Implement reflection properly for fields.

- FieldAccessorTable is now non-generic
- We don't have a static field per message type in the umbrella class. (Message descriptors are accessed via the file descriptor.)
- Removed the "descriptor assigner" complication from the descriptor fixup; without extensions, we don't need it
- MapField implements IDictionary (more tests would be good...)
- RepeatedField implements IList (more tests would be good)
- Use expression trees to build accessors. (Will need to test this on various platforms... probably need a fallback strategy just using reflection directly.)
- Added FieldDescriptor.IsMap
- Added tests for reflection with generated messages

Changes to generated code coming in next commit.

1 files changed, 13 insertions, 10 deletions

diff --git a/csharp/src/ProtocolBuffers/FieldAccess/FieldAccessorBase.cs b/csharp/src/ProtocolBuffers/FieldAccess/FieldAccessorBase.cs
index 73d777b2..2a3e5b8b 100644
--- a/csharp/src/ProtocolBuffers/FieldAccess/FieldAccessorBase.cs
+++ b/csharp/src/ProtocolBuffers/FieldAccess/FieldAccessorBase.cs
@@ -32,34 +32,37 @@
 
 using System;
 using System.Reflection;
+using Google.Protobuf.Descriptors;
 
 namespace Google.Protobuf.FieldAccess
 {
     /// <summary>
     /// Base class for field accessors.
     /// </summary>
-    /// <typeparam name="T">Type of message containing the field</typeparam>
-    internal abstract class FieldAccessorBase<T> : IFieldAccessor<T> where T : IMessage<T>
+    internal abstract class FieldAccessorBase : IFieldAccessor
     {
-        private readonly Func<T, object> getValueDelegate;
+        private readonly Func<object, object> getValueDelegate;
+        private readonly FieldDescriptor descriptor;
 
-        internal FieldAccessorBase(string name)
+        internal FieldAccessorBase(Type type, string propertyName, FieldDescriptor descriptor)
         {
-            PropertyInfo property = typeof(T).GetProperty(name);
+            PropertyInfo property = type.GetProperty(propertyName);
             if (property == null || !property.CanRead)
             {
                 throw new ArgumentException("Not all required properties/methods available");
             }
-            getValueDelegate = ReflectionUtil.CreateUpcastDelegate<T>(property.GetGetMethod());
+            this.descriptor = descriptor;
+            getValueDelegate = ReflectionUtil.CreateFuncObjectObject(property.GetGetMethod());
         }
 
-        public object GetValue(T message)
+        public FieldDescriptor Descriptor { get { return descriptor; } }
+
+        public object GetValue(object message)
         {
             return getValueDelegate(message);
         }
 
-        public abstract bool HasValue(T message);
-        public abstract void Clear(T message);
-        public abstract void SetValue(T message, object value);
+        public abstract void Clear(object message);
+        public abstract void SetValue(object message, object value);
     }
 }