\Common\ReflectionExtensions.cs" Link="Common\System\Text\Json\Serialization\ReflectionExtensions.cs" />
     <Compile Include="..\Common\ThrowHelper.cs" Link="Common\System\Text\Json\ThrowHelper.cs" />
     <Compile Include="System\Runtime\InteropServices\JsonMarshal.cs" />
@@ -295,7 +296,6 @@ The System.Text.Json library is built-in as part of the shared framework in .NET
     <Compile Include="System\Text\Json\Serialization\ReadStackFrame.cs" />
     <Compile Include="System\Text\Json\Serialization\ReferenceHandler.cs" />
     <Compile Include="System\Text\Json\Serialization\ReferenceHandlerOfT.cs" />
-    <Compile Include="System\Text\Json\Serialization\ReferenceHandlingStrategy.cs" />
     <Compile Include="System\Text\Json\Serialization\ReferenceResolver.cs" />
     <Compile Include="System\Text\Json\Serialization\StackFrameObjectState.cs" />
     <Compile Include="System\Text\Json\Serialization\StackFramePropertyState.cs" />

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Collection/JsonCollectionConverter.cs

@@ -182,7 +182,7 @@ internal override bool OnTryRead(
                     if ((state.Current.MetadataPropertyNames & MetadataPropertyName.Id) != 0)
                     {
                         Debug.Assert(state.ReferenceId != null);
-                        Debug.Assert(options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve);
+                        Debug.Assert(options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve);
                         Debug.Assert(state.Current.ReturnValue is TCollection);
                         state.ReferenceResolver.AddReference(state.ReferenceId, state.Current.ReturnValue);
                         state.ReferenceId = null;

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Collection/JsonDictionaryConverter.cs

@@ -205,7 +205,7 @@ internal sealed override bool OnTryRead(
                     if ((state.Current.MetadataPropertyNames & MetadataPropertyName.Id) != 0)
                     {
                         Debug.Assert(state.ReferenceId != null);
-                        Debug.Assert(options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve);
+                        Debug.Assert(options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve);
                         Debug.Assert(state.Current.ReturnValue is TDictionary);
                         state.ReferenceResolver.AddReference(state.ReferenceId, state.Current.ReturnValue);
                         state.ReferenceId = null;

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectConverter.cs

@@ -117,7 +117,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
                 JsonElement element = JsonElement.ParseValue(ref reader);
 
                 // Edge case where we want to lookup for a reference when parsing into typeof(object)
-                if (options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve &&
+                if (options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve &&
                     JsonSerializer.TryHandleReferenceFromJsonElement(ref reader, ref state, element, out referenceValue))
                 {
                     value = referenceValue;
@@ -134,7 +134,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
 
             JsonNode? node = JsonNodeConverter.Instance.Read(ref reader, typeToConvert, options);
 
-            if (options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve &&
+            if (options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve &&
                 JsonSerializer.TryHandleReferenceFromJsonNode(ref reader, ref state, node, out referenceValue))
             {
                 value = referenceValue;

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectDefaultConverter.cs

@@ -125,7 +125,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
                     if ((state.Current.MetadataPropertyNames & MetadataPropertyName.Id) != 0)
                     {
                         Debug.Assert(state.ReferenceId != null);
-                        Debug.Assert(options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve);
+                        Debug.Assert(options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve);
                         state.ReferenceResolver.AddReference(state.ReferenceId, obj);
                         state.ReferenceId = null;
                     }

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectWithParameterizedConstructorConverter.cs

@@ -207,7 +207,7 @@ internal sealed override bool OnTryRead(ref Utf8JsonReader reader, Type typeToCo
                 if ((state.Current.MetadataPropertyNames & MetadataPropertyName.Id) != 0)
                 {
                     Debug.Assert(state.ReferenceId != null);
-                    Debug.Assert(options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.Preserve);
+                    Debug.Assert(options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Preserve);
                     state.ReferenceResolver.AddReference(state.ReferenceId, obj);
                     state.ReferenceId = null;
                 }

