Support JsonExtensionData in src-gen fast-path

src/libraries/System.Text.Json/gen/JsonConstants.cs

@@ -11,5 +11,7 @@ internal static partial class JsonConstants
 
  public const string IJsonOnSerializedFullName = "System.Text.Json.Serialization.IJsonOnSerialized";
  public const string IJsonOnSerializingFullName = "System.Text.Json.Serialization.IJsonOnSerializing";
+
+ public const string JsonSerializableAttributeFullName = "System.Text.Json.Serialization.JsonSerializableAttribute";
  }
 }

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

@@ -47,17 +47,20 @@ private sealed partial class Emitter
  // global::fully.qualified.name for referenced types
  private const string ArrayTypeRef = "global::System.Array";
  private const string InvalidOperationExceptionTypeRef = "global::System.InvalidOperationException";
+ private const string StringTypeRef = "global::System.String";
  private const string TypeTypeRef = "global::System.Type";
  private const string UnsafeTypeRef = "global::System.Runtime.CompilerServices.Unsafe";
  private const string EqualityComparerTypeRef = "global::System.Collections.Generic.EqualityComparer";
+ private const string IDictionaryTypeRef = "global::System.Collections.Generic.IDictionary";
  private const string IListTypeRef = "global::System.Collections.Generic.IList";
  private const string KeyValuePairTypeRef = "global::System.Collections.Generic.KeyValuePair";
  private const string JsonEncodedTextTypeRef = "global::System.Text.Json.JsonEncodedText";
  private const string JsonNamingPolicyTypeRef = "global::System.Text.Json.JsonNamingPolicy";
  private const string JsonSerializerTypeRef = "global::System.Text.Json.JsonSerializer";
  private const string JsonSerializerOptionsTypeRef = "global::System.Text.Json.JsonSerializerOptions";
- private const string JsonSerializerContextTypeRef = "global::System.Text.Json.Serialization.JsonSerializerContext";
+ private const string JsonNodeTypeRef = "global::System.Text.Json.Nodes.JsonNode";
  private const string Utf8JsonWriterTypeRef = "global::System.Text.Json.Utf8JsonWriter";
+ private const string JsonSerializerContextTypeRef = "global::System.Text.Json.Serialization.JsonSerializerContext";
  private const string JsonConverterTypeRef = "global::System.Text.Json.Serialization.JsonConverter";
  private const string JsonConverterFactoryTypeRef = "global::System.Text.Json.Serialization.JsonConverterFactory";
  private const string JsonCollectionInfoValuesTypeRef = "global::System.Text.Json.Serialization.Metadata.JsonCollectionInfoValues";
@@ -268,10 +271,16 @@ private void GenerateTypeInfo(TypeGenerationSpec typeGenerationSpec)
  }
  }
 
- TypeGenerationSpec? extPropTypeSpec = typeGenerationSpec.ExtensionDataPropertyTypeSpec;
+ TypeGenerationSpec? extPropTypeSpec = typeGenerationSpec.ExtensionDataPropertySpec?.TypeGenerationSpec;
  if (extPropTypeSpec != null)
  {
  GenerateTypeInfo(extPropTypeSpec);
+
+ if (extPropTypeSpec.Type == _generationSpec.JsonObjectType)
+ {
+ GenerateTypeInfo(extPropTypeSpec.CollectionKeyTypeMetadata);
+ GenerateTypeInfo(extPropTypeSpec.CollectionValueTypeMetadata);
+ }
  }
  }
  break;
@@ -541,6 +550,17 @@ private string GenerateFastPathFuncForEnumerable(TypeGenerationSpec typeGenerati
  }
 
  private string GenerateFastPathFuncForDictionary(TypeGenerationSpec typeGenerationSpec)
+ {
+ string serializationLogic = $@"{WriterVarName}.WriteStartObject();
+
+{IndentSource(GenerateFastPathForDictionaryKeyValuePairs(typeGenerationSpec, ValueVarName), numIndentations: 1)}
+
+ {WriterVarName}.WriteEndObject();";
+
+ return GenerateFastPathFuncForType(typeGenerationSpec, serializationLogic, emitNullCheck: typeGenerationSpec.CanBeNull);
+ }
+
+ private string GenerateFastPathForDictionaryKeyValuePairs(TypeGenerationSpec typeGenerationSpec, string dictionaryValueVarName)
  {
  TypeGenerationSpec keyTypeGenerationSpec = typeGenerationSpec.CollectionKeyTypeMetadata;
  TypeGenerationSpec valueTypeGenerationSpec = typeGenerationSpec.CollectionValueTypeMetadata;
@@ -568,16 +588,7 @@ private string GenerateFastPathFuncForDictionary(TypeGenerationSpec typeGenerati
  {GetSerializeLogicForNonPrimitiveType(valueTypeGenerationSpec, valueToWrite)}";
  }
 
- string serializationLogic = $@"{WriterVarName}.WriteStartObject();
-
- foreach ({KeyValuePairTypeRef}<{keyTypeGenerationSpec.TypeRef}, {valueTypeGenerationSpec.TypeRef}> {pairVarName} in {ValueVarName})
- {{
- {elementSerializationLogic}
- }}
-
- {WriterVarName}.WriteEndObject();";
-
- return GenerateFastPathFuncForType(typeGenerationSpec, serializationLogic, emitNullCheck: typeGenerationSpec.CanBeNull);
+ return $"foreach ({KeyValuePairTypeRef}<{keyTypeGenerationSpec.TypeRef}, {valueTypeGenerationSpec.TypeRef}> {pairVarName} in {dictionaryValueVarName})\r\n {{\r\n {elementSerializationLogic}\r\n }}";
  }
 
  private string GenerateForObject(TypeGenerationSpec typeMetadata)
@@ -832,7 +843,7 @@ private string GenerateFastPathFuncForObject(TypeGenerationSpec typeGenSpec)
 
  foreach (PropertyGenerationSpec propertyGenSpec in serializableProperties.Values)
  {
- if (!ShouldIncludePropertyForFastPath(propertyGenSpec, options))
+ if (propertyGenSpec.IsExtensionData || !ShouldIncludePropertyForFastPath(propertyGenSpec, options))
  {
  continue;
  }
@@ -892,6 +903,34 @@ private string GenerateFastPathFuncForObject(TypeGenerationSpec typeGenSpec)
  sb.Append(WrapSerializationLogicInDefaultCheckIfRequired(serializationLogic, propValue, propertyTypeSpec.TypeRef, defaultCheckType));
  }
 
+ PropertyGenerationSpec? extDataPropSpec = typeGenSpec.ExtensionDataPropertySpec;
+ if (extDataPropSpec != null)
+ {
+ TypeGenerationSpec extDataPropTypeSpec = extDataPropSpec.TypeGenerationSpec;
+ string dictionaryValue = $"{ValueVarName}.{extDataPropSpec.ClrName}";
+
+ ClassType classType = extDataPropTypeSpec.ClassType;
+
+ if (_currentContext.ContextTypeRef.Contains("Extension"))
+ {
+ }
+
+ if (classType != ClassType.Dictionary)
+ {
+ Debug.Assert(extDataPropTypeSpec.Type == _generationSpec.JsonObjectType);
+ dictionaryValue = $"({IDictionaryTypeRef}<{StringTypeRef}, {JsonNodeTypeRef}>){dictionaryValue}";
+ }
+
+ sb.Append($@"
+
+ // Writing extension data members
+ if ({dictionaryValue} != null)
+ {{
+ {GenerateFastPathForDictionaryKeyValuePairs(extDataPropSpec.TypeGenerationSpec, dictionaryValue)}
+ }}
+");
+ }
+
  // End method logic.
  sb.Append($@"
 

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

@@ -44,8 +44,6 @@ private sealed class Parser
  private const string JsonSerializerContextFullName = "System.Text.Json.Serialization.JsonSerializerContext";
  private const string JsonSourceGenerationOptionsAttributeFullName = "System.Text.Json.Serialization.JsonSourceGenerationOptionsAttribute";
 
- internal const string JsonSerializableAttributeFullName = "System.Text.Json.Serialization.JsonSerializableAttribute";
-
  private const string DateOnlyFullName = "System.DateOnly";
  private const string TimeOnlyFullName = "System.TimeOnly";
  private const string IAsyncEnumerableFullName = "System.Collections.Generic.IAsyncEnumerable`1";
@@ -251,7 +249,7 @@ public Parser(Compilation compilation, in JsonSourceGenerationContext sourceGene
  {
  Compilation compilation = _compilation;
  INamedTypeSymbol jsonSerializerContextSymbol = compilation.GetBestTypeByMetadataName(JsonSerializerContextFullName);
- INamedTypeSymbol jsonSerializableAttributeSymbol = compilation.GetBestTypeByMetadataName(JsonSerializableAttributeFullName);
+ INamedTypeSymbol jsonSerializableAttributeSymbol = compilation.GetBestTypeByMetadataName(JsonConstants.JsonSerializableAttributeFullName);
  INamedTypeSymbol jsonSourceGenerationOptionsAttributeSymbol = compilation.GetBestTypeByMetadataName(JsonSourceGenerationOptionsAttributeFullName);
  INamedTypeSymbol jsonConverterOfTAttributeSymbol = compilation.GetBestTypeByMetadataName(JsonConverterOfTFullName);
 
