Disable Cecil backend in runtime compiler based on a property

src/Markup/Avalonia.Markup.Xaml/Avalonia.Markup.Xaml.csproj

@@ -1,7 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <DefineConstants>PCL;NETSTANDARD;NETSTANDARD2_0;HAS_TYPE_CONVERTER;HAS_CUSTOM_ATTRIBUTE_PROVIDER</DefineConstants>
+    <DefineConstants>PCL;NETSTANDARD;NETSTANDARD2_0;HAS_TYPE_CONVERTER;HAS_CUSTOM_ATTRIBUTE_PROVIDER;</DefineConstants>
+    <UseCecil>false</UseCecil>
+    <DefineConstants Condition="$(UseCecil) == true">$(DefineConstants);RUNTIME_XAML_CECIL</DefineConstants>
     <EnableDefaultCompileItems>False</EnableDefaultCompileItems>
     <EnableDefaultItems>false</EnableDefaultItems>
     <NoWarn>CS1591</NoWarn>
@@ -70,7 +72,7 @@
         <Compile Include="XamlLoadException.cs" />
         <Compile Include="PortableXaml\portable.xaml.github\src\Portable.Xaml\**\*.cs" Exclude="PortableXaml\portable.xaml.github\src\Portable.Xaml\Assembly\**\*.cs" />
         <Compile Include="XamlIl\xamlil.github\src\XamlIl\**\*.cs" />
-        <Compile Include="XamlIl\xamlil.github\src\XamlIl.Cecil\**\*.cs" />
+        <Compile Condition="$(UseCecil) == true" Include="XamlIl\xamlil.github\src\XamlIl.Cecil\**\*.cs" />
         <Compile Remove="XamlIl\xamlil.github\**\obj\**\*.cs" />
         <Compile Include="..\Avalonia.Markup\Markup\Parsers\SelectorGrammar.cs" />
     </ItemGroup>
@@ -85,7 +87,7 @@
     <ProjectReference Include="..\..\Avalonia.Styling\Avalonia.Styling.csproj" />
     <ProjectReference Include="..\Avalonia.Markup\Avalonia.Markup.csproj" />
     <PackageReference Include="System.Reflection.Emit" Version="4.3.0" />
-    <PackageReference Include="Mono.Cecil" Version="0.10.3" />
+    <PackageReference Condition="$(UseCecil) == true" Include="Mono.Cecil" Version="0.10.3" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="XamlIl\CompilerExtensions\README.md" />

src/Markup/Avalonia.Markup.Xaml/XamlIl/AvaloniaXamlIlRuntimeCompