What assembly is this RuntimeAssembly?

Say that you are debugging a .NET application in windbg and happen to have a System.Reflection.RuntimeAssembly (the actual implementation of System.Reflection.Assembly) and you want to find out which assembly it actually references. You could try dumping the object (i'm using the sosex extension here):

That wasn't very helpful. The object is just a thin wrapper around the native object pointed to by m_assembly. So what is this object? This is what it looks like:

A good trick is to check whether the first value is a vtable pointer:

So apparently the object is a DomainAssembly object, whatever that is (you can find some of these classes in the Rotor source, but the structure of them are vastly different). Using this trick combined with the !mln sosex command we find:

The PEAssembly object:

CAssemblyName? That sounds promising, right?


There was the name. And we had a pointer to the AppDomain earlier, so that should be sufficient to uniquely identify the assembly. I haven't figured out where the actual assembly or module objects as used by !DumpAssembly and !DumpModule resides, but they are probably somewhere in there (the modules are CModule objects, the assembly objects starts with a null pointer, so I couldn't tell the C++ class from that).