Ported .Net Core commits:

hondacrx:
- Initial commit: Switch to .Net Core 2.0
- Fix build and removed not needed files
Fabi:
- Updated solution platforms.
- Changed folder structure.
- Change library target framework to netstandard2.0.
- Updated solution platforms again...
- Removed windows specific kernel32 function usage (Ctrl-C handler).

Deps/Source/Google.Protobuf/Reflection/CustomOptions.cs

@@ -0,0 +1,390 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2017 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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Container for a set of custom options specified within a message, field etc.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// This type is publicly immutable, but internally mutable. It is only populated
+    /// by the descriptor parsing code - by the time any user code is able to see an instance,
+    /// it will be fully initialized.
+    /// </para>
+    /// <para>
+    /// If an option is requested using the incorrect method, an answer may still be returned: all
+    /// of the numeric types are represented internally using 64-bit integers, for example. It is up to
+    /// the caller to ensure that they make the appropriate method call for the option they're interested in.
+    /// Note that enum options are simply stored as integers, so the value should be fetched using
+    /// <see cref="TryGetInt32(int, out int)"/> and then cast appropriately.
+    /// </para>
+    /// <para>
+    /// Repeated options are currently not supported. Asking for a single value of an option
+    /// which was actually repeated will return the last value, except for message types where
+    /// all the set values are merged together.
+    /// </para>
+    /// </remarks>
+    public sealed class CustomOptions
+    {
+        /// <summary>
+        /// Singleton for all descriptors with an empty set of options.
+        /// </summary>
+        internal static readonly CustomOptions Empty = new CustomOptions();
+        
+        /// <summary>
+        /// A sequence of values per field. This needs to be per field rather than per tag to allow correct deserialization
+        /// of repeated fields which could be "int, ByteString, int" - unlikely as that is. The fact that values are boxed
+        /// is unfortunate; we might be able to use a struct instead, and we could combine uint and ulong values.
+        /// </summary>
+        private readonly Dictionary<int, List<FieldValue>> valuesByField = new Dictionary<int, List<FieldValue>>();
+
+        private CustomOptions() { }
+
+        /// <summary>
+        /// Retrieves a Boolean value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetBool(int field, out bool value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = tmp == 1UL;
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a signed 32-bit integer value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetInt32(int field, out int value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = (int) tmp.GetValueOrDefault();
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a signed 64-bit integer value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetInt64(int field, out long value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = (long) tmp.GetValueOrDefault();
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves an unsigned 32-bit integer value for the specified option field,
+        /// assuming a fixed-length representation.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetFixed32(int field, out uint value) => TryGetUInt32(field, out value);
+
+        /// <summary>
+        /// Retrieves an unsigned 64-bit integer value for the specified option field,
+        /// assuming a fixed-length representation.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetFixed64(int field, out ulong value) => TryGetUInt64(field, out value);
+
+        /// <summary>
+        /// Retrieves a signed 32-bit integer value for the specified option field,
+        /// assuming a fixed-length representation.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetSFixed32(int field, out int value) => TryGetInt32(field, out value);
+
+        /// <summary>
+        /// Retrieves a signed 64-bit integer value for the specified option field,
+        /// assuming a fixed-length representation.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetSFixed64(int field, out long value) => TryGetInt64(field, out value);
+        
+        /// <summary>
+        /// Retrieves a signed 32-bit integer value for the specified option field,
+        /// assuming a zigzag encoding.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetSInt32(int field, out int value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = CodedInputStream.DecodeZigZag32((uint) tmp.GetValueOrDefault());
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a signed 64-bit integer value for the specified option field,
+        /// assuming a zigzag encoding.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetSInt64(int field, out long value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = CodedInputStream.DecodeZigZag64(tmp.GetValueOrDefault());
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves an unsigned 32-bit integer value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetUInt32(int field, out uint value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = (uint) tmp.GetValueOrDefault();
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves an unsigned 64-bit integer value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetUInt64(int field, out ulong value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = tmp.GetValueOrDefault();
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a 32-bit floating point value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetFloat(int field, out float value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            int int32 = (int) tmp.GetValueOrDefault();
+            byte[] bytes = BitConverter.GetBytes(int32);
+            value = BitConverter.ToSingle(bytes, 0);
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a 64-bit floating point value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetDouble(int field, out double value)
+        {
+            ulong? tmp = GetLastNumericValue(field);
+            value = BitConverter.Int64BitsToDouble((long) tmp.GetValueOrDefault());
+            return tmp != null;
+        }
+
+        /// <summary>
+        /// Retrieves a string value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetString(int field, out string value)
+        {
+            ByteString bytes = GetLastByteStringValue(field);
+            value = bytes?.ToStringUtf8();
+            return bytes != null;
+        }
+
+        /// <summary>
+        /// Retrieves a bytes value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetBytes(int field, out ByteString value)
+        {
+            ByteString bytes = GetLastByteStringValue(field);
+            value = bytes;
+            return bytes != null;
+        }
+
+        /// <summary>
+        /// Retrieves a message value for the specified option field.
+        /// </summary>
+        /// <param name="field">The field to fetch the value for.</param>
+        /// <param name="value">The output variable to populate.</param>
+        /// <returns><c>true</c> if a suitable value for the field was found; <c>false</c> otherwise.</returns>
+        public bool TryGetMessage<T>(int field, out T value) where T : class, IMessage, new()
+        {
+            value = null;
+            List<FieldValue> values;
+            if (!valuesByField.TryGetValue(field, out values))
+            {
+                return false;
+            }
+            foreach (FieldValue fieldValue in values)
+            {
+                if (fieldValue.ByteString != null)
+                {
+                    if (value == null)
+                    {
+                        value = new T();
+                    }
+                    value.MergeFrom(fieldValue.ByteString);
+                }
+            }
+            return value != null;
+        }
+
+        private ulong? GetLastNumericValue(int field)
+        {
+            List<FieldValue> values;
+            if (!valuesByField.TryGetValue(field, out values))
+            {
+                return null;
+            }
+            for (int i = values.Count - 1; i >= 0; i--)
+            {
+                // A non-bytestring value is a numeric value
+                if (values[i].ByteString == null)
+                {
+                    return values[i].Number;
+                }
+            }
+            return null;
+        }
+
+        private ByteString GetLastByteStringValue(int field)
+        {
+            List<FieldValue> values;
+            if (!valuesByField.TryGetValue(field, out values))
+            {
+                return null;
+            }
+            for (int i = values.Count - 1; i >= 0; i--)
+            {
+                if (values[i].ByteString != null)
+                {
+                    return values[i].ByteString;
+                }
+            }
+            return null;
+        }
+
+        /// <summary>
+        /// Reads an unknown field, either parsing it and storing it or skipping it.
+        /// </summary>
+        /// <remarks>
+        /// If the current set of options is empty and we manage to read a field, a new set of options
+        /// will be created and returned. Otherwise, the return value is <c>this</c>. This allows
+        /// us to start with a singleton empty set of options and just create new ones where necessary.
+        /// </remarks>
+        /// <param name="input">Input stream to read from. </param>
+        /// <returns>The resulting set of custom options, either <c>this</c> or a new set.</returns>
+        internal CustomOptions ReadOrSkipUnknownField(CodedInputStream input)
+        {
+            var tag = input.LastTag;
+            var field = WireFormat.GetTagFieldNumber(tag);
+            switch (WireFormat.GetTagWireType(tag))
+            {
+                case WireFormat.WireType.LengthDelimited:
+                    return AddValue(field, new FieldValue(input.ReadBytes()));
+                case WireFormat.WireType.Fixed32:
+                    return AddValue(field, new FieldValue(input.ReadFixed32()));
+                case WireFormat.WireType.Fixed64:
+                    return AddValue(field, new FieldValue(input.ReadFixed64()));
+                case WireFormat.WireType.Varint:
+                    return AddValue(field, new FieldValue(input.ReadRawVarint64()));
+                // For StartGroup, EndGroup or any wire format we don't understand,
+                // just use the normal behavior (call SkipLastField).
+                default:
+                    input.SkipLastField();
+                    return this;
+            }
+        }
+
+        private CustomOptions AddValue(int field, FieldValue value)
+        {
+            var ret = valuesByField.Count == 0 ? new CustomOptions() : this;
+            List<FieldValue> valuesForField;
+            if (!ret.valuesByField.TryGetValue(field, out valuesForField))
+            {
+                // Expect almost all 
+                valuesForField = new List<FieldValue>(1);
+                ret.valuesByField[field] = valuesForField;
+            }
+            valuesForField.Add(value);
+            return ret;
+        }
+
+        /// <summary>
+        /// All field values can be stored as a byte string or a 64-bit integer.
+        /// This struct avoids unnecessary boxing.
+        /// </summary>
+        private struct FieldValue
+        {
+            internal ulong Number { get; }
+            internal ByteString ByteString { get; }
+
+            internal FieldValue(ulong number)
+            {
+                Number = number;
+                ByteString = null;
+            }
+
+            internal FieldValue(ByteString byteString)
+            {
+                Number = 0;
+                ByteString = byteString;
+            }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/DescriptorBase.cs

@@ -0,0 +1,85 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Base class for nearly all descriptors, providing common functionality.
+    /// </summary>
+    public abstract class DescriptorBase : IDescriptor
+    {
+        private readonly FileDescriptor file;
+        private readonly string fullName;
+        private readonly int index;
+
+        internal DescriptorBase(FileDescriptor file, string fullName, int index)
+        {
+            this.file = file;
+            this.fullName = fullName;
+            this.index = index;
+        }
+
+        /// <value>
+        /// The index of this descriptor within its parent descriptor. 
+        /// </value>
+        /// <remarks>
+        /// This returns the index of this descriptor within its parent, for
+        /// this descriptor's type. (There can be duplicate values for different
+        /// types, e.g. one enum type with index 0 and one message type with index 0.)
+        /// </remarks>
+        public int Index
+        {
+            get { return index; }
+        }
+
+        /// <summary>
+        /// Returns the name of the entity (field, message etc) being described.
+        /// </summary>
+        public abstract string Name { get; }
+
+        /// <summary>
+        /// The fully qualified name of the descriptor's target.
+        /// </summary>
+        public string FullName
+        {
+            get { return fullName; }
+        }
+
+        /// <value>
+        /// The file this descriptor was declared in.
+        /// </value>
+        public FileDescriptor File
+        {
+            get { return file; }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/DescriptorPool.cs

