Serializing a KeyValuePair in DCS doesn't work in a trimmed app

[eerhardt]

See the test failing here.

fail: [FAIL] DataContractJsonSerializerTests.DCJS_KeyValuePair

info: System.NullReferenceException : Object reference not set to an instance of an object.
info:    at System.Runtime.Serialization.ReflectionClassWriter.ResolveAdapterType(Object obj, ClassDataContract classContract)
info:    at System.Runtime.Serialization.ReflectionClassWriter.ReflectionWriteClass(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context, ClassDataContract classContract, XmlDictionaryString[] memberNames)
info:    at System.Runtime.Serialization.Json.ReflectionJsonFormatWriter.ReflectionWriteClass(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, ClassDataContract classContract, XmlDictionaryString[] memberNames)
info:    at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.JsonDataContract.WriteJsonValue(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteJsonValue(JsonDataContract contract, XmlWriterDelegator writer, Object graph, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType)
info:    at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.SerializeWithXsiTypeAtTopLevel(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle originalDeclaredTypeHandle, Type graphType)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalWriteObject(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.XmlObjectSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
info:    at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
info:    at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteObject(XmlDictionaryWriter writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteObject(Stream stream, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializer.WriteObject(Stream stream, Object graph)
info:    at DataContractJsonSerializerTests.SerializeAndDeserialize[KeyValuePair`2](KeyValuePair`2 value, String baseline, DataContractJsonSerializerSettings settings, Func`1 serializerFactory, Boolean skipStringCompare)
info:    at DataContractJsonSerializerTests.DCJS_KeyValuePair()
info:    at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

The issue is this code:

runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ClassDataContract.cs

Lines 1400 to 1412 in a5e626a

	[RequiresUnreferencedCode(DataContract.SerializerTrimmerWarning)]
	private void SetKeyValuePairAdapterFlags(
	[DynamicallyAccessedMembers(DataContractPreserveMemberTypes)]
	Type type)
	{
	if (type.IsGenericType && type.GetGenericTypeDefinition() == Globals.TypeOfKeyValuePairAdapter)
	{
	_isKeyValuePairAdapter = true;
	_keyValuePairGenericArguments = type.GetGenericArguments();
	_keyValuePairCtorInfo = type.GetConstructor(Globals.ScanAllMembers, new Type[] { Globals.TypeOfKeyValuePair.MakeGenericType(_keyValuePairGenericArguments) });
	_getKeyValuePairMethodInfo = type.GetMethod("GetKeyValuePair", Globals.ScanAllMembers)!;
	}
	}

We need to annotate this so the linker will preserve the ctor on this class:

https://github.com/dotnet/wcf/blob/1948336f2c1a293cfe9c46774f0f664353620f6c/src/dotnet-svcutil/lib/src/FrameworkFork/System.Runtime.Serialization/System/Runtime/Serialization/CollectionDataContract.cs#L19-L21

cc @joperezr

Tagging subscribers to 'linkable-framework': @eerhardt, @vitek-karas, @LakshanF, @sbomer
See info in area-owners.md if you want to be subscribed.

Issue Details

---

See the test failing here.

fail: [FAIL] DataContractJsonSerializerTests.DCJS_KeyValuePair

info: System.NullReferenceException : Object reference not set to an instance of an object.
info:    at System.Runtime.Serialization.ReflectionClassWriter.ResolveAdapterType(Object obj, ClassDataContract classContract)
info:    at System.Runtime.Serialization.ReflectionClassWriter.ReflectionWriteClass(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context, ClassDataContract classContract, XmlDictionaryString[] memberNames)
info:    at System.Runtime.Serialization.Json.ReflectionJsonFormatWriter.ReflectionWriteClass(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, ClassDataContract classContract, XmlDictionaryString[] memberNames)
info:    at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.JsonDataContract.WriteJsonValue(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteJsonValue(JsonDataContract contract, XmlWriterDelegator writer, Object graph, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
info:    at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType, RuntimeTypeHandle declaredTypeHandle, Type declaredType)
info:    at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.SerializeWithXsiTypeAtTopLevel(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle originalDeclaredTypeHandle, Type graphType)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.InternalWriteObject(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.XmlObjectSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
info:    at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
info:    at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteObject(XmlDictionaryWriter writer, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializerImpl.WriteObject(Stream stream, Object graph)
info:    at System.Runtime.Serialization.Json.DataContractJsonSerializer.WriteObject(Stream stream, Object graph)
info:    at DataContractJsonSerializerTests.SerializeAndDeserialize[KeyValuePair`2](KeyValuePair`2 value, String baseline, DataContractJsonSerializerSettings settings, Func`1 serializerFactory, Boolean skipStringCompare)
info:    at DataContractJsonSerializerTests.DCJS_KeyValuePair()
info:    at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

The issue is this code:

runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ClassDataContract.cs

Lines 1400 to 1412 in a5e626a

	[RequiresUnreferencedCode(DataContract.SerializerTrimmerWarning)]
	private void SetKeyValuePairAdapterFlags(
	[DynamicallyAccessedMembers(DataContractPreserveMemberTypes)]
	Type type)
	{
	if (type.IsGenericType && type.GetGenericTypeDefinition() == Globals.TypeOfKeyValuePairAdapter)
	{
	_isKeyValuePairAdapter = true;
	_keyValuePairGenericArguments = type.GetGenericArguments();
	_keyValuePairCtorInfo = type.GetConstructor(Globals.ScanAllMembers, new Type[] { Globals.TypeOfKeyValuePair.MakeGenericType(_keyValuePairGenericArguments) });
	_getKeyValuePairMethodInfo = type.GetMethod("GetKeyValuePair", Globals.ScanAllMembers)!;
	}
	}

We need to annotate this so the linker will preserve the ctor on this class:

https://github.com/dotnet/wcf/blob/1948336f2c1a293cfe9c46774f0f664353620f6c/src/dotnet-svcutil/lib/src/FrameworkFork/System.Runtime.Serialization/System/Runtime/Serialization/CollectionDataContract.cs#L19-L21

cc @joperezr

Author:	eerhardt
Assignees:	-
Labels:	area-Serialization, linkable-framework, untriaged
Milestone:	-