Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/linker/cecil/rocks/Mono.Cecil.Rocks/MethodDefinitionRocks.cs

@@ -0,0 +1,72 @@
+//
+// Author:
+//   Jb Evain (jbevain@gmail.com)
+//
+// Copyright (c) 2008 - 2015 Jb Evain
+// Copyright (c) 2008 - 2011 Novell, Inc.
+//
+// Licensed under the MIT/X11 license.
+//
+
+using System;
+
+namespace Mono.Cecil.Rocks {
+
+#if INSIDE_ROCKS
+	public
+#endif
+	static class MethodDefinitionRocks {
+
+		public static MethodDefinition GetBaseMethod (this MethodDefinition self)
+		{
+			if (self == null)
+				throw new ArgumentNullException ("self");
+			if (!self.IsVirtual)
+				return self;
+			if (self.IsNewSlot)
+				return self;
+
+			var base_type = ResolveBaseType (self.DeclaringType);
+			while (base_type != null) {
+				var @base = GetMatchingMethod (base_type, self);
+				if (@base != null)
+					return @base;
+
+				base_type = ResolveBaseType (base_type);
+			}
+
+			return self;
+		}
+
+		public static MethodDefinition GetOriginalBaseMethod (this MethodDefinition self)
+		{
+			if (self == null)
+				throw new ArgumentNullException ("self");
+
+			while (true) {
+				var @base = self.GetBaseMethod ();
+				if (@base == self)
+					return self;
+
+				self = @base;
+			}
+		}
+
+		static TypeDefinition ResolveBaseType (TypeDefinition type)
+		{
+			if (type == null)
+				return null;
+
+			var base_type = type.BaseType;
+			if (base_type == null)
+				return null;
+
+			return base_type.Resolve ();
+		}
+
+		static MethodDefinition GetMatchingMethod (TypeDefinition type, MethodDefinition method)
+		{
+			return MetadataResolver.GetMethod (type.Methods, method);
+		}
+	}
+}