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/IgnoreReferenceHandler.cs

@@ -5,7 +5,7 @@ namespace System.Text.Json.Serialization
 {
     internal sealed class IgnoreReferenceHandler : ReferenceHandler
     {
-        public IgnoreReferenceHandler() => HandlingStrategy = ReferenceHandlingStrategy.IgnoreCycles;
+        public IgnoreReferenceHandler() => HandlingStrategy = JsonKnownReferenceHandler.IgnoreCycles;
 
         public override ReferenceResolver CreateResolver() => new IgnoreReferenceResolver();
     }

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonConverter.MetadataHandling.cs

@@ -143,7 +143,7 @@ internal bool TryHandleSerializedObjectReference(Utf8JsonWriter writer, object v
 
             switch (options.ReferenceHandlingStrategy)
             {
-                case ReferenceHandlingStrategy.IgnoreCycles:
+                case JsonKnownReferenceHandler.IgnoreCycles:
                     ReferenceResolver resolver = state.ReferenceResolver;
                     if (resolver.ContainsReferenceForCycleDetection(value))
                     {
@@ -158,7 +158,7 @@ internal bool TryHandleSerializedObjectReference(Utf8JsonWriter writer, object v
                     state.Current.IsPushedReferenceForCycleDetection = state.CurrentDepth > 0;
                     break;
 
-                case ReferenceHandlingStrategy.Preserve:
+                case JsonKnownReferenceHandler.Preserve:
                     bool canHaveIdMetadata = polymorphicConverter?.CanHaveMetadata ?? CanHaveMetadata;
                     if (canHaveIdMetadata && JsonSerializer.TryGetReferenceForValue(value, ref state, writer))
                     {

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonConverterOfT.cs

@@ -382,7 +382,7 @@ value is not null &&
                     ResolvePolymorphicConverter(value, jsonTypeInfo, options, ref state) :
                     null;
 
-                if (!isContinuation && options.ReferenceHandlingStrategy != ReferenceHandlingStrategy.None &&
+                if (!isContinuation && options.ReferenceHandlingStrategy != JsonKnownReferenceHandler.Unspecified &&
                     TryHandleSerializedObjectReference(writer, value, options, polymorphicConverter, ref state))
                 {
                     // The reference handler wrote reference metadata, serialization complete.

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerContext.cs

@@ -63,7 +63,7 @@ options.Encoder is null &&
                 // Disallow custom number handling we'd need to honor when writing.
                 // AllowReadingFromString and Strict are fine since there's no action to take when writing.
                 !JsonHelpers.RequiresSpecialNumberHandlingOnWrite(options.NumberHandling) &&
-                options.ReferenceHandlingStrategy == ReferenceHandlingStrategy.None &&
+                options.ReferenceHandlingStrategy == JsonKnownReferenceHandler.Unspecified &&
 #pragma warning disable SYSLIB0020
                 !options.IgnoreNullValues && // This property is obsolete.
 #pragma warning restore SYSLIB0020

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.cs

@@ -753,7 +753,7 @@ public ReferenceHandler? ReferenceHandler
             {
                 VerifyMutable();
                 _referenceHandler = value;
-                ReferenceHandlingStrategy = value?.HandlingStrategy ?? ReferenceHandlingStrategy.None;
+                ReferenceHandlingStrategy = value?.HandlingStrategy ?? JsonKnownReferenceHandler.Unspecified;
             }
         }
 
@@ -853,7 +853,7 @@ internal bool CanUseFastPathSerializationLogic
         private bool? _canUseFastPathSerializationLogic;
 
         // The cached value used to determine if ReferenceHandler should use Preserve or IgnoreCycles semantics or None of them.
-        internal ReferenceHandlingStrategy ReferenceHandlingStrategy = ReferenceHandlingStrategy.None;
+        internal JsonKnownReferenceHandler ReferenceHandlingStrategy = JsonKnownReferenceHandler.Unspecified;
 
         /// <summary>
         /// Specifies whether the current instance has been locked for user modification.