First attempt at using profile 259 for Google.Protobuf.

This requires .NET 4.5, and there are a few compatibility changes required around reflection.
Creating a PR from this to see how our CI systems handle it. Will want to add more documentation,
validation and probably tests before merging.

This is in aid of issue #590.

csharp/src/AddressBook/AddressBook.csproj

@@ -10,10 +10,11 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Google.Protobuf.Examples.AddressBook</RootNamespace>
     <AssemblyName>AddressBook</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <StartupObject>Google.Protobuf.Examples.AddressBook.Program</StartupObject>
-    <TargetFrameworkProfile>Client</TargetFrameworkProfile>
+    <TargetFrameworkProfile>
+    </TargetFrameworkProfile>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -26,6 +27,7 @@
     <WarningLevel>4</WarningLevel>
     <NoStdLib>true</NoStdLib>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -37,6 +39,7 @@
     <WarningLevel>4</WarningLevel>
     <NoStdLib>true</NoStdLib>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="mscorlib" />

csharp/src/AddressBook/app.config

 <?xml version="1.0"?>
 <configuration>
-	<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0,Profile=Client"/></startup></configuration>
+	<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/></startup></configuration>

csharp/src/Google.Protobuf.JsonDump/Google.Protobuf.JsonDump.csproj

-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <EnvironmentFlavor>CLIENTPROFILE</EnvironmentFlavor>
@@ -12,9 +12,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Google.Protobuf.JsonDump</RootNamespace>
     <AssemblyName>Google.Protobuf.JsonDump</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
-    <TargetFrameworkProfile>Client</TargetFrameworkProfile>
+    <TargetFrameworkProfile>
+    </TargetFrameworkProfile>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -27,6 +28,7 @@
     <WarningLevel>4</WarningLevel>
     <NoStdLib>true</NoStdLib>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -38,6 +40,7 @@
     <WarningLevel>4</WarningLevel>
     <NoStdLib>true</NoStdLib>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="mscorlib" />

csharp/src/Google.Protobuf.JsonDump/app.config

 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
-<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0,Profile=Client"/></startup></configuration>
+<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/></startup></configuration>

csharp/src/Google.Protobuf/Collections/MapField.cs

@@ -35,6 +35,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Collections
 {
@@ -74,7 +75,7 @@ namespace Google.Protobuf.Collections
         /// <param name="allowNullValues">Whether null values are permitted in the map or not.</param>
         public MapField(bool allowNullValues)
         {
-            if (allowNullValues && typeof(TValue).IsValueType && Nullable.GetUnderlyingType(typeof(TValue)) == null)
+            if (allowNullValues && typeof(TValue).IsValueType() && Nullable.GetUnderlyingType(typeof(TValue)) == null)
             {
                 throw new ArgumentException("allowNullValues", "Non-nullable value types do not support null values");
             }

csharp/src/Google.Protobuf/Collections/RepeatedField.cs

@@ -29,10 +29,12 @@
 // (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 Google.Protobuf.Reflection;
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Collections
 {
@@ -88,7 +90,7 @@ namespace Google.Protobuf.Collections
             uint tag = input.LastTag;
             var reader = codec.ValueReader;
             // Value types can be packed or not.
-            if (typeof(T).IsValueType && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
             {
                 int length = input.ReadLength();
                 if (length > 0)
@@ -119,7 +121,7 @@ namespace Google.Protobuf.Collections
                 return 0;
             }
             uint tag = codec.Tag;
-            if (typeof(T).IsValueType && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
             {
                 int dataSize = CalculatePackedDataSize(codec);
                 return CodedOutputStream.ComputeRawVarint32Size(tag) +
@@ -165,7 +167,7 @@ namespace Google.Protobuf.Collections
             }
             var writer = codec.ValueWriter;
             var tag = codec.Tag;
-            if (typeof(T).IsValueType && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
             {
                 // Packed primitive type
                 uint size = (uint)CalculatePackedDataSize(codec);

csharp/src/Google.Protobuf/Compatibility/PropertyInfoExtensions.cs

+#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.Reflection;
+
+namespace Google.Protobuf.Compatibility
+{
+    internal static class PropertyInfoExtensions
+    {
+        internal static MethodInfo GetGetMethod(this PropertyInfo target)
+        {
+            return target.GetMethod;
+        }
+
+        internal static MethodInfo GetSetMethod(this PropertyInfo target)
+        {
+            return target.SetMethod;
+        }
+    }
+}

csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs

+#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.Compatibility
+{
+    /// <summary>
+    /// Provides extension methods on Type that just proxy to TypeInfo.
+    /// These are used to support the new type system from .NET 4.5, without
+    /// having calls to GetTypeInfo all over the place.
+    /// </summary>
+    internal static class TypeExtensions
+    {
+        internal static bool IsValueType(this Type target)
+        {
+            return target.GetTypeInfo().IsValueType;
+        }
+
+        internal static bool IsAssignableFrom(this Type target, Type c)
+        {
+            return target.GetTypeInfo().IsAssignableFrom(c.GetTypeInfo());
+        }
+
+        internal static PropertyInfo GetProperty(this Type target, string name)
+        {
+            return target.GetTypeInfo().GetDeclaredProperty(name);
+        }
+
+        internal static MethodInfo GetMethod(this Type target, string name)
+        {
+            return target.GetTypeInfo().GetDeclaredMethod(name);
+        }
+    }
+}

csharp/src/Google.Protobuf/Google.Protobuf.csproj

@@ -11,8 +11,8 @@
     <RootNamespace>Google.Protobuf</RootNamespace>
     <AssemblyName>Google.Protobuf</AssemblyName>
     <ProjectTypeGuids>{786C830F-07A1-408B-BD7F-6EE04809D6DB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
-    <TargetFrameworkProfile>Profile92</TargetFrameworkProfile>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkProfile>Profile259</TargetFrameworkProfile>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\..\keys\Google.Protobuf.snk</AssemblyOriginatorKeyFile>
@@ -60,6 +60,8 @@
     <Compile Include="Collections\MapField.cs" />
     <Compile Include="Collections\ReadOnlyDictionary.cs" />
     <Compile Include="Collections\RepeatedField.cs" />
+    <Compile Include="Compatibility\PropertyInfoExtensions.cs" />
+    <Compile Include="Compatibility\TypeExtensions.cs" />
     <Compile Include="FieldCodec.cs" />
     <Compile Include="FrameworkPortability.cs" />
     <Compile Include="Freezable.cs" />
@@ -111,6 +113,7 @@
   <ItemGroup>
     <None Include="Google.Protobuf.nuspec" />
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\Portable\$(TargetFrameworkVersion)\Microsoft.Portable.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

csharp/src/Google.Protobuf/Reflection/FieldAccessorBase.cs

@@ -32,6 +32,7 @@
 
 using System;
 using System.Reflection;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Reflection
 {

csharp/src/Google.Protobuf/Reflection/FieldDescriptor.cs

@@ -32,6 +32,7 @@
 
 using System;
 using System.Linq;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Reflection
 {

csharp/src/Google.Protobuf/Reflection/OneofAccessor.cs

@@ -32,6 +32,7 @@
 
 using System;
 using System.Reflection;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Reflection
 {

csharp/src/Google.Protobuf/Reflection/OneofDescriptor.cs

@@ -33,6 +33,7 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Reflection
 {
@@ -91,7 +92,7 @@ namespace Google.Protobuf.Reflection
             {
                 throw new DescriptorValidationException(this, "Property " + clrName + "Case not found in " + containingType.GeneratedType);
             }
-            var clearMethod = containingType.GeneratedType.GetMethod("Clear" + clrName, ReflectionUtil.EmptyTypes);
+            var clearMethod = containingType.GeneratedType.GetMethod("Clear" + clrName);
             if (clearMethod == null)
             {
                 throw new DescriptorValidationException(this, "Method Clear" + clrName + " not found in " + containingType.GeneratedType);

csharp/src/Google.Protobuf/Reflection/SingleFieldAccessor.cs

@@ -32,6 +32,7 @@
 
 using System;
 using System.Reflection;
+using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Reflection
 {