[XamlC] compile NullExtension markup (#750)

2 files changed, 19 insertions, 0 deletions

diff --git a/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/NullExtension.cs b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/NullExtension.cs
new file mode 100644
index 00000000..6701dacc
--- /dev/null
+++ b/Xamarin.Forms.Build.Tasks/CompiledMarkupExtensions/NullExtension.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using Xamarin.Forms.Xaml;
+
+namespace Xamarin.Forms.Build.Tasks
+{
+	class NullExtension : ICompiledMarkupExtension
+	{
+
+		public IEnumerable<Instruction> ProvideValue(IElementNode node, ModuleDefinition module, ILContext context, out TypeReference typeRef)
+		{
+			typeRef = module.TypeSystem.Object;
+			return new[] { Instruction.Create(OpCodes.Ldnull) };
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
index 0175a4b8..880fa0c3 100644
--- a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
+++ b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
@@ -111,6 +111,7 @@
     <Compile Include="CompiledValueProviders\PassthroughValueProvider.cs" />
     <Compile Include="CompiledConverters\ListStringTypeConverter.cs" />
     <Compile Include="CompiledMarkupExtensions\TypeExtension.cs" />
+    <Compile Include="CompiledMarkupExtensions\NullExtension.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Target Name="AfterBuild">