@@ -0,0 +1,368 @@
+#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.Text;
+using System.Text.RegularExpressions;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Contains lookup tables containing all the descriptors defined in a particular file.
+    /// </summary>
+    internal sealed class DescriptorPool
+    {
+        private readonly IDictionary<string, IDescriptor> descriptorsByName =
+            new Dictionary<string, IDescriptor>();
+
+        private readonly IDictionary<DescriptorIntPair, FieldDescriptor> fieldsByNumber =
+            new Dictionary<DescriptorIntPair, FieldDescriptor>();
+
+        private readonly IDictionary<DescriptorIntPair, EnumValueDescriptor> enumValuesByNumber =
+            new Dictionary<DescriptorIntPair, EnumValueDescriptor>();
+
+        private readonly HashSet<FileDescriptor> dependencies;
+
+        internal DescriptorPool(FileDescriptor[] dependencyFiles)
+        {
+            dependencies = new HashSet<FileDescriptor>();
+            for (int i = 0; i < dependencyFiles.Length; i++)
+            {
+                dependencies.Add(dependencyFiles[i]);
+                ImportPublicDependencies(dependencyFiles[i]);
+            }
+
+            foreach (FileDescriptor dependency in dependencyFiles)
+            {
+                AddPackage(dependency.Package, dependency);
+            }
+        }
+
+        private void ImportPublicDependencies(FileDescriptor file)
+        {
+            foreach (FileDescriptor dependency in file.PublicDependencies)
+            {
+                if (dependencies.Add(dependency))
+                {
+                    ImportPublicDependencies(dependency);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Finds a symbol of the given name within the pool.
+        /// </summary>
+        /// <typeparam name="T">The type of symbol to look for</typeparam>
+        /// <param name="fullName">Fully-qualified name to look up</param>
+        /// <returns>The symbol with the given name and type,
+        /// or null if the symbol doesn't exist or has the wrong type</returns>
+        internal T FindSymbol<T>(string fullName) where T : class
+        {
+            IDescriptor result;
+            descriptorsByName.TryGetValue(fullName, out result);
+            T descriptor = result as T;
+            if (descriptor != null)
+            {
+                return descriptor;
+            }
+
+            // dependencies contains direct dependencies and any *public* dependencies
+            // of those dependencies (transitively)... so we don't need to recurse here.
+            foreach (FileDescriptor dependency in dependencies)
+            {
+                dependency.DescriptorPool.descriptorsByName.TryGetValue(fullName, out result);
+                descriptor = result as T;
+                if (descriptor != null)
+                {
+                    return descriptor;
+                }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Adds a package to the symbol tables. If a package by the same name
+        /// already exists, that is fine, but if some other kind of symbol
+        /// exists under the same name, an exception is thrown. If the package
+        /// has multiple components, this also adds the parent package(s).
+        /// </summary>
+        internal void AddPackage(string fullName, FileDescriptor file)
+        {
+            int dotpos = fullName.LastIndexOf('.');
+            String name;
+            if (dotpos != -1)
+            {
+                AddPackage(fullName.Substring(0, dotpos), file);
+                name = fullName.Substring(dotpos + 1);
+            }
+            else
+            {
+                name = fullName;
+            }
+
+            IDescriptor old;
+            if (descriptorsByName.TryGetValue(fullName, out old))
+            {
+                if (!(old is PackageDescriptor))
+                {
+                    throw new DescriptorValidationException(file,
+                                                            "\"" + name +
+                                                            "\" is already defined (as something other than a " +
+                                                            "package) in file \"" + old.File.Name + "\".");
+                }
+            }
+            descriptorsByName[fullName] = new PackageDescriptor(name, fullName, file);
+        }
+
+        /// <summary>
+        /// Adds a symbol to the symbol table.
+        /// </summary>
+        /// <exception cref="DescriptorValidationException">The symbol already existed
+        /// in the symbol table.</exception>
+        internal void AddSymbol(IDescriptor descriptor)
+        {
+            ValidateSymbolName(descriptor);
+            String fullName = descriptor.FullName;
+
+            IDescriptor old;
+            if (descriptorsByName.TryGetValue(fullName, out old))
+            {
+                int dotPos = fullName.LastIndexOf('.');
+                string message;
+                if (descriptor.File == old.File)
+                {
+                    if (dotPos == -1)
+                    {
+                        message = "\"" + fullName + "\" is already defined.";
+                    }
+                    else
+                    {
+                        message = "\"" + fullName.Substring(dotPos + 1) + "\" is already defined in \"" +
+                                  fullName.Substring(0, dotPos) + "\".";
+                    }
+                }
+                else
+                {
+                    message = "\"" + fullName + "\" is already defined in file \"" + old.File.Name + "\".";
+                }
+                throw new DescriptorValidationException(descriptor, message);
+            }
+            descriptorsByName[fullName] = descriptor;
+        }
+
+        private static readonly Regex ValidationRegex = new Regex("^[_A-Za-z][_A-Za-z0-9]*$",
+                                                                  FrameworkPortability.CompiledRegexWhereAvailable);
+
+        /// <summary>
+        /// Verifies that the descriptor's name is valid (i.e. it contains
+        /// only letters, digits and underscores, and does not start with a digit).
+        /// </summary>
+        /// <param name="descriptor"></param>
+        private static void ValidateSymbolName(IDescriptor descriptor)
+        {
+            if (descriptor.Name == "")
+            {
+                throw new DescriptorValidationException(descriptor, "Missing name.");
+            }
+            if (!ValidationRegex.IsMatch(descriptor.Name))
+            {
+                throw new DescriptorValidationException(descriptor,
+                                                        "\"" + descriptor.Name + "\" is not a valid identifier.");
+            }
+        }
+
+        /// <summary>
+        /// Returns the field with the given number in the given descriptor,
+        /// or null if it can't be found.
+        /// </summary>
+        internal FieldDescriptor FindFieldByNumber(MessageDescriptor messageDescriptor, int number)
+        {
+            FieldDescriptor ret;
+            fieldsByNumber.TryGetValue(new DescriptorIntPair(messageDescriptor, number), out ret);
+            return ret;
+        }
+
+        internal EnumValueDescriptor FindEnumValueByNumber(EnumDescriptor enumDescriptor, int number)
+        {
+            EnumValueDescriptor ret;
+            enumValuesByNumber.TryGetValue(new DescriptorIntPair(enumDescriptor, number), out ret);
+            return ret;
+        }
+
+        /// <summary>
+        /// Adds a field to the fieldsByNumber table.
+        /// </summary>
+        /// <exception cref="DescriptorValidationException">A field with the same
+        /// containing type and number already exists.</exception>
+        internal void AddFieldByNumber(FieldDescriptor field)
+        {
+            DescriptorIntPair key = new DescriptorIntPair(field.ContainingType, field.FieldNumber);
+            FieldDescriptor old;
+            if (fieldsByNumber.TryGetValue(key, out old))
+            {
+                throw new DescriptorValidationException(field, "Field number " + field.FieldNumber +
+                                                               "has already been used in \"" +
+                                                               field.ContainingType.FullName +
+                                                               "\" by field \"" + old.Name + "\".");
+            }
+            fieldsByNumber[key] = field;
+        }
+
+        /// <summary>
+        /// Adds an enum value to the enumValuesByNumber table. If an enum value
+        /// with the same type and number already exists, this method does nothing.
+        /// (This is allowed; the first value defined with the number takes precedence.)
+        /// </summary>
+        internal void AddEnumValueByNumber(EnumValueDescriptor enumValue)
+        {
+            DescriptorIntPair key = new DescriptorIntPair(enumValue.EnumDescriptor, enumValue.Number);
+            if (!enumValuesByNumber.ContainsKey(key))
+            {
+                enumValuesByNumber[key] = enumValue;
+            }
+        }
+
+        /// <summary>
+        /// Looks up a descriptor by name, relative to some other descriptor.
+        /// The name may be fully-qualified (with a leading '.'), partially-qualified,
+        /// or unqualified. C++-like name lookup semantics are used to search for the
+        /// matching descriptor.
+        /// </summary>
+        /// <remarks>
+        /// This isn't heavily optimized, but it's only used during cross linking anyway.
+        /// If it starts being used more widely, we should look at performance more carefully.
+        /// </remarks>
+        internal IDescriptor LookupSymbol(string name, IDescriptor relativeTo)
+        {
+            IDescriptor result;
+            if (name.StartsWith("."))
+            {
+                // Fully-qualified name.
+                result = FindSymbol<IDescriptor>(name.Substring(1));
+            }
+            else
+            {
+                // If "name" is a compound identifier, we want to search for the
+                // first component of it, then search within it for the rest.
+                int firstPartLength = name.IndexOf('.');
+                string firstPart = firstPartLength == -1 ? name : name.Substring(0, firstPartLength);
+
+                // We will search each parent scope of "relativeTo" looking for the
+                // symbol.
+                StringBuilder scopeToTry = new StringBuilder(relativeTo.FullName);
+
+                while (true)
+                {
+                    // Chop off the last component of the scope.
+
+                    int dotpos = scopeToTry.ToString().LastIndexOf(".");
+                    if (dotpos == -1)
+                    {
+                        result = FindSymbol<IDescriptor>(name);
+                        break;
+                    }
+                    else
+                    {
+                        scopeToTry.Length = dotpos + 1;
+
+                        // Append firstPart and try to find.
+                        scopeToTry.Append(firstPart);
+                        result = FindSymbol<IDescriptor>(scopeToTry.ToString());
+
+                        if (result != null)
+                        {
+                            if (firstPartLength != -1)
+                            {
+                                // We only found the first part of the symbol.  Now look for
+                                // the whole thing.  If this fails, we *don't* want to keep
+                                // searching parent scopes.
+                                scopeToTry.Length = dotpos + 1;
+                                scopeToTry.Append(name);
+                                result = FindSymbol<IDescriptor>(scopeToTry.ToString());
+                            }
+                            break;
+                        }
+
+                        // Not found.  Remove the name so we can try again.
+                        scopeToTry.Length = dotpos;
+                    }
+                }
+            }
+
+            if (result == null)
+            {
+                throw new DescriptorValidationException(relativeTo, "\"" + name + "\" is not defined.");
+            }
+            else
+            {
+                return result;
+            }
+        }
+
+        /// <summary>
+        /// Struct used to hold the keys for the fieldByNumber table.
+        /// </summary>
+        private struct DescriptorIntPair : IEquatable<DescriptorIntPair>
+        {
+            private readonly int number;
+            private readonly IDescriptor descriptor;
+
+            internal DescriptorIntPair(IDescriptor descriptor, int number)
+            {
+                this.number = number;
+                this.descriptor = descriptor;
+            }
+
+            public bool Equals(DescriptorIntPair other)
+            {
+                return descriptor == other.descriptor
+                       && number == other.number;
+            }
+
+            public override bool Equals(object obj)
+            {
+                if (obj is DescriptorIntPair)
+                {
+                    return Equals((DescriptorIntPair) obj);
+                }
+                return false;
+            }
+
+            public override int GetHashCode()
+            {
+                return descriptor.GetHashCode()*((1 << 16) - 1) + number;
+            }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/DescriptorUtil.cs

@@ -0,0 +1,64 @@
+#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.Collections.Generic;
+using System.Collections.ObjectModel;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Internal class containing utility methods when working with descriptors.
+    /// </summary>
+    internal static class DescriptorUtil
+    {
+        /// <summary>
+        /// Equivalent to Func[TInput, int, TOutput] but usable in .NET 2.0. Only used to convert
+        /// arrays.
+        /// </summary>
+        internal delegate TOutput IndexedConverter<TInput, TOutput>(TInput element, int index);
+
+        /// <summary>
+        /// Converts the given array into a read-only list, applying the specified conversion to
+        /// each input element.
+        /// </summary>
+        internal static IList<TOutput> ConvertAndMakeReadOnly<TInput, TOutput>
+            (IList<TInput> input, IndexedConverter<TInput, TOutput> converter)
+        {
+            TOutput[] array = new TOutput[input.Count];
+            for (int i = 0; i < array.Length; i++)
+            {
+                array[i] = converter(input[i], i);
+            }
+            return new ReadOnlyCollection<TOutput>(array);
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/DescriptorValidationException.cs

