using System.Diagnostics.CodeAnalysis; using System.Reflection; using System.Text.Json.Reflection; namespace System.Text.Json.Serialization.Converters { [RequiresDynamicCode("JSON serialization and deserialization might require types that cannot be statically analyzed and might need runtime code generation. Use System.Text.Json source generation for native AOT applications.")] internal sealed class NullableConverterFactory : JsonConverterFactory { public override bool CanConvert(Type typeToConvert) { return typeToConvert.IsNullableOfT(); } public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options) { Type type = typeToConvert.GetGenericArguments()[0]; JsonConverter converterInternal = options.GetConverterInternal(type); if (!converterInternal.Type.IsValueType && type.IsValueType) return converterInternal; return CreateValueConverter(type, converterInternal); } public static JsonConverter CreateValueConverter(Type valueTypeToConvert, JsonConverter valueConverter) { return (JsonConverter)Activator.CreateInstance(GetNullableConverterType(valueTypeToConvert), BindingFlags.Instance | BindingFlags.Public, null, new object[1] { valueConverter }, null); } [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2071:UnrecognizedReflectionPattern", Justification = "'NullableConverter<T> where T : struct' implies 'T : new()', so the trimmer is warning calling MakeGenericType here because valueTypeToConvert's constructors are not annotated. But NullableConverter doesn't call new T(), so this is safe.")] [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2070:UnrecognizedReflectionPattern", Justification = "'NullableConverter<T> where T : struct' implies 'T : new()', so the trimmer is warning calling MakeGenericType here because valueTypeToConvert's constructors are not annotated. But NullableConverter doesn't call new T(), so this is safe.")] [return: DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] private static Type GetNullableConverterType(Type valueTypeToConvert) { return typeof(NullableConverter<>).MakeGenericType(valueTypeToConvert); } } }