.NET Fusion logger: What is the difference between Default and Native Images?

Question

In the .NET fusion logger (FUSLOGVW.exe) what do the two options in the lower right of the screen do?

 Log Categories
  + Default
  + Native Images

And how can I use either one to diagnose a mixed-mode assembly problem?

Attentive

possible duplicate of What is the meaning of Default/NativeImage in fuslogvw? – Coriolanus

The questions ARE similar, but the accepted answer starts with "I think." This one already has a much more detailed answer. – Attentive

Answer 1

Native images are the files generated by ngen.exe. It contains pre-compiled machine code for an assembly, so that the JIT compiler isn't needed. All .NET framework assemblies are ngen-ed. They have the .ni.dll filename extension.

You are typically not interested in them if you are trying to troubleshoot an assembly resolution problem. But you can see them getting loaded if you choose "Native Images" instead of "Default".

Festschrift

Where do mixed mode assemblies fall between those options? – Attentive

They are just another assembly that contains IL. Fusion doesn't care about the unmanaged bits in it. – Festschrift