@@ -0,0 +1,80 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Thrown when building descriptors fails because the source DescriptorProtos
+    /// are not valid.
+    /// </summary>
+    public sealed class DescriptorValidationException : Exception
+    {
+        private readonly String name;
+        private readonly string description;
+
+        /// <value>
+        /// The full name of the descriptor where the error occurred.
+        /// </value>
+        public String ProblemSymbolName
+        {
+            get { return name; }
+        }
+
+        /// <value>
+        /// A human-readable description of the error. (The Message property
+        /// is made up of the descriptor's name and this description.)
+        /// </value>
+        public string Description
+        {
+            get { return description; }
+        }
+
+        internal DescriptorValidationException(IDescriptor problemDescriptor, string description) :
+            base(problemDescriptor.FullName + ": " + description)
+        {
+            // Note that problemDescriptor may be partially uninitialized, so we
+            // don't want to expose it directly to the user.  So, we only provide
+            // the name and the original proto.
+            name = problemDescriptor.FullName;
+            this.description = description;
+        }
+
+        internal DescriptorValidationException(IDescriptor problemDescriptor, string description, Exception cause) :
+            base(problemDescriptor.FullName + ": " + description, cause)
+        {
+            name = problemDescriptor.FullName;
+            this.description = description;
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/EnumDescriptor.cs

@@ -0,0 +1,121 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Descriptor for an enum type in a .proto file.
+    /// </summary>
+    public sealed class EnumDescriptor : DescriptorBase
+    {
+        private readonly EnumDescriptorProto proto;
+        private readonly MessageDescriptor containingType;
+        private readonly IList<EnumValueDescriptor> values;
+        private readonly Type clrType;
+
+        internal EnumDescriptor(EnumDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, Type clrType)
+            : base(file, file.ComputeFullName(parent, proto.Name), index)
+        {
+            this.proto = proto;
+            this.clrType = clrType;
+            containingType = parent;
+
+            if (proto.Value.Count == 0)
+            {
+                // We cannot allow enums with no values because this would mean there
+                // would be no valid default value for fields of this type.
+                throw new DescriptorValidationException(this, "Enums must contain at least one value.");
+            }
+
+            values = DescriptorUtil.ConvertAndMakeReadOnly(proto.Value,
+                                                           (value, i) => new EnumValueDescriptor(value, file, this, i));
+
+            File.DescriptorPool.AddSymbol(this);
+        }
+
+        internal EnumDescriptorProto Proto { get { return proto; } }
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name { get { return proto.Name; } }
+
+        /// <summary>
+        /// The CLR type for this enum. For generated code, this will be a CLR enum type.
+        /// </summary>
+        public Type ClrType { get { return clrType; } }
+
+        /// <value>
+        /// If this is a nested type, get the outer descriptor, otherwise null.
+        /// </value>
+        public MessageDescriptor ContainingType
+        {
+            get { return containingType; }
+        }
+
+        /// <value>
+        /// An unmodifiable list of defined value descriptors for this enum.
+        /// </value>
+        public IList<EnumValueDescriptor> Values
+        {
+            get { return values; }
+        }
+
+        /// <summary>
+        /// Finds an enum value by number. If multiple enum values have the
+        /// same number, this returns the first defined value with that number.
+        /// If there is no value for the given number, this returns <c>null</c>.
+        /// </summary>
+        public EnumValueDescriptor FindValueByNumber(int number)
+        {
+            return File.DescriptorPool.FindEnumValueByNumber(this, number);
+        }
+
+        /// <summary>
+        /// Finds an enum value by name.
+        /// </summary>
+        /// <param name="name">The unqualified name of the value (e.g. "FOO").</param>
+        /// <returns>The value's descriptor, or null if not found.</returns>
+        public EnumValueDescriptor FindValueByName(string name)
+        {
+            return File.DescriptorPool.FindSymbol<EnumValueDescriptor>(FullName + "." + name);
+        }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this enum.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+    }
+}

Deps/Source/Google.Protobuf/Reflection/EnumValueDescriptor.cs

@@ -0,0 +1,75 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Descriptor for a single enum value within an enum in a .proto file.
+    /// </summary>
+    public sealed class EnumValueDescriptor : DescriptorBase                                            
+    {
+        private readonly EnumDescriptor enumDescriptor;
+        private readonly EnumValueDescriptorProto proto;
+
+        internal EnumValueDescriptor(EnumValueDescriptorProto proto, FileDescriptor file,
+                                     EnumDescriptor parent, int index)
+            : base(file, parent.FullName + "." + proto.Name, index)
+        {
+            this.proto = proto;
+            enumDescriptor = parent;
+            file.DescriptorPool.AddSymbol(this);
+            file.DescriptorPool.AddEnumValueByNumber(this);
+        }
+
+        internal EnumValueDescriptorProto Proto { get { return proto; } }
+
+        /// <summary>
+        /// Returns the name of the enum value described by this object.
+        /// </summary>
+        public override string Name { get { return proto.Name; } }
+
+        /// <summary>
+        /// Returns the number associated with this enum value.
+        /// </summary>
+        public int Number { get { return Proto.Number; } }
+
+        /// <summary>
+        /// Returns the enum descriptor that this value is part of.
+        /// </summary>
+        public EnumDescriptor EnumDescriptor { get { return enumDescriptor; } }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this enum value.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+    }
+}

Deps/Source/Google.Protobuf/Reflection/FieldAccessorBase.cs

@@ -0,0 +1,62 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Base class for field accessors.
+    /// </summary>
+    internal abstract class FieldAccessorBase : IFieldAccessor
+    {
+        private readonly Func<IMessage, object> getValueDelegate;
+        private readonly FieldDescriptor descriptor;
+
+        internal FieldAccessorBase(PropertyInfo property, FieldDescriptor descriptor)
+        {
+            this.descriptor = descriptor;
+            getValueDelegate = ReflectionUtil.CreateFuncIMessageObject(property.GetGetMethod());
+        }
+
+        public FieldDescriptor Descriptor { get { return descriptor; } }
+
+        public object GetValue(IMessage message)
+        {
+            return getValueDelegate(message);
+        }
+
+        public abstract void Clear(IMessage message);
+        public abstract void SetValue(IMessage message, object value);
+    }
+}

