Native AOT warnings

[IEvangelist]

One of the most compelling reasons for using this library is that it's Native-AOT compatible. However, I have an app that is consuming a client library generated by this library, and it's causing AOT warnings:

p/home/runner/.nuget/packages/microsoft.kiota.abstractions/1.7.2/lib/net5.0/Microsoft.Kiota.Abstractions.dll : warning IL2104: Assembly 'Microsoft.Kiota.Abstractions' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries [/home/runner/work/profanity-filter/profanity-filter/src/ProfanityFilter.Action/ProfanityFilter.Action.csproj]
/home/runner/.nuget/packages/microsoft.kiota.abstractions/1.7.2/lib/net5.0/Microsoft.Kiota.Abstractions.dll : warning IL3053: Assembly 'Microsoft.Kiota.Abstractions' produced AOT analysis warnings. [/home/runner/work/profanity-filter/profanity-filter/src/ProfanityFilter.Action/ProfanityFilter.Action.csproj]
/home/runner/.nuget/packages/octokit.net.sdk/0.0.4/lib/net8.0/Octokit.NET.SDK.dll : warning IL3053: Assembly 'Octokit.NET.SDK' produced AOT analysis warnings. [/home/runner/work/profanity-filter/profanity-filter/src/ProfanityFilter.Action/ProfanityFilter.Action.csproj]
/home/runner/.nuget/packages/microsoft.kiota.serialization.form/1.1.1/lib/net5.0/Microsoft.Kiota.Serialization.Form.dll : warning IL3053: Assembly 'Microsoft.Kiota.Serialization.Form' produced AOT analysis warnings. [/home/runner/work/profanity-filter/profanity-filter/src/ProfanityFilter.Action/ProfanityFilter.Action.csproj]
/home/runner/.nuget/packages/microsoft.kiota.serialization.json/1.1.2/lib/net5.0/Microsoft.Kiota.Serialization.Json.dll : warning IL3053: Assembly 'Microsoft.Kiota.Serialization.Json' produced AOT analysis warnings. [/home/runner/work/profanity-filter/profanity-filter/src/ProfanityFilter.Action/ProfanityFilter.Action.csproj]
/home/runner/.nuget/packages/microsoft.kiota.serialization.json/1.1.2/lib/net5.0/Microsoft.Kiota.Serialization.Json.dll : warning IL2104: Assembly 'Microsoft.Kiota.Serialization.Json' produced trim warnings. For more information see https://aka.ms/dotnet-illink/libraries

[eerhardt]

Here are the detailed warnings I see:

ILC : Trim analysis warning IL2091: Microsoft.Kiota.Abstractions.RequestInformation.Configure<T>(Action`1<RequestConfiguration`1<!!0>>): 'T' generic argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicProperties' in 'Microsoft.Kiota.Abstractions.RequestInformation.AddQueryParameters<T>(!!0)'. The generic parameter 'T' of 'Microsoft.Kiota.Abstractions.RequestInformation.Configure<T>(Action`1<RequestConfiguration`1<!!0>>)' does not have matching annotations. The source value must declare at least the same requirements as those declared on the target location it is assigned to.  
ILC : AOT analysis warning IL3050: Microsoft.Kiota.Abstractions.RequestInformation.ReplaceEnumValueByStringRepresentation(Object): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: Microsoft.Kiota.Abstractions.RequestInformation.ReplaceEnumValueByStringRepresentation(Object): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : Trim analysis warning IL2075: Microsoft.Kiota.Abstractions.RequestInformation.GetEnumName<T>(!!0): 'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicConstructors', 'DynamicallyAccessedMemberTypes.PublicMethods', 'DynamicallyAccessedMemberTypes.PublicFields', 'DynamicallyAccessedMemberTypes.PublicNestedTypes', 'DynamicallyAccessedMemberTypes.PublicProperties', 'DynamicallyAccessedMemberTypes.PublicEvents' in call to 'System.Type.GetMember(String)'. The return value of method 'System.Object.GetType()' does not have matching annotations. The source value must declare at least the same requirements as those declared on the target location it is assigned to.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.WithIssue_numberPatchRequestBody.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.WithIssue_numberPatchRequestBody.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Pulls.Item.WithPull_numberPatchRequestBody.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.Reactions.ReactionsPostRequestBody.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.PullRequest.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.PullRequest.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Issue.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Issue.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Reaction.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.IssueComment.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: Microsoft.Kiota.Serialization.Form.FormSerializationWriter.WriteEnumValue<T>(String,Nullable`1<!!0>): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: Microsoft.Kiota.Serialization.Json.JsonSerializationWriter.WriteEnumValue<T>(String,Nullable`1<!!0>): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.NullableMilestone.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.AutoMerge.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.Serialize(ISerializationWriter): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : Trim analysis warning IL2075: Microsoft.Kiota.Serialization.Json.JsonSerializationWriter.WriteNonParsableObjectValue<T>(String,!!0): 'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicProperties' in call to 'System.Type.GetProperties()'. The return value of method 'System.Object.GetType()' does not have matching annotations. The source value must declare at least the same requirements as those declared on the target location it is assigned to.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.<GetFieldDeserializers>b__354_50(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.<GetFieldDeserializers>b__354_51(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.<GetFieldDeserializers>b__354_67(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository_template_repository.<GetFieldDeserializers>b__354_68(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.NullableMilestone.<GetFieldDeserializers>b__70_12(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.<GetFieldDeserializers>b__402_56(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.<GetFieldDeserializers>b__402_57(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.<GetFieldDeserializers>b__402_75(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Repository.<GetFieldDeserializers>b__402_76(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.AutoMerge.<GetFieldDeserializers>b__22_3(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.IssueComment.<GetFieldDeserializers>b__62_0(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Reaction.<GetFieldDeserializers>b__26_0(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Issue.<GetFieldDeserializers>b__142_3(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.Issue.<GetFieldDeserializers>b__142_28(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.PullRequest.<GetFieldDeserializers>b__198_4(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Models.PullRequest.<GetFieldDeserializers>b__198_42(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.Reactions.ReactionsPostRequestBody.<GetFieldDeserializers>b__10_0(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Pulls.Item.WithPull_numberPatchRequestBody.<GetFieldDeserializers>b__26_3(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.WithIssue_numberPatchRequestBody.<GetFieldDeserializers>b__38_5(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  
ILC : AOT analysis warning IL3050: GitHub.Repos.Item.Item.Issues.Item.WithIssue_numberPatchRequestBody.<GetFieldDeserializers>b__38_6(IParseNode): Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. It might not be possible to create an array of the enum type at runtime. Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.  

[IEvangelist]

It looks like most (if not all) of them are related to System.Enum.GetValues(Type). Is that easy to fix, do we already have a mechanism in place for enum support that doesn't require reflection?

[IEvangelist]

I went digging a bit, and found that this bit of code in the Microsoft.Kiota.Abstractions library, it seems to be correct:

Microsoft.Kiota.Abstractions

[baywet]

Hi everyone,
Thanks for using kiota and for reaching out.
I'm not sure why it's complaining about a reference to Enum.GetValues since it's not used in RequestInformation.
For sanity, can you try to force the Microsoft.Kiota.Abstractions dependency to its latest version (1.7.6) and see if you still see the first warning please?

[baywet]

As per the warnings in Json/Form serialization, most of them are due to this (and equivalent in form)
I thought the point of adding the annotations/attributes was so the compiler knows not to trim things?

[eerhardt]

The Enum.GetValues(Type) warning is the same as the case study in https://devblogs.microsoft.com/dotnet/creating-aot-compatible-libraries/#dotnet-extensions, the last example in that section.

Lastly, some code was inspecting all the values of an enum. In earlier versions of .NET, the way to do this was to call Enum.GetValues(typeof(MyEnum)). However, this API isn’t compatible with AOT because an array of MyEnum needs to be created at runtime, and the AOT code might not contain the specific code for MyEnum[].

---

I went digging a bit, and found that this bit of code in the Microsoft.Kiota.Abstractions library, it seems to be correct:
Microsoft.Kiota.Abstractions

The issue here is that the annotations are for the T type, but the actual code doing Reflection is working on the var type = value.GetType();. Usually, these can be different types because of inheritance.

public class MyBase {}
public class MyDerived : MyBase {}

private void Foo<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T>(T value)
{
    var type = value.GetType();
}

MyBase b = new MyDerived();
Foo(b);

In the above example T == typeof(MyBase), but var type == typeof(MyDerived). So that's why there is a warning here - you can't statically know which type value will be at runtime. The fix there is to use var type = typeof(T); instead.

(Side note, since this actual code has where T : Enum you could argue that the tools should be smart enough that T and value.GetType() will always be equal, since enums can't participate in inheritance.)

[baywet]

Thanks for the details here!
@IEvangelist do you want to start with a PR to this replacing the GetType by a typeof instead?

[IEvangelist]

Thanks for the details here! @IEvangelist do you want to start with a PR to this replacing the GetType by a typeof instead?

Sure, @baywet - see microsoft/kiota-dotnet#184

[baywet]

Update for everyone: with the help @IEvangelist and others we've fixed the code across the multiple kiota libraries. This will get closed as the last PR gets merged. Feel free to comment on this issue if you're still seeing warnings.

[IEvangelist]

FYI @nickfloyd

[iPaul-777]

@IEvangelist's answer works but not useful in some instances. If you know the type, typeof(mytype) does, indeed, work. But, with non-native code, it also accepts object.GetType() so the object can be anything and it just works. If you want to continue handling all types with native AOT, you now have to have a big switch statement with all of your types, using typeof(type) for each. Is there any generic solution??