@@ -392,6 +390,7 @@ public Parser(Compilation compilation, in JsonSourceGenerationContext sourceGene
  BooleanType = _booleanType,
  ByteArrayType = _byteArrayType,
  CharType = _charType,
+ JsonObjectType = _jsonObjectType,
  DateTimeType = _dateTimeType,
  DateTimeOffsetType = _dateTimeOffsetType,
  GuidType = _guidType,
@@ -705,7 +704,7 @@ private TypeGenerationSpec GetOrAddTypeGenerationSpec(Type type, JsonSourceGener
  TypeGenerationSpec? collectionKeyTypeSpec = null;
  TypeGenerationSpec? collectionValueTypeSpec = null;
  TypeGenerationSpec? nullableUnderlyingTypeGenSpec = null;
- TypeGenerationSpec? dataExtensionPropGenSpec = null;
+ PropertyGenerationSpec? dataExtPropGenSpec = null;
  string? runtimeTypeRef = null;
  List<PropertyGenerationSpec>? propGenSpecList = null;
  ObjectConstructionStrategy constructionStrategy = default;
@@ -761,6 +760,13 @@ private TypeGenerationSpec GetOrAddTypeGenerationSpec(Type type, JsonSourceGener
  }
  }
 
+ // Populate info required to support JsonObject as extension data in fast-path.
+ if (type == _jsonObjectType)
+ {
+ collectionKeyTypeSpec = GetOrAddTypeGenerationSpec(_stringType, generationMode);
+ collectionValueTypeSpec = GetOrAddTypeGenerationSpec(_jsonNodeType, generationMode);
+ }
+
  if (foundDesignTimeCustomConverter)
  {
  classType = converterInstatiationLogic != null
@@ -1029,6 +1035,7 @@ private TypeGenerationSpec GetOrAddTypeGenerationSpec(Type type, JsonSourceGener
  for (Type? currentType = type; currentType != null; currentType = currentType.BaseType)
  {
  PropertyGenerationSpec spec;
+ bool seenExtDataAttr = false;
 
  foreach (PropertyInfo propertyInfo in currentType.GetProperties(bindingFlags))
  {
@@ -1077,19 +1084,25 @@ void CacheMemberHelper(Location memberLocation)
 
  if (spec.IsExtensionData)
  {
- if (dataExtensionPropGenSpec != null)
+ if (seenExtDataAttr)
  {
  _typeLevelDiagnostics.Add((type, MultipleJsonExtensionDataAttribute, new string[] { type.Name }));
  }
-
- Type propType = spec.TypeGenerationSpec.Type;
- if (!IsValidDataExtensionPropertyType(propType))
+ else
  {
- _sourceGenerationContext.ReportDiagnostic(Diagnostic.Create(DataExtensionPropertyInvalid, memberLocation, new string[] { type.Name, spec.ClrName }));
+ seenExtDataAttr = true;
+ Type propType = spec.TypeGenerationSpec.Type;
+
+ if (!IsValidDataExtensionPropertyType(propType))
+ {
+ _sourceGenerationContext.ReportDiagnostic(Diagnostic.Create(DataExtensionPropertyInvalid, memberLocation, new string[] { type.Name, spec.ClrName }));
+ }
+ else
+ {
+ dataExtPropGenSpec = spec;
+ _implicitlyRegisteredTypes.Add(GetOrAddTypeGenerationSpec(propType, generationMode));
+ }
  }
-
- dataExtensionPropGenSpec = GetOrAddTypeGenerationSpec(propType, generationMode);
- _implicitlyRegisteredTypes.Add(dataExtensionPropGenSpec);
  }
 
  if (!hasInitOnlyProperties && spec.CanUseSetter && spec.IsInitOnlySetter && !PropertyIsConstructorParameter(spec, paramGenSpecArray))
@@ -1125,7 +1138,7 @@ void CacheMemberHelper(Location memberLocation)
  constructionStrategy,
  nullableUnderlyingTypeMetadata: nullableUnderlyingTypeGenSpec,
  runtimeTypeRef,
- dataExtensionPropGenSpec,
+ dataExtPropGenSpec,
  converterInstatiationLogic,
  implementsIJsonOnSerialized : implementsIJsonOnSerialized,
  implementsIJsonOnSerializing : implementsIJsonOnSerializing,