Deps/Source/Google.Protobuf/Reflection/FieldDescriptor.cs

@@ -0,0 +1,347 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Descriptor for a field or extension within a message in a .proto file.
+    /// </summary>
+    public sealed class FieldDescriptor : DescriptorBase, IComparable<FieldDescriptor>
+    {
+        private EnumDescriptor enumType;
+        private MessageDescriptor messageType;
+        private FieldType fieldType;
+        private readonly string propertyName; // Annoyingly, needed in Crosslink.
+        private IFieldAccessor accessor;
+
+        /// <summary>
+        /// Get the field's containing message type.
+        /// </summary>
+        public MessageDescriptor ContainingType { get; }
+
+        /// <summary>
+        /// Returns the oneof containing this field, or <c>null</c> if it is not part of a oneof.
+        /// </summary>
+        public OneofDescriptor ContainingOneof { get; }
+
+        /// <summary>
+        /// The effective JSON name for this field. This is usually the lower-camel-cased form of the field name,
+        /// but can be overridden using the <c>json_name</c> option in the .proto file.
+        /// </summary>
+        public string JsonName { get; }
+
+        internal FieldDescriptorProto Proto { get; }
+
+        internal FieldDescriptor(FieldDescriptorProto proto, FileDescriptor file,
+                                 MessageDescriptor parent, int index, string propertyName)
+            : base(file, file.ComputeFullName(parent, proto.Name), index)
+        {
+            Proto = proto;
+            if (proto.Type != 0)
+            {
+                fieldType = GetFieldTypeFromProtoType(proto.Type);
+            }
+
+            if (FieldNumber <= 0)
+            {
+                throw new DescriptorValidationException(this, "Field numbers must be positive integers.");
+            }
+            ContainingType = parent;
+            // OneofIndex "defaults" to -1 due to a hack in FieldDescriptor.OnConstruction.
+            if (proto.OneofIndex != -1)
+            {
+                if (proto.OneofIndex < 0 || proto.OneofIndex >= parent.Proto.OneofDecl.Count)
+                {
+                    throw new DescriptorValidationException(this,
+                        $"FieldDescriptorProto.oneof_index is out of range for type {parent.Name}");
+                }
+                ContainingOneof = parent.Oneofs[proto.OneofIndex];
+            }
+
+            file.DescriptorPool.AddSymbol(this);
+            // We can't create the accessor until we've cross-linked, unfortunately, as we
+            // may not know whether the type of the field is a map or not. Remember the property name
+            // for later.
+            // We could trust the generated code and check whether the type of the property is
+            // a MapField, but that feels a tad nasty.
+            this.propertyName = propertyName;
+            JsonName =  Proto.JsonName == "" ? JsonFormatter.ToJsonName(Proto.Name) : Proto.JsonName;
+        }
+    
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name => Proto.Name;
+
+        /// <summary>
+        /// Returns the accessor for this field.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// While a <see cref="FieldDescriptor"/> describes the field, it does not provide
+        /// any way of obtaining or changing the value of the field within a specific message;
+        /// that is the responsibility of the accessor.
+        /// </para>
+        /// <para>
+        /// The value returned by this property will be non-null for all regular fields. However,
+        /// if a message containing a map field is introspected, the list of nested messages will include
+        /// an auto-generated nested key/value pair message for the field. This is not represented in any
+        /// generated type, and the value of the map field itself is represented by a dictionary in the
+        /// reflection API. There are never instances of those "hidden" messages, so no accessor is provided
+        /// and this property will return null.
+        /// </para>
+        /// </remarks>
+        public IFieldAccessor Accessor => accessor;
+        
+        /// <summary>
+        /// Maps a field type as included in the .proto file to a FieldType.
+        /// </summary>
+        private static FieldType GetFieldTypeFromProtoType(FieldDescriptorProto.Types.Type type)
+        {
+            switch (type)
+            {
+                case FieldDescriptorProto.Types.Type.Double:
+                    return FieldType.Double;
+                case FieldDescriptorProto.Types.Type.Float:
+                    return FieldType.Float;
+                case FieldDescriptorProto.Types.Type.Int64:
+                    return FieldType.Int64;
+                case FieldDescriptorProto.Types.Type.Uint64:
+                    return FieldType.UInt64;
+                case FieldDescriptorProto.Types.Type.Int32:
+                    return FieldType.Int32;
+                case FieldDescriptorProto.Types.Type.Fixed64:
+                    return FieldType.Fixed64;
+                case FieldDescriptorProto.Types.Type.Fixed32:
+                    return FieldType.Fixed32;
+                case FieldDescriptorProto.Types.Type.Bool:
+                    return FieldType.Bool;
+                case FieldDescriptorProto.Types.Type.String:
+                    return FieldType.String;
+                case FieldDescriptorProto.Types.Type.Group:
+                    return FieldType.Group;
+                case FieldDescriptorProto.Types.Type.Message:
+                    return FieldType.Message;
+                case FieldDescriptorProto.Types.Type.Bytes:
+                    return FieldType.Bytes;
+                case FieldDescriptorProto.Types.Type.Uint32:
+                    return FieldType.UInt32;
+                case FieldDescriptorProto.Types.Type.Enum:
+                    return FieldType.Enum;
+                case FieldDescriptorProto.Types.Type.Sfixed32:
+                    return FieldType.SFixed32;
+                case FieldDescriptorProto.Types.Type.Sfixed64:
+                    return FieldType.SFixed64;
+                case FieldDescriptorProto.Types.Type.Sint32:
+                    return FieldType.SInt32;
+                case FieldDescriptorProto.Types.Type.Sint64:
+                    return FieldType.SInt64;
+                default:
+                    throw new ArgumentException("Invalid type specified");
+            }
+        }
+
+        /// <summary>
+        /// Returns <c>true</c> if this field is a repeated field; <c>false</c> otherwise.
+        /// </summary>
+        public bool IsRepeated => Proto.Label == FieldDescriptorProto.Types.Label.Repeated;
+
+        /// <summary>
+        /// Returns <c>true</c> if this field is a map field; <c>false</c> otherwise.
+        /// </summary>
+        public bool IsMap => fieldType == FieldType.Message && messageType.Proto.Options != null && messageType.Proto.Options.MapEntry;
+
+        /// <summary>
+        /// Returns <c>true</c> if this field is a packed, repeated field; <c>false</c> otherwise.
+        /// </summary>
+        public bool IsPacked => 
+            // Note the || rather than && here - we're effectively defaulting to packed, because that *is*
+            // the default in proto3, which is all we support. We may give the wrong result for the protos
+            // within descriptor.proto, but that's okay, as they're never exposed and we don't use IsPacked
+            // within the runtime.
+            Proto.Options == null || Proto.Options.Packed;
+        
+        /// <summary>
+        /// Returns the type of the field.
+        /// </summary>
+        public FieldType FieldType => fieldType;
+
+        /// <summary>
+        /// Returns the field number declared in the proto file.
+        /// </summary>
+        public int FieldNumber => Proto.Number;
+
+        /// <summary>
+        /// Compares this descriptor with another one, ordering in "canonical" order
+        /// which simply means ascending order by field number. <paramref name="other"/>
+        /// must be a field of the same type, i.e. the <see cref="ContainingType"/> of
+        /// both fields must be the same.
+        /// </summary>
+        public int CompareTo(FieldDescriptor other)
+        {
+            if (other.ContainingType != ContainingType)
+            {
+                throw new ArgumentException("FieldDescriptors can only be compared to other FieldDescriptors " +
+                                            "for fields of the same message type.");
+            }
+            return FieldNumber - other.FieldNumber;
+        }
+
+        /// <summary>
+        /// For enum fields, returns the field's type.
+        /// </summary>
+        public EnumDescriptor EnumType
+        {
+            get
+            {
+                if (fieldType != FieldType.Enum)
+                {
+                    throw new InvalidOperationException("EnumType is only valid for enum fields.");
+                }
+                return enumType;
+            }
+        }
+
+        /// <summary>
+        /// For embedded message and group fields, returns the field's type.
+        /// </summary>
+        public MessageDescriptor MessageType
+        {
+            get
+            {
+                if (fieldType != FieldType.Message)
+                {
+                    throw new InvalidOperationException("MessageType is only valid for message fields.");
+                }
+                return messageType;
+            }
+        }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this field.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+
+        /// <summary>
+        /// Look up and cross-link all field types etc.
+        /// </summary>
+        internal void CrossLink()
+        {
+            if (Proto.TypeName != "")
+            {
+                IDescriptor typeDescriptor =
+                    File.DescriptorPool.LookupSymbol(Proto.TypeName, this);
+
+                if (Proto.Type != 0)
+                {
+                    // Choose field type based on symbol.
+                    if (typeDescriptor is MessageDescriptor)
+                    {
+                        fieldType = FieldType.Message;
+                    }
+                    else if (typeDescriptor is EnumDescriptor)
+                    {
+                        fieldType = FieldType.Enum;
+                    }
+                    else
+                    {
+                        throw new DescriptorValidationException(this, $"\"{Proto.TypeName}\" is not a type.");
+                    }
+                }
+
+                if (fieldType == FieldType.Message)
+                {
+                    if (!(typeDescriptor is MessageDescriptor))
+                    {
+                        throw new DescriptorValidationException(this, $"\"{Proto.TypeName}\" is not a message type.");
+                    }
+                    messageType = (MessageDescriptor) typeDescriptor;
+
+                    if (Proto.DefaultValue != "")
+                    {
+                        throw new DescriptorValidationException(this, "Messages can't have default values.");
+                    }
+                }
+                else if (fieldType == FieldType.Enum)
+                {
+                    if (!(typeDescriptor is EnumDescriptor))
+                    {
+                        throw new DescriptorValidationException(this, $"\"{Proto.TypeName}\" is not an enum type.");
+                    }
+                    enumType = (EnumDescriptor) typeDescriptor;
+                }
+                else
+                {
+                    throw new DescriptorValidationException(this, "Field with primitive type has type_name.");
+                }
+            }
+            else
+            {
+                if (fieldType == FieldType.Message || fieldType == FieldType.Enum)
+                {
+                    throw new DescriptorValidationException(this, "Field with message or enum type missing type_name.");
+                }
+            }
+
+            // Note: no attempt to perform any default value parsing
+
+            File.DescriptorPool.AddFieldByNumber(this);
+
+            if (ContainingType != null && ContainingType.Proto.Options != null && ContainingType.Proto.Options.MessageSetWireFormat)
+            {
+                throw new DescriptorValidationException(this, "MessageSet format is not supported.");
+            }
+            accessor = CreateAccessor();
+        }
+
+        private IFieldAccessor CreateAccessor()
+        {
+            // If we're given no property name, that's because we really don't want an accessor.
+            // (At the moment, that means it's a map entry message...)
+            if (propertyName == null)
+            {
+                return null;
+            }
+            var property = ContainingType.ClrType.GetProperty(propertyName);
+            if (property == null)
+            {
+                throw new DescriptorValidationException(this, $"Property {propertyName} not found in {ContainingType.ClrType}");
+            }
+            return IsMap ? new MapFieldAccessor(property, this)
+                : IsRepeated ? new RepeatedFieldAccessor(property, this)
+                : (IFieldAccessor) new SingleFieldAccessor(property, this);
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/FieldType.cs

@@ -0,0 +1,113 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Enumeration of all the possible field types.
+    /// </summary>
+    public enum FieldType
+    {
+        /// <summary>
+        /// The <c>double</c> field type.
+        /// </summary>
+        Double,
+        /// <summary>
+        /// The <c>float</c> field type.
+        /// </summary>
+        Float,
+        /// <summary>
+        /// The <c>int64</c> field type.
+        /// </summary>
+        Int64,
+        /// <summary>
+        /// The <c>uint64</c> field type.
+        /// </summary>
+        UInt64,
+        /// <summary>
+        /// The <c>int32</c> field type.
+        /// </summary>
+        Int32,
+        /// <summary>
+        /// The <c>fixed64</c> field type.
+        /// </summary>
+        Fixed64,
+        /// <summary>
+        /// The <c>fixed32</c> field type.
+        /// </summary>
+        Fixed32,
+        /// <summary>
+        /// The <c>bool</c> field type.
+        /// </summary>
+        Bool,
+        /// <summary>
+        /// The <c>string</c> field type.
+        /// </summary>
+        String,
+        /// <summary>
+        /// The field type used for groups (not supported in this implementation).
+        /// </summary>
+        Group,
+        /// <summary>
+        /// The field type used for message fields.
+        /// </summary>
+        Message,
+        /// <summary>
+        /// The <c>bytes</c> field type.
+        /// </summary>
+        Bytes,
+        /// <summary>
+        /// The <c>uint32</c> field type.
+        /// </summary>
+        UInt32,
+        /// <summary>
+        /// The <c>sfixed32</c> field type.
+        /// </summary>
+        SFixed32,
+        /// <summary>
+        /// The <c>sfixed64</c> field type.
+        /// </summary>
+        SFixed64,
+        /// <summary>
+        /// The <c>sint32</c> field type.
+        /// </summary>
+        SInt32,
+        /// <summary>
+        /// The <c>sint64</c> field type.
+        /// </summary>
+        SInt64,
+        /// <summary>
+        /// The field type used for enum fields.
+        /// </summary>
+        Enum
+    }
+}

