Update //third_party/protobuf to version 3.

third_party/protobuf/csharp/src/Google.Protobuf/Reflection/ReflectionUtil.cs

+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// The methods in this class are somewhat evil, and should not be tampered with lightly.
+    /// Basically they allow the creation of relatively weakly typed delegates from MethodInfos
+    /// which are more strongly typed. They do this by creating an appropriate strongly typed
+    /// delegate from the MethodInfo, and then calling that within an anonymous method.
+    /// Mind-bending stuff (at least to your humble narrator) but the resulting delegates are
+    /// very fast compared with calling Invoke later on.
+    /// </summary>
+    internal static class ReflectionUtil
+    {
+        /// <summary>
+        /// Empty Type[] used when calling GetProperty to force property instead of indexer fetching.
+        /// </summary>
+        internal static readonly Type[] EmptyTypes = new Type[0];
+
+        /// <summary>
+        /// Creates a delegate which will cast the argument to the appropriate method target type,
+        /// call the method on it, then convert the result to object.
+        /// </summary>
+        internal static Func<IMessage, object> CreateFuncIMessageObject(MethodInfo method)
+        {
+            ParameterExpression parameter = Expression.Parameter(typeof(IMessage), "p");
+            Expression downcast = Expression.Convert(parameter, method.DeclaringType);
+            Expression call = Expression.Call(downcast, method);
+            Expression upcast = Expression.Convert(call, typeof(object));
+            return Expression.Lambda<Func<IMessage, object>>(upcast, parameter).Compile();
+        }
+
+        /// <summary>
+        /// Creates a delegate which will cast the argument to the appropriate method target type,
+        /// call the method on it, then convert the result to the specified type.
+        /// </summary>
+        internal static Func<IMessage, T> CreateFuncIMessageT<T>(MethodInfo method)
+        {
+            ParameterExpression parameter = Expression.Parameter(typeof(IMessage), "p");
+            Expression downcast = Expression.Convert(parameter, method.DeclaringType);
+            Expression call = Expression.Call(downcast, method);
+            Expression upcast = Expression.Convert(call, typeof(T));
+            return Expression.Lambda<Func<IMessage, T>>(upcast, parameter).Compile();
+        }
+
+        /// <summary>
+        /// Creates a delegate which will execute the given method after casting the first argument to
+        /// the target type of the method, and the second argument to the first parameter type of the method.
+        /// </summary>
+        internal static Action<IMessage, object> CreateActionIMessageObject(MethodInfo method)
+        {
+            ParameterExpression targetParameter = Expression.Parameter(typeof(IMessage), "target");
+            ParameterExpression argParameter = Expression.Parameter(typeof(object), "arg");
+            Expression castTarget = Expression.Convert(targetParameter, method.DeclaringType);
+            Expression castArgument = Expression.Convert(argParameter, method.GetParameters()[0].ParameterType);
+            Expression call = Expression.Call(castTarget, method, castArgument);
+            return Expression.Lambda<Action<IMessage, object>>(call, targetParameter, argParameter).Compile();
+        }
+
+        /// <summary>
+        /// Creates a delegate which will execute the given method after casting the first argument to
+        /// the target type of the method.
+        /// </summary>
+        internal static Action<IMessage> CreateActionIMessage(MethodInfo method)
+        {
+            ParameterExpression targetParameter = Expression.Parameter(typeof(IMessage), "target");
+            Expression castTarget = Expression.Convert(targetParameter, method.DeclaringType);
+            Expression call = Expression.Call(castTarget, method);
+            return Expression.Lambda<Action<IMessage>>(call, targetParameter).Compile();
+        }        
+    }
+}