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Roslyn3.11.cs

@@ -3,11 +3,7 @@
 
 //#define LAUNCH_DEBUGGER
 using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Linq;
-using System.Reflection;
-using System.Text.Json.Reflection;
 using System.Threading;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -109,7 +105,7 @@ public void OnVisitSyntaxNode(GeneratorSyntaxContext context)
  INamedTypeSymbol attributeContainingTypeSymbol = attributeSymbol.ContainingType;
  string fullName = attributeContainingTypeSymbol.ToDisplayString();
 
- if (fullName == Parser.JsonSerializableAttributeFullName)
+ if (fullName == JsonConstants.JsonSerializableAttributeFullName)
  {
  return classDeclarationSyntax;
  }

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Roslyn4.0.cs

@@ -4,13 +4,8 @@
 //#define LAUNCH_DEBUGGER
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Linq;
-using System.Reflection;
-using System.Text.Json.Reflection;
-using System.Threading;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Text;
 #if !ROSLYN4_4_OR_GREATER
@@ -32,7 +27,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
 #if !ROSLYN4_4_OR_GREATER
  context,
 #endif
- Parser.JsonSerializableAttributeFullName,
+ JsonConstants.JsonSerializableAttributeFullName,
  (node, _) => node is ClassDeclarationSyntax,
  (context, _) => (ClassDeclarationSyntax)context.TargetNode);
 
@@ -42,7 +37,9 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
  context.RegisterSourceOutput(compilationAndClasses, (spc, source) => Execute(source.Item1, source.Item2, spc));
  }
 
+#pragma warning disable CA1822 // Mark members as static
  private void Execute(Compilation compilation, ImmutableArray<ClassDeclarationSyntax> contextClasses, SourceProductionContext sourceProductionContext)
+#pragma warning restore CA1822 // Mark members as static
  {
 #if LAUNCH_DEBUGGER
  if (!Diagnostics.Debugger.IsAttached)

src/libraries/System.Text.Json/gen/SourceGenerationSpec.cs

@@ -1,11 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Text.Json.Reflection;
-using Microsoft.CodeAnalysis;
 
 namespace System.Text.Json.SourceGeneration
 {
@@ -19,6 +16,7 @@ internal sealed class SourceGenerationSpec
  public Type BooleanType { get; init; }
  public Type ByteArrayType { get; init; }
  public Type CharType { get; init; }
+ public Type JsonObjectType { get; init; }
  public Type DateTimeType { private get; init; }
  public Type DateTimeOffsetType { private get; init; }
  public Type GuidType { private get; init; }

src/libraries/System.Text.Json/gen/TypeGenerationSpec.cs

@@ -76,7 +76,7 @@ internal sealed class TypeGenerationSpec
  /// </summary>
  public string? RuntimeTypeRef { get; private set; }
 
- public TypeGenerationSpec? ExtensionDataPropertyTypeSpec { get; private set; }
+ public PropertyGenerationSpec? ExtensionDataPropertySpec { get; private set; }
 
  public string? ConverterInstantiationLogic { get; private set; }
 
@@ -126,7 +126,7 @@ public void Initialize(
  ObjectConstructionStrategy constructionStrategy,
  TypeGenerationSpec? nullableUnderlyingTypeMetadata,
  string? runtimeTypeRef,
- TypeGenerationSpec? extensionDataPropertyTypeSpec,
+ PropertyGenerationSpec? extDataPropSpec,
  string? converterInstantiationLogic,
  bool implementsIJsonOnSerialized,
  bool implementsIJsonOnSerializing,
@@ -152,7 +152,7 @@ public void Initialize(
  ConstructionStrategy = constructionStrategy;
  NullableUnderlyingTypeMetadata = nullableUnderlyingTypeMetadata;
  RuntimeTypeRef = runtimeTypeRef;
- ExtensionDataPropertyTypeSpec = extensionDataPropertyTypeSpec;
+ ExtensionDataPropertySpec = extDataPropSpec;
  ConverterInstantiationLogic = converterInstantiationLogic;
  ImplementsIJsonOnSerialized = implementsIJsonOnSerialized;
  ImplementsIJsonOnSerializing = implementsIJsonOnSerializing;
@@ -253,11 +253,6 @@ private bool FastPathIsSupported()
 
  if (ClassType == ClassType.Object)
  {
- if (ExtensionDataPropertyTypeSpec != null)
- {
- return false;
- }
-
  foreach (PropertyGenerationSpec property in PropertyGenSpecList)
  {
  if (property.TypeGenerationSpec.Type.IsObjectType() ||