Deps/Source/Google.Protobuf/Reflection/FileDescriptor.cs

@@ -0,0 +1,338 @@
+#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.Collections.ObjectModel;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Describes a .proto file, including everything defined within.
+    /// IDescriptor is implemented such that the File property returns this descriptor,
+    /// and the FullName is the same as the Name.
+    /// </summary>
+    public sealed class FileDescriptor : IDescriptor
+    {
+        private FileDescriptor(ByteString descriptorData, FileDescriptorProto proto, FileDescriptor[] dependencies, DescriptorPool pool, bool allowUnknownDependencies, GeneratedClrTypeInfo generatedCodeInfo)
+        {
+            SerializedData = descriptorData;
+            DescriptorPool = pool;
+            Proto = proto;
+            Dependencies = new ReadOnlyCollection<FileDescriptor>((FileDescriptor[]) dependencies.Clone());
+
+            PublicDependencies = DeterminePublicDependencies(this, proto, dependencies, allowUnknownDependencies);
+
+            pool.AddPackage(Package, this);
+
+            MessageTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.MessageType,
+                                                                 (message, index) =>
+                                                                 new MessageDescriptor(message, this, null, index, generatedCodeInfo.NestedTypes[index]));
+
+            EnumTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.EnumType,
+                                                              (enumType, index) =>
+                                                              new EnumDescriptor(enumType, this, null, index, generatedCodeInfo.NestedEnums[index]));
+
+            Services = DescriptorUtil.ConvertAndMakeReadOnly(proto.Service,
+                                                             (service, index) =>
+                                                             new ServiceDescriptor(service, this, index));
+        }
+
+        /// <summary>
+        /// Computes the full name of a descriptor within this file, with an optional parent message.
+        /// </summary>
+        internal string ComputeFullName(MessageDescriptor parent, string name)
+        {
+            if (parent != null)
+            {
+                return parent.FullName + "." + name;
+            }
+            if (Package.Length > 0)
+            {
+                return Package + "." + name;
+            }
+            return name;
+        }
+
+        /// <summary>
+        /// Extracts public dependencies from direct dependencies. This is a static method despite its
+        /// first parameter, as the value we're in the middle of constructing is only used for exceptions.
+        /// </summary>
+        private static IList<FileDescriptor> DeterminePublicDependencies(FileDescriptor @this, FileDescriptorProto proto, FileDescriptor[] dependencies, bool allowUnknownDependencies)
+        {
+            var nameToFileMap = new Dictionary<string, FileDescriptor>();
+            foreach (var file in dependencies)
+            {
+                nameToFileMap[file.Name] = file;
+            }
+            var publicDependencies = new List<FileDescriptor>();
+            for (int i = 0; i < proto.PublicDependency.Count; i++)
+            {
+                int index = proto.PublicDependency[i];
+                if (index < 0 || index >= proto.Dependency.Count)
+                {
+                    throw new DescriptorValidationException(@this, "Invalid public dependency index.");
+                }
+                string name = proto.Dependency[index];
+                FileDescriptor file = nameToFileMap[name];
+                if (file == null)
+                {
+                    if (!allowUnknownDependencies)
+                    {
+                        throw new DescriptorValidationException(@this, "Invalid public dependency: " + name);
+                    }
+                    // Ignore unknown dependencies.
+                }
+                else
+                {
+                    publicDependencies.Add(file);
+                }
+            }
+            return new ReadOnlyCollection<FileDescriptor>(publicDependencies);
+        }
+
+        /// <value>
+        /// The descriptor in its protocol message representation.
+        /// </value>
+        internal FileDescriptorProto Proto { get; }
+
+        /// <value>
+        /// The file name.
+        /// </value>
+        public string Name => Proto.Name;
+
+        /// <summary>
+        /// The package as declared in the .proto file. This may or may not
+        /// be equivalent to the .NET namespace of the generated classes.
+        /// </summary>
+        public string Package => Proto.Package;
+
+        /// <value>
+        /// Unmodifiable list of top-level message types declared in this file.
+        /// </value>
+        public IList<MessageDescriptor> MessageTypes { get; }
+
+        /// <value>
+        /// Unmodifiable list of top-level enum types declared in this file.
+        /// </value>
+        public IList<EnumDescriptor> EnumTypes { get; }
+
+        /// <value>
+        /// Unmodifiable list of top-level services declared in this file.
+        /// </value>
+        public IList<ServiceDescriptor> Services { get; }
+
+        /// <value>
+        /// Unmodifiable list of this file's dependencies (imports).
+        /// </value>
+        public IList<FileDescriptor> Dependencies { get; }
+
+        /// <value>
+        /// Unmodifiable list of this file's public dependencies (public imports).
+        /// </value>
+        public IList<FileDescriptor> PublicDependencies { get; }
+
+        /// <value>
+        /// The original serialized binary form of this descriptor.
+        /// </value>
+        public ByteString SerializedData { get; }
+
+        /// <value>
+        /// Implementation of IDescriptor.FullName - just returns the same as Name.
+        /// </value>
+        string IDescriptor.FullName => Name;
+
+        /// <value>
+        /// Implementation of IDescriptor.File - just returns this descriptor.
+        /// </value>
+        FileDescriptor IDescriptor.File => this;
+
+        /// <value>
+        /// Pool containing symbol descriptors.
+        /// </value>
+        internal DescriptorPool DescriptorPool { get; }
+
+        /// <summary>
+        /// Finds a type (message, enum, service or extension) in the file by name. Does not find nested types.
+        /// </summary>
+        /// <param name="name">The unqualified type name to look for.</param>
+        /// <typeparam name="T">The type of descriptor to look for</typeparam>
+        /// <returns>The type's descriptor, or null if not found.</returns>
+        public T FindTypeByName<T>(String name)
+            where T : class, IDescriptor
+        {
+            // Don't allow looking up nested types.  This will make optimization
+            // easier later.
+            if (name.IndexOf('.') != -1)
+            {
+                return null;
+            }
+            if (Package.Length > 0)
+            {
+                name = Package + "." + name;
+            }
+            T result = DescriptorPool.FindSymbol<T>(name);
+            if (result != null && result.File == this)
+            {
+                return result;
+            }
+            return null;
+        }
+
+        /// <summary>
+        /// Builds a FileDescriptor from its protocol buffer representation.
+        /// </summary>
+        /// <param name="descriptorData">The original serialized descriptor data.
+        /// We have only limited proto2 support, so serializing FileDescriptorProto
+        /// would not necessarily give us this.</param>
+        /// <param name="proto">The protocol message form of the FileDescriptor.</param>
+        /// <param name="dependencies">FileDescriptors corresponding to all of the
+        /// file's dependencies, in the exact order listed in the .proto file. May be null,
+        /// in which case it is treated as an empty array.</param>
+        /// <param name="allowUnknownDependencies">Whether unknown dependencies are ignored (true) or cause an exception to be thrown (false).</param>
+        /// <param name="generatedCodeInfo">Details about generated code, for the purposes of reflection.</param>
+        /// <exception cref="DescriptorValidationException">If <paramref name="proto"/> is not
+        /// a valid descriptor. This can occur for a number of reasons, such as a field
+        /// having an undefined type or because two messages were defined with the same name.</exception>
+        private static FileDescriptor BuildFrom(ByteString descriptorData, FileDescriptorProto proto, FileDescriptor[] dependencies, bool allowUnknownDependencies, GeneratedClrTypeInfo generatedCodeInfo)
+        {
+            // Building descriptors involves two steps: translating and linking.
+            // In the translation step (implemented by FileDescriptor's
+            // constructor), we build an object tree mirroring the
+            // FileDescriptorProto's tree and put all of the descriptors into the
+            // DescriptorPool's lookup tables.  In the linking step, we look up all
+            // type references in the DescriptorPool, so that, for example, a
+            // FieldDescriptor for an embedded message contains a pointer directly
+            // to the Descriptor for that message's type.  We also detect undefined
+            // types in the linking step.
+            if (dependencies == null)
+            {
+                dependencies = new FileDescriptor[0];
+            }
+
+            DescriptorPool pool = new DescriptorPool(dependencies);
+            FileDescriptor result = new FileDescriptor(descriptorData, proto, dependencies, pool, allowUnknownDependencies, generatedCodeInfo);
+
+            // Validate that the dependencies we've been passed (as FileDescriptors) are actually the ones we
+            // need.
+            if (dependencies.Length != proto.Dependency.Count)
+            {
+                throw new DescriptorValidationException(
+                    result,
+                    "Dependencies passed to FileDescriptor.BuildFrom() don't match " +
+                    "those listed in the FileDescriptorProto.");
+            }
+
+            result.CrossLink();
+            return result;
+        }
+
+        private void CrossLink()
+        {
+            foreach (MessageDescriptor message in MessageTypes)
+            {
+                message.CrossLink();
+            }
+
+            foreach (ServiceDescriptor service in Services)
+            {
+                service.CrossLink();
+            }
+        }
+
+        /// <summary>
+        /// Creates a descriptor for generated code.
+        /// </summary>
+        /// <remarks>
+        /// This method is only designed to be used by the results of generating code with protoc,
+        /// which creates the appropriate dependencies etc. It has to be public because the generated
+        /// code is "external", but should not be called directly by end users.
+        /// </remarks>
+        public static FileDescriptor FromGeneratedCode(
+            byte[] descriptorData,
+            FileDescriptor[] dependencies,
+            GeneratedClrTypeInfo generatedCodeInfo)
+        {
+            FileDescriptorProto proto;
+            try
+            {
+                proto = FileDescriptorProto.Parser.ParseFrom(descriptorData);
+            }
+            catch (InvalidProtocolBufferException e)
+            {
+                throw new ArgumentException("Failed to parse protocol buffer descriptor for generated code.", e);
+            }
+
+            try
+            {
+                // When building descriptors for generated code, we allow unknown
+                // dependencies by default.
+                return BuildFrom(ByteString.CopyFrom(descriptorData), proto, dependencies, true, generatedCodeInfo);
+            }
+            catch (DescriptorValidationException e)
+            {
+                throw new ArgumentException($"Invalid embedded descriptor for \"{proto.Name}\".", e);
+            }
+        }
+
+        /// <summary>
+        /// Returns a <see cref="System.String" /> that represents this instance.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="System.String" /> that represents this instance.
+        /// </returns>
+        public override string ToString()
+        {
+            return $"FileDescriptor for {Name}";
+        }
+
+        /// <summary>
+        /// Returns the file descriptor for descriptor.proto.
+        /// </summary>
+        /// <remarks>
+        /// This is used for protos which take a direct dependency on <c>descriptor.proto</c>, typically for
+        /// annotations. While <c>descriptor.proto</c> is a proto2 file, it is built into the Google.Protobuf
+        /// runtime for reflection purposes. The messages are internal to the runtime as they would require
+        /// proto2 semantics for full support, but the file descriptor is available via this property. The
+        /// C# codegen in protoc automatically uses this property when it detects a dependency on <c>descriptor.proto</c>.
+        /// </remarks>
+        /// <value>
+        /// The file descriptor for <c>descriptor.proto</c>.
+        /// </value>
+        public static FileDescriptor DescriptorProtoFileDescriptor { get { return DescriptorReflection.Descriptor; } }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this file.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+    }
+}

Deps/Source/Google.Protobuf/Reflection/GeneratedClrTypeInfo.cs

@@ -0,0 +1,103 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Extra information provided by generated code when initializing a message or file descriptor.
+    /// These are constructed as required, and are not long-lived. Hand-written code should
+    /// never need to use this type.
+    /// </summary>
+    public sealed class GeneratedClrTypeInfo
+    {
+        private static readonly string[] EmptyNames = new string[0];
+        private static readonly GeneratedClrTypeInfo[] EmptyCodeInfo = new GeneratedClrTypeInfo[0];
+
+        /// <summary>
+        /// Irrelevant for file descriptors; the CLR type for the message for message descriptors.
+        /// </summary>
+        public Type ClrType { get; private set; }
+
+        /// <summary>
+        /// Irrelevant for file descriptors; the parser for message descriptors.
+        /// </summary>
+        public MessageParser Parser { get; }
+
+        /// <summary>
+        /// Irrelevant for file descriptors; the CLR property names (in message descriptor field order)
+        /// for fields in the message for message descriptors.
+        /// </summary>
+        public string[] PropertyNames { get; }
+
+        /// <summary>
+        /// Irrelevant for file descriptors; the CLR property "base" names (in message descriptor oneof order)
+        /// for oneofs in the message for message descriptors. It is expected that for a oneof name of "Foo",
+        /// there will be a "FooCase" property and a "ClearFoo" method.
+        /// </summary>
+        public string[] OneofNames { get; }
+
+        /// <summary>
+        /// The reflection information for types within this file/message descriptor. Elements may be null
+        /// if there is no corresponding generated type, e.g. for map entry types.
+        /// </summary>
+        public GeneratedClrTypeInfo[] NestedTypes { get; }
+
+        /// <summary>
+        /// The CLR types for enums within this file/message descriptor.
+        /// </summary>
+        public Type[] NestedEnums { get; }
+
+        /// <summary>
+        /// Creates a GeneratedClrTypeInfo for a message descriptor, with nested types, nested enums, the CLR type, property names and oneof names.
+        /// Each array parameter may be null, to indicate a lack of values.
+        /// The parameter order is designed to make it feasible to format the generated code readably.
+        /// </summary>
+        public GeneratedClrTypeInfo(Type clrType, MessageParser parser, string[] propertyNames, string[] oneofNames, Type[] nestedEnums, GeneratedClrTypeInfo[] nestedTypes)
+        {
+            NestedTypes = nestedTypes ?? EmptyCodeInfo;
+            NestedEnums = nestedEnums ?? ReflectionUtil.EmptyTypes;
+            ClrType = clrType;
+            Parser = parser;
+            PropertyNames = propertyNames ?? EmptyNames;
+            OneofNames = oneofNames ?? EmptyNames;
+        }
+
+        /// <summary>
+        /// Creates a GeneratedClrTypeInfo for a file descriptor, with only types and enums.
+        /// </summary>
+        public GeneratedClrTypeInfo(Type[] nestedEnums, GeneratedClrTypeInfo[] nestedTypes)
+            : this(null, null, null, null, nestedEnums, nestedTypes)
+        {
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/IDescriptor.cs

