no more submodule

GtkSharp/Source/Libs/GLibSharp/AbiStructExtensions.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace GLib
+{
+
+    public static class AbiStructExtension
+    {
+        public static N BaseOverride<N>(this AbiStruct class_abi, GType gtype, string fieldname) where N : Delegate
+        {
+            N unmanaged = null;
+            unsafe {
+                IntPtr raw_ptr = IntPtr.Zero;
+                while (raw_ptr == IntPtr.Zero && GType.IsManaged(gtype)) {
+                    gtype = gtype.GetThresholdType();
+                    var abi_ptr = (IntPtr*) (((long) gtype.GetClassPtr()) + (long) class_abi.GetFieldOffset(fieldname));
+                    raw_ptr = *abi_ptr;
+                }
+
+                if (raw_ptr != IntPtr.Zero) {
+                    unmanaged = Marshal.GetDelegateForFunctionPointer<N>(raw_ptr);
+                }
+            }
+
+            return unmanaged;
+        }
+    }
+}