Execute RegisterImplementationSourceOutput last?

[weifenluo]

When will source generator with RegisterImplementationSourceOutput get executed? Can I get it executed after other source generator(s)? Came across with #57963 and #54723, I still can't get a clear picture.

For simplicity, let's say I have two incremental source generators: KeyGenerator and TypeDescriptorGenerator. Given the following input source code:

public partial class MyEntityType : IEntityType
{
    public Field<int> Id { get; private set; }

    public Field<string> Name { get; private set; }

    [GenerateKey(nameof(Id))]
    public partial class Key : IEntityType
    {
    }
}

The KeyGenerator will take the [GenerateKey] marker attribute to generate the following code, based on the field name(s) provided:

// <AutoGenerated/>
partial class Key
{
    // copy from containing MyEntityType:
    public Field<int> Id { get; private set; }
}

The TypeDescriptorGenerator, on the other hand, will take all types which implements IEntityType, taking all the fields of the type, to generate a type descriptor class. The generated type descriptor class is invisible to developer, so it's registered with RegisterImplementationSourceOutput. The generation should take the output Compilation of KeyGenerator, because it should take the generated Key.Id property into account; this code generation is expensive, for performance consideration, ideally it should only run once.

So back to the question: can I have TypeDescriptorGenerator only run at the end of compile pipeline? If yes, how? If no, what's the workaround?

[Dreamescaper]

Source Generators do not affect each other at all:
#57239