@@ -0,0 +1,55 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Interface implemented by all descriptor types.
+    /// </summary>
+    public interface IDescriptor
+    {
+        /// <summary>
+        /// Returns the name of the entity (message, field etc) being described.
+        /// </summary>
+        string Name { get; }
+
+        /// <summary>
+        /// Returns the fully-qualified name of the entity being described.
+        /// </summary>
+        string FullName { get; }
+
+        /// <summary>
+        /// Returns the descriptor for the .proto file that this entity is part of.
+        /// </summary>
+        FileDescriptor File { get; }
+    }    
+}

Deps/Source/Google.Protobuf/Reflection/IFieldAccessor.cs

@@ -0,0 +1,71 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Allows fields to be reflectively accessed.
+    /// </summary>
+    public interface IFieldAccessor
+    {
+        /// <summary>
+        /// Returns the descriptor associated with this field.
+        /// </summary>
+        FieldDescriptor Descriptor { get; }
+
+        /// <summary>
+        /// Clears the field in the specified message. (For repeated fields,
+        /// this clears the list.)
+        /// </summary>
+        void Clear(IMessage message);
+
+        /// <summary>
+        /// Fetches the field value. For repeated values, this will be an
+        /// <see cref="IList"/> implementation. For map values, this will be an
+        /// <see cref="IDictionary"/> implementation.
+        /// </summary>
+        object GetValue(IMessage message);
+
+        /// <summary>
+        /// Mutator for single "simple" fields only.
+        /// </summary>
+        /// <remarks>
+        /// Repeated fields are mutated by fetching the value and manipulating it as a list.
+        /// Map fields are mutated by fetching the value and manipulating it as a dictionary.
+        /// </remarks>
+        /// <exception cref="InvalidOperationException">The field is not a "simple" field.</exception>
+        void SetValue(IMessage message, object value);
+    }
+}

Deps/Source/Google.Protobuf/Reflection/MapFieldAccessor.cs

@@ -0,0 +1,59 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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;
+using System.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Accessor for map fields.
+    /// </summary>
+    internal sealed class MapFieldAccessor : FieldAccessorBase
+    {
+        internal MapFieldAccessor(PropertyInfo property, FieldDescriptor descriptor) : base(property, descriptor)
+        {
+        }
+
+        public override void Clear(IMessage message)
+        {
+            IDictionary list = (IDictionary) GetValue(message);
+            list.Clear();
+        }
+
+        public override void SetValue(IMessage message, object value)
+        {
+            throw new InvalidOperationException("SetValue is not implemented for map fields");
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/MessageDescriptor.cs

@@ -0,0 +1,326 @@
+#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.Collections.ObjectModel;
+using System.Linq;
+#if NET35
+// Needed for ReadOnlyDictionary, which does not exist in .NET 3.5
+using Google.Protobuf.Collections;
+#endif
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Describes a message type.
+    /// </summary>
+    public sealed class MessageDescriptor : DescriptorBase
+    {
+        private static readonly HashSet<string> WellKnownTypeNames = new HashSet<string>
+        {
+            "google/protobuf/any.proto",
+            "google/protobuf/api.proto",
+            "google/protobuf/duration.proto",
+            "google/protobuf/empty.proto",
+            "google/protobuf/wrappers.proto",
+            "google/protobuf/timestamp.proto",
+            "google/protobuf/field_mask.proto",
+            "google/protobuf/source_context.proto",
+            "google/protobuf/struct.proto",
+            "google/protobuf/type.proto",
+        };
+
+        private readonly IList<FieldDescriptor> fieldsInDeclarationOrder;
+        private readonly IList<FieldDescriptor> fieldsInNumberOrder;
+        private readonly IDictionary<string, FieldDescriptor> jsonFieldMap;
+        
+        internal MessageDescriptor(DescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int typeIndex, GeneratedClrTypeInfo generatedCodeInfo)
+            : base(file, file.ComputeFullName(parent, proto.Name), typeIndex)
+        {
+            Proto = proto;
+            Parser = generatedCodeInfo?.Parser;
+            ClrType = generatedCodeInfo?.ClrType;
+            ContainingType = parent;
+
+            // Note use of generatedCodeInfo. rather than generatedCodeInfo?. here... we don't expect
+            // to see any nested oneofs, types or enums in "not actually generated" code... we do
+            // expect fields though (for map entry messages).
+            Oneofs = DescriptorUtil.ConvertAndMakeReadOnly(
+                proto.OneofDecl,
+                (oneof, index) =>
+                new OneofDescriptor(oneof, file, this, index, generatedCodeInfo.OneofNames[index]));
+
+            NestedTypes = DescriptorUtil.ConvertAndMakeReadOnly(
+                proto.NestedType,
+                (type, index) =>
+                new MessageDescriptor(type, file, this, index, generatedCodeInfo.NestedTypes[index]));
+
+            EnumTypes = DescriptorUtil.ConvertAndMakeReadOnly(
+                proto.EnumType,
+                (type, index) =>
+                new EnumDescriptor(type, file, this, index, generatedCodeInfo.NestedEnums[index]));
+
+            fieldsInDeclarationOrder = DescriptorUtil.ConvertAndMakeReadOnly(
+                proto.Field,
+                (field, index) =>
+                new FieldDescriptor(field, file, this, index, generatedCodeInfo?.PropertyNames[index]));
+            fieldsInNumberOrder = new ReadOnlyCollection<FieldDescriptor>(fieldsInDeclarationOrder.OrderBy(field => field.FieldNumber).ToArray());
+            // TODO: Use field => field.Proto.JsonName when we're confident it's appropriate. (And then use it in the formatter, too.)
+            jsonFieldMap = CreateJsonFieldMap(fieldsInNumberOrder);
+            file.DescriptorPool.AddSymbol(this);
+            Fields = new FieldCollection(this);
+        }
+
+        private static ReadOnlyDictionary<string, FieldDescriptor> CreateJsonFieldMap(IList<FieldDescriptor> fields)
+        {
+            var map = new Dictionary<string, FieldDescriptor>();
+            foreach (var field in fields)
+            {
+                map[field.Name] = field;
+                map[field.JsonName] = field;
+            }
+            return new ReadOnlyDictionary<string, FieldDescriptor>(map);
+        }
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name => Proto.Name;
+
+        internal DescriptorProto Proto { get; }
+
+        /// <summary>
+        /// The CLR type used to represent message instances from this descriptor.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// The value returned by this property will be non-null for all regular fields. However,
+        /// if a message containing a map field is introspected, the list of nested messages will include
+        /// an auto-generated nested key/value pair message for the field. This is not represented in any
+        /// generated type, so this property will return null in such cases.
+        /// </para>
+        /// <para>
+        /// For wrapper types (<see cref="Google.Protobuf.WellKnownTypes.StringValue"/> and the like), the type returned here
+        /// will be the generated message type, not the native type used by reflection for fields of those types. Code
+        /// using reflection should call <see cref="IsWrapperType"/> to determine whether a message descriptor represents
+        /// a wrapper type, and handle the result appropriately.
+        /// </para>
+        /// </remarks>
+        public Type ClrType { get; }
+
+        /// <summary>
+        /// A parser for this message type.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// As <see cref="MessageDescriptor"/> is not generic, this cannot be statically
+        /// typed to the relevant type, but it should produce objects of a type compatible with <see cref="ClrType"/>.
+        /// </para>
+        /// <para>
+        /// The value returned by this property will be non-null for all regular fields. However,
+        /// if a message containing a map field is introspected, the list of nested messages will include
+        /// an auto-generated nested key/value pair message for the field. No message parser object is created for
+        /// such messages, so this property will return null in such cases.
+        /// </para>
+        /// <para>
+        /// For wrapper types (<see cref="Google.Protobuf.WellKnownTypes.StringValue"/> and the like), the parser returned here
+        /// will be the generated message type, not the native type used by reflection for fields of those types. Code
+        /// using reflection should call <see cref="IsWrapperType"/> to determine whether a message descriptor represents
+        /// a wrapper type, and handle the result appropriately.
+        /// </para>
+        /// </remarks>
+        public MessageParser Parser { get; }
+
+        /// <summary>
+        /// Returns whether this message is one of the "well known types" which may have runtime/protoc support.
+        /// </summary>
+        internal bool IsWellKnownType => File.Package == "google.protobuf" && WellKnownTypeNames.Contains(File.Name);
+
+        /// <summary>
+        /// Returns whether this message is one of the "wrapper types" used for fields which represent primitive values
+        /// with the addition of presence.
+        /// </summary>
+        internal bool IsWrapperType => File.Package == "google.protobuf" && File.Name == "google/protobuf/wrappers.proto";
+
+        /// <value>
+        /// If this is a nested type, get the outer descriptor, otherwise null.
+        /// </value>
+        public MessageDescriptor ContainingType { get; }
+
+        /// <value>
+        /// A collection of fields, which can be retrieved by name or field number.
+        /// </value>
+        public FieldCollection Fields { get; }
+
+        /// <value>
+        /// An unmodifiable list of this message type's nested types.
+        /// </value>
+        public IList<MessageDescriptor> NestedTypes { get; }
+
+        /// <value>
+        /// An unmodifiable list of this message type's enum types.
+        /// </value>
+        public IList<EnumDescriptor> EnumTypes { get; }
+
+        /// <value>
+        /// An unmodifiable list of the "oneof" field collections in this message type.
+        /// </value>
+        public IList<OneofDescriptor> Oneofs { get; }
+
+        /// <summary>
+        /// Finds a field by field name.
+        /// </summary>
+        /// <param name="name">The unqualified name of the field (e.g. "foo").</param>
+        /// <returns>The field's descriptor, or null if not found.</returns>
+        public FieldDescriptor FindFieldByName(String name) => File.DescriptorPool.FindSymbol<FieldDescriptor>(FullName + "." + name);
+
+        /// <summary>
+        /// Finds a field by field number.
+        /// </summary>
+        /// <param name="number">The field number within this message type.</param>
+        /// <returns>The field's descriptor, or null if not found.</returns>
+        public FieldDescriptor FindFieldByNumber(int number) => File.DescriptorPool.FindFieldByNumber(this, number);
+
+        /// <summary>
+        /// Finds a nested descriptor by name. The is valid for fields, nested
+        /// message types, oneofs and enums.
+        /// </summary>
+        /// <param name="name">The unqualified name of the descriptor, e.g. "Foo"</param>
+        /// <returns>The descriptor, or null if not found.</returns>
+        public T FindDescriptor<T>(string name)  where T : class, IDescriptor =>
+            File.DescriptorPool.FindSymbol<T>(FullName + "." + name);
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this message.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+
+        /// <summary>
+        /// Looks up and cross-links all fields and nested types.
+        /// </summary>
+        internal void CrossLink()
+        {
+            foreach (MessageDescriptor message in NestedTypes)
+            {
+                message.CrossLink();
+            }
+
+            foreach (FieldDescriptor field in fieldsInDeclarationOrder)
+            {
+                field.CrossLink();
+            }
+
+            foreach (OneofDescriptor oneof in Oneofs)
+            {
+                oneof.CrossLink();
+            }
+        }
+
+        /// <summary>
+        /// A collection to simplify retrieving the field accessor for a particular field.
+        /// </summary>
+        public sealed class FieldCollection
+        {
+            private readonly MessageDescriptor messageDescriptor;
+
+            internal FieldCollection(MessageDescriptor messageDescriptor)
+            {
+                this.messageDescriptor = messageDescriptor;
+            }
+
+            /// <value>
+            /// Returns the fields in the message as an immutable list, in the order in which they
+            /// are declared in the source .proto file.
+            /// </value>
+            public IList<FieldDescriptor> InDeclarationOrder() => messageDescriptor.fieldsInDeclarationOrder;
+
+            /// <value>
+            /// Returns the fields in the message as an immutable list, in ascending field number
+            /// order. Field numbers need not be contiguous, so there is no direct mapping from the
+            /// index in the list to the field number; to retrieve a field by field number, it is better
+            /// to use the <see cref="FieldCollection"/> indexer.
+            /// </value>
+            public IList<FieldDescriptor> InFieldNumberOrder() => messageDescriptor.fieldsInNumberOrder;
+
+            // TODO: consider making this public in the future. (Being conservative for now...)
+
+            /// <value>
+            /// Returns a read-only dictionary mapping the field names in this message as they're available
+            /// in the JSON representation to the field descriptors. For example, a field <c>foo_bar</c>
+            /// in the message would result two entries, one with a key <c>fooBar</c> and one with a key
+            /// <c>foo_bar</c>, both referring to the same field.
+            /// </value>
+            internal IDictionary<string, FieldDescriptor> ByJsonName() => messageDescriptor.jsonFieldMap;
+
+            /// <summary>
+            /// Retrieves the descriptor for the field with the given number.
+            /// </summary>
+            /// <param name="number">Number of the field to retrieve the descriptor for</param>
+            /// <returns>The accessor for the given field</returns>
+            /// <exception cref="KeyNotFoundException">The message descriptor does not contain a field
+            /// with the given number</exception>
+            public FieldDescriptor this[int number]
+            {
+                get
+                {
+                    var fieldDescriptor = messageDescriptor.FindFieldByNumber(number);
+                    if (fieldDescriptor == null)
+                    {
+                        throw new KeyNotFoundException("No such field number");
+                    }
+                    return fieldDescriptor;
+                }
+            }
+
+            /// <summary>
+            /// Retrieves the descriptor for the field with the given name.
+            /// </summary>
+            /// <param name="name">Name of the field to retrieve the descriptor for</param>
+            /// <returns>The descriptor for the given field</returns>
+            /// <exception cref="KeyNotFoundException">The message descriptor does not contain a field
+            /// with the given name</exception>
+            public FieldDescriptor this[string name]
+            {
+                get
+                {
+                    var fieldDescriptor = messageDescriptor.FindFieldByName(name);
+                    if (fieldDescriptor == null)
+                    {
+                        throw new KeyNotFoundException("No such field name");
+                    }
+                    return fieldDescriptor;
+                }
+            }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/MethodDescriptor.cs

@@ -0,0 +1,108 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Describes a single method in a service.
+    /// </summary>
+    public sealed class MethodDescriptor : DescriptorBase
+    {
+        private readonly MethodDescriptorProto proto;
+        private readonly ServiceDescriptor service;
+        private MessageDescriptor inputType;
+        private MessageDescriptor outputType;
+
+        /// <value>
+        /// The service this method belongs to.
+        /// </value>
+        public ServiceDescriptor Service { get { return service; } }
+
+        /// <value>
+        /// The method's input type.
+        /// </value>
+        public MessageDescriptor InputType { get { return inputType; } }
+
+        /// <value>
+        /// The method's input type.
+        /// </value>
+        public MessageDescriptor OutputType { get { return outputType; } }
+
+        /// <value>
+        /// Indicates if client streams multiple requests.
+        /// </value>
+        public bool IsClientStreaming { get { return proto.ClientStreaming; } }
+
+        /// <value>
+        /// Indicates if server streams multiple responses.
+        /// </value>
+        public bool IsServerStreaming { get { return proto.ServerStreaming; } }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this method.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+
+        internal MethodDescriptor(MethodDescriptorProto proto, FileDescriptor file,
+                                  ServiceDescriptor parent, int index)
+            : base(file, parent.FullName + "." + proto.Name, index)
+        {
+            this.proto = proto;
+            service = parent;
+            file.DescriptorPool.AddSymbol(this);
+        }
+
+        internal MethodDescriptorProto Proto { get { return proto; } }
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name { get { return proto.Name; } }
+
+        internal void CrossLink()
+        {
+            IDescriptor lookup = File.DescriptorPool.LookupSymbol(Proto.InputType, this);
+            if (!(lookup is MessageDescriptor))
+            {
+                throw new DescriptorValidationException(this, "\"" + Proto.InputType + "\" is not a message type.");
+            }
+            inputType = (MessageDescriptor) lookup;
+
+            lookup = File.DescriptorPool.LookupSymbol(Proto.OutputType, this);
+            if (!(lookup is MessageDescriptor))
+            {
+                throw new DescriptorValidationException(this, "\"" + Proto.OutputType + "\" is not a message type.");
+            }
+            outputType = (MessageDescriptor) lookup;
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/OneofAccessor.cs

@@ -0,0 +1,89 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Reflection access for a oneof, allowing clear and "get case" actions.
+    /// </summary>
+    public sealed class OneofAccessor
+    {
+        private readonly Func<IMessage, int> caseDelegate;
+        private readonly Action<IMessage> clearDelegate;
+        private OneofDescriptor descriptor;
+
+        internal OneofAccessor(PropertyInfo caseProperty, MethodInfo clearMethod, OneofDescriptor descriptor) 
+        {
+            if (!caseProperty.CanRead)
+            {
+                throw new ArgumentException("Cannot read from property");
+            }
+            this.descriptor = descriptor;
+            caseDelegate = ReflectionUtil.CreateFuncIMessageT<int>(caseProperty.GetGetMethod());
+
+            this.descriptor = descriptor;
+            clearDelegate = ReflectionUtil.CreateActionIMessage(clearMethod);
+        }
+
+        /// <summary>
+        /// Gets the descriptor for this oneof.
+        /// </summary>
+        /// <value>
+        /// The descriptor of the oneof.
+        /// </value>
+        public OneofDescriptor Descriptor { get { return descriptor; } }
+
+        /// <summary>
+        /// Clears the oneof in the specified message.
+        /// </summary>
+        public void Clear(IMessage message)
+        {
+            clearDelegate(message);
+        }
+
+        /// <summary>
+        /// Indicates which field in the oneof is set for specified message
+        /// </summary>
+        public FieldDescriptor GetCaseFieldDescriptor(IMessage message)
+        {
+            int fieldNumber = caseDelegate(message);
+            if (fieldNumber > 0)
+            {
+                return descriptor.ContainingType.FindFieldByNumber(fieldNumber);
+            }
+            return null;
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/OneofDescriptor.cs

@@ -0,0 +1,126 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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.Collections.Generic;
+using System.Collections.ObjectModel;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Describes a "oneof" field collection in a message type: a set of
+    /// fields of which at most one can be set in any particular message.
+    /// </summary>
+    public sealed class OneofDescriptor : DescriptorBase
+    {
+        private readonly OneofDescriptorProto proto;
+        private MessageDescriptor containingType;
+        private IList<FieldDescriptor> fields;
+        private readonly OneofAccessor accessor;
+
+        internal OneofDescriptor(OneofDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, string clrName)
+            : base(file, file.ComputeFullName(parent, proto.Name), index)
+        {
+            this.proto = proto;
+            containingType = parent;
+
+            file.DescriptorPool.AddSymbol(this);
+            accessor = CreateAccessor(clrName);
+        }
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name { get { return proto.Name; } }
+
+        /// <summary>
+        /// Gets the message type containing this oneof.
+        /// </summary>
+        /// <value>
+        /// The message type containing this oneof.
+        /// </value>
+        public MessageDescriptor ContainingType
+        {
+            get { return containingType; }
+        }
+
+        /// <summary>
+        /// Gets the fields within this oneof, in declaration order.
+        /// </summary>
+        /// <value>
+        /// The fields within this oneof, in declaration order.
+        /// </value>
+        public IList<FieldDescriptor> Fields { get { return fields; } }
+
+        /// <summary>
+        /// Gets an accessor for reflective access to the values associated with the oneof
+        /// in a particular message.
+        /// </summary>
+        /// <value>
+        /// The accessor used for reflective access.
+        /// </value>
+        public OneofAccessor Accessor { get { return accessor; } }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this oneof.
+        /// </summary>
+        public CustomOptions CustomOptions => proto.Options?.CustomOptions ?? CustomOptions.Empty;
+
+        internal void CrossLink()
+        {
+            List<FieldDescriptor> fieldCollection = new List<FieldDescriptor>();
+            foreach (var field in ContainingType.Fields.InDeclarationOrder())
+            {
+                if (field.ContainingOneof == this)
+                {
+                    fieldCollection.Add(field);
+                }
+            }
+            fields = new ReadOnlyCollection<FieldDescriptor>(fieldCollection);
+        }
+
+        private OneofAccessor CreateAccessor(string clrName)
+        {
+            var caseProperty = containingType.ClrType.GetProperty(clrName + "Case");
+            if (caseProperty == null)
+            {
+                throw new DescriptorValidationException(this, $"Property {clrName}Case not found in {containingType.ClrType}");
+            }
+            var clearMethod = containingType.ClrType.GetMethod("Clear" + clrName);
+            if (clearMethod == null)
+            {
+                throw new DescriptorValidationException(this, $"Method Clear{clrName} not found in {containingType.ClrType}");
+            }
+
+            return new OneofAccessor(caseProperty, clearMethod, this);
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/OriginalNameAttribute.cs

@@ -0,0 +1,65 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Specifies the original name (in the .proto file) of a named element,
+    /// such as an enum value.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Field)]
+    public class OriginalNameAttribute : Attribute
+    {
+        /// <summary>
+        /// The name of the element in the .proto file.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// If the name is preferred in the .proto file.
+        /// </summary>
+        public bool PreferredAlias { get; set; }
+
+        /// <summary>
+        /// Constructs a new attribute instance for the given name.
+        /// </summary>
+        /// <param name="name">The name of the element in the .proto file.</param>
+        public OriginalNameAttribute(string name)
+        {
+            Name = ProtoPreconditions.CheckNotNull(name, nameof(name));
+            PreferredAlias = true;
+        }
+	
+    }
+}

Deps/Source/Google.Protobuf/Reflection/PackageDescriptor.cs

@@ -0,0 +1,68 @@
+#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
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Represents a package in the symbol table.  We use PackageDescriptors
+    /// just as placeholders so that someone cannot define, say, a message type
+    /// that has the same name as an existing package.
+    /// </summary>
+    internal sealed class PackageDescriptor : IDescriptor
+    {
+        private readonly string name;
+        private readonly string fullName;
+        private readonly FileDescriptor file;
+
+        internal PackageDescriptor(string name, string fullName, FileDescriptor file)
+        {
+            this.file = file;
+            this.fullName = fullName;
+            this.name = name;
+        }
+
+        public string Name
+        {
+            get { return name; }
+        }
+
+        public string FullName
+        {
+            get { return fullName; }
+        }
+
+        public FileDescriptor File
+        {
+            get { return file; }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/PartialClasses.cs

