Is there a way to find the implementation of methods with MethodImplOptions.InternalCall attribute?

Question

Background:
The Unity engine provides a number of PlayerPrefs.SetXxx functions that can be used to save user data. However, it will automatically append a hash to the name of what you saved. For example, a call of
PlayerPrefs.SetString("justTesting", "TEST!");
will add a registry value of
justTesting_h3837386411
on Windows platform.
Problem:
I know it's actually djb2-xor, but I am still curious about how the hash function is implemented. By using dnSpy I found PlayerPrefs.SetString, which is implemented in UnityEngine.CoreModule.dll, finally calls a native method declared as

[NativeMethod("SetString")]
[MethodImpl(MethodImplOptions.InternalCall)]
private static extern bool TrySetSetString(string key, string value);

And I'm stuck here. There's indeed a string UnityEngine.PlayerPrefs::TrySetSetString in .rdata section of UnityPlayer.dll, but I don't know where to find the actual code for it. What should I do next?

Answer 1

OK after some bold attempts I finally found it quite simple, at least on this Unity version. First, find the method name string and where it's referenced:

It is referenced at 11376594. But what's at this address? Here we go:

It's a string table. The next thing to do is to find out the table's start address, and then what references to this address. This guided me here: And here: This is a loop, which binds each function name to items in another table at 11371C40. This new table is a function table so I renamed it: Now it's reasonable to suspect this function table contains how each native method is implemented. By adding the string offset to the function table address, I got the bool TrySetSetString(string key, string value) address. Diving deeper and here is the hash algorithm: