Bug IL2CPP completely ignores P/Invoke metadata

1.

Code (CSharp):

1.         [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]
2.         [return: MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(LaxUtf8NoCleanupMarshaler))]
3.         internal static extern unsafe string git_reference_name(git_reference* reference);

Code snippet from LibGit2Sharp.
MarshalAs here is completely ignored, and runtime will try to free returned string, causing crash.

2.

Code (CSharp):

1.         [DllImport(libgit2, CallingConvention = CallingConvention.Cdecl)]
2.         internal static extern int git_repository_discover(
3.             GitBuf buf,
4.             [MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(StrictFilePathMarshaler))] FilePath start_path,
5.             [MarshalAs(UnmanagedType.Bool)] bool across_fs,
6.             [MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(StrictFilePathMarshaler))] FilePath ceiling_dirs);

Code snippet from LibGit2Sharp.

Custom marshallers are all ignored, compiled app will throw exception complaining 'dont know how to marshal FilePath'

3.

Code (CSharp):

1.         [UnmanagedFunctionPointer(CallingConvention.Cdecl, CharSet = CharSet.Unicode)]
2.         private delegate void Py_SetPath(string home);
3.        
4.         public void SetPath(string home) {
5.             var pFunc = loader.GetFunction(hLibPython, "Py_SetPath");
6.             var func = Marshal.GetDelegateForFunctionPointer<Py_SetPath>(pFunc);
7.             func(home);
8.         }

IL2CPP will just marshal the string in UTF8.


All the three places are working normally in Mono runtime.

 

I don't think Process is supported in IL2CPP:

https://forum.unity.com/threads/solved-il2cpp-and-process-start.533988/

 

Wrong thread ?

 

Isn't P/Invoke and any metadata functionality fairly closely associated with the Process class?

Well, if it's not helpful, carry on!

 

Well, no.... No processes are involved in my case