@@ -0,0 +1,59 @@
+#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
+
+// This file just contains partial classes for any autogenerated classes that need additional support.
+namespace Google.Protobuf.Reflection
+{
+    internal partial class FieldDescriptorProto
+    {
+        // We can't tell the difference between "explicitly set to 0" and "not set"
+        // in proto3, but we need to tell the difference for OneofIndex. descriptor.proto
+        // is really a proto2 file, but the runtime doesn't know about proto2 semantics...
+        // We fake it by defaulting to -1.
+        partial void OnConstruction()
+        {
+            OneofIndex = -1;
+        }
+    }
+
+    internal partial class FieldOptions
+    {
+        // We can't tell the difference between "explicitly set to false" and "not set"
+        // in proto3, but we need to tell the difference for FieldDescriptor.IsPacked.
+        // This won't work if we ever need to support proto2, but at that point we'll be
+        // able to remove this hack and use field presence instead. 
+        partial void OnConstruction()
+        {
+            Packed = true;
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/ReflectionUtil.cs

@@ -0,0 +1,106 @@
+#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.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();
+        }        
+    }
+}

Deps/Source/Google.Protobuf/Reflection/RepeatedFieldAccessor.cs

@@ -0,0 +1,60 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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;
+using System.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Accessor for repeated fields.
+    /// </summary>
+    internal sealed class RepeatedFieldAccessor : FieldAccessorBase
+    {
+        internal RepeatedFieldAccessor(PropertyInfo property, FieldDescriptor descriptor) : base(property, descriptor)
+        {
+        }
+
+        public override void Clear(IMessage message)
+        {
+            IList list = (IList) GetValue(message);
+            list.Clear();
+        }
+
+        public override void SetValue(IMessage message, object value)
+        {
+            throw new InvalidOperationException("SetValue is not implemented for repeated fields");
+        }
+
+    }
+}

Deps/Source/Google.Protobuf/Reflection/ServiceDescriptor.cs

@@ -0,0 +1,94 @@
+#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;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Describes a service type.
+    /// </summary>
+    public sealed class ServiceDescriptor : DescriptorBase
+    {
+        private readonly ServiceDescriptorProto proto;
+        private readonly IList<MethodDescriptor> methods;
+
+        internal ServiceDescriptor(ServiceDescriptorProto proto, FileDescriptor file, int index)
+            : base(file, file.ComputeFullName(null, proto.Name), index)
+        {
+            this.proto = proto;
+            methods = DescriptorUtil.ConvertAndMakeReadOnly(proto.Method,
+                                                            (method, i) => new MethodDescriptor(method, file, this, i));
+
+            file.DescriptorPool.AddSymbol(this);
+        }
+
+        /// <summary>
+        /// The brief name of the descriptor's target.
+        /// </summary>
+        public override string Name { get { return proto.Name; } }
+
+        internal ServiceDescriptorProto Proto { get { return proto; } }
+
+        /// <value>
+        /// An unmodifiable list of methods in this service.
+        /// </value>
+        public IList<MethodDescriptor> Methods
+        {
+            get { return methods; }
+        }
+
+        /// <summary>
+        /// Finds a method by name.
+        /// </summary>
+        /// <param name="name">The unqualified name of the method (e.g. "Foo").</param>
+        /// <returns>The method's decsriptor, or null if not found.</returns>
+        public MethodDescriptor FindMethodByName(String name)
+        {
+            return File.DescriptorPool.FindSymbol<MethodDescriptor>(FullName + "." + name);
+        }
+
+        /// <summary>
+        /// The (possibly empty) set of custom options for this service.
+        /// </summary>
+        public CustomOptions CustomOptions => Proto.Options?.CustomOptions ?? CustomOptions.Empty;
+
+        internal void CrossLink()
+        {
+            foreach (MethodDescriptor method in methods)
+            {
+                method.CrossLink();
+            }
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/SingleFieldAccessor.cs

@@ -0,0 +1,80 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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.Reflection;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Accessor for single fields.
+    /// </summary>
+    internal sealed class SingleFieldAccessor : FieldAccessorBase
+    {
+        // All the work here is actually done in the constructor - it creates the appropriate delegates.
+        // There are various cases to consider, based on the property type (message, string/bytes, or "genuine" primitive)
+        // and proto2 vs proto3 for non-message types, as proto3 doesn't support "full" presence detection or default
+        // values.
+
+        private readonly Action<IMessage, object> setValueDelegate;
+        private readonly Action<IMessage> clearDelegate;
+
+        internal SingleFieldAccessor(PropertyInfo property, FieldDescriptor descriptor) : base(property, descriptor)
+        {
+            if (!property.CanWrite)
+            {
+                throw new ArgumentException("Not all required properties/methods available");
+            }
+            setValueDelegate = ReflectionUtil.CreateActionIMessageObject(property.GetSetMethod());
+
+            var clrType = property.PropertyType;
+            
+            // TODO: Validate that this is a reasonable single field? (Should be a value type, a message type, or string/ByteString.)
+            object defaultValue =
+                descriptor.FieldType == FieldType.Message ? null
+                : clrType == typeof(string) ? ""
+                : clrType == typeof(ByteString) ? ByteString.Empty
+                : Activator.CreateInstance(clrType);
+            clearDelegate = message => SetValue(message, defaultValue);
+        }
+
+        public override void Clear(IMessage message)
+        {
+            clearDelegate(message);
+        }
+
+        public override void SetValue(IMessage message, object value)
+        {
+            setValueDelegate(message, value);
+        }
+    }
+}

Deps/Source/Google.Protobuf/Reflection/TypeRegistry.cs

@@ -0,0 +1,183 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2015 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.Collections.Generic;
+using System.Linq;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// An immutable registry of types which can be looked up by their full name.
+    /// </summary>
+    public sealed class TypeRegistry
+    {
+        /// <summary>
+        /// An empty type registry, containing no types.
+        /// </summary>
+        public static TypeRegistry Empty { get; } = new TypeRegistry(new Dictionary<string, MessageDescriptor>());
+
+        private readonly Dictionary<string, MessageDescriptor> fullNameToMessageMap;
+
+        private TypeRegistry(Dictionary<string, MessageDescriptor> fullNameToMessageMap)
+        {
+            this.fullNameToMessageMap = fullNameToMessageMap;
+        }
+
+        /// <summary>
+        /// Attempts to find a message descriptor by its full name.
+        /// </summary>
+        /// <param name="fullName">The full name of the message, which is the dot-separated
+        /// combination of package, containing messages and message name</param>
+        /// <returns>The message descriptor corresponding to <paramref name="fullName"/> or null
+        /// if there is no such message descriptor.</returns>
+        public MessageDescriptor Find(string fullName)
+        {
+            MessageDescriptor ret;
+            // Ignore the return value as ret will end up with the right value either way.
+            fullNameToMessageMap.TryGetValue(fullName, out ret);
+            return ret;
+        }
+
+        /// <summary>
+        /// Creates a type registry from the specified set of file descriptors.
+        /// </summary>
+        /// <remarks>
+        /// This is a convenience overload for <see cref="FromFiles(IEnumerable{FileDescriptor})"/>
+        /// to allow calls such as <c>TypeRegistry.FromFiles(descriptor1, descriptor2)</c>.
+        /// </remarks>
+        /// <param name="fileDescriptors">The set of files to include in the registry. Must not contain null values.</param>
+        /// <returns>A type registry for the given files.</returns>
+        public static TypeRegistry FromFiles(params FileDescriptor[] fileDescriptors)
+        {
+            return FromFiles((IEnumerable<FileDescriptor>) fileDescriptors);
+        }
+
+        /// <summary>
+        /// Creates a type registry from the specified set of file descriptors.
+        /// </summary>
+        /// <remarks>
+        /// All message types within all the specified files are added to the registry, and
+        /// the dependencies of the specified files are also added, recursively.
+        /// </remarks>
+        /// <param name="fileDescriptors">The set of files to include in the registry. Must not contain null values.</param>
+        /// <returns>A type registry for the given files.</returns>
+        public static TypeRegistry FromFiles(IEnumerable<FileDescriptor> fileDescriptors)
+        {
+            ProtoPreconditions.CheckNotNull(fileDescriptors, nameof(fileDescriptors));
+            var builder = new Builder();
+            foreach (var file in fileDescriptors)
+            {
+                builder.AddFile(file);
+            }
+            return builder.Build();
+        }
+
+        /// <summary>
+        /// Creates a type registry from the file descriptor parents of the specified set of message descriptors.
+        /// </summary>
+        /// <remarks>
+        /// This is a convenience overload for <see cref="FromMessages(IEnumerable{MessageDescriptor})"/>
+        /// to allow calls such as <c>TypeRegistry.FromFiles(descriptor1, descriptor2)</c>.
+        /// </remarks>
+        /// <param name="messageDescriptors">The set of message descriptors to use to identify file descriptors to include in the registry.
+        /// Must not contain null values.</param>
+        /// <returns>A type registry for the given files.</returns>
+        public static TypeRegistry FromMessages(params MessageDescriptor[] messageDescriptors)
+        {
+            return FromMessages((IEnumerable<MessageDescriptor>) messageDescriptors);
+        }
+
+        /// <summary>
+        /// Creates a type registry from the file descriptor parents of the specified set of message descriptors.
+        /// </summary>
+        /// <remarks>
+        /// The specified message descriptors are only used to identify their file descriptors; the returned registry
+        /// contains all the types within the file descriptors which contain the specified message descriptors (and
+        /// the dependencies of those files), not just the specified messages.
+        /// </remarks>
+        /// <param name="messageDescriptors">The set of message descriptors to use to identify file descriptors to include in the registry.
+        /// Must not contain null values.</param>
+        /// <returns>A type registry for the given files.</returns>
+        public static TypeRegistry FromMessages(IEnumerable<MessageDescriptor> messageDescriptors)
+        {
+            ProtoPreconditions.CheckNotNull(messageDescriptors, nameof(messageDescriptors));
+            return FromFiles(messageDescriptors.Select(md => md.File));
+        }
+
+        /// <summary>
+        /// Builder class which isn't exposed, but acts as a convenient alternative to passing round two dictionaries in recursive calls.
+        /// </summary>
+        private class Builder
+        {
+            private readonly Dictionary<string, MessageDescriptor> types;
+            private readonly HashSet<string> fileDescriptorNames;
+
+            internal Builder()
+            {
+                types = new Dictionary<string, MessageDescriptor>();
+                fileDescriptorNames = new HashSet<string>();
+            }
+
+            internal void AddFile(FileDescriptor fileDescriptor)
+            {
+                if (!fileDescriptorNames.Add(fileDescriptor.Name))
+                {
+                    return;
+                }
+                foreach (var dependency in fileDescriptor.Dependencies)
+                {
+                    AddFile(dependency);
+                }
+                foreach (var message in fileDescriptor.MessageTypes)
+                {
+                    AddMessage(message);
+                }
+            }
+
+            private void AddMessage(MessageDescriptor messageDescriptor)
+            {
+                foreach (var nestedType in messageDescriptor.NestedTypes)
+                {
+                    AddMessage(nestedType);
+                }
+                // This will overwrite any previous entry. Given that each file should
+                // only be added once, this could be a problem such as package A.B with type C,
+                // and package A with type B.C... it's unclear what we should do in that case.
+                types[messageDescriptor.FullName] = messageDescriptor;
+            }
+
+            internal TypeRegistry Build()
+            {
+                return new TypeRegistry(types);
+            }
+        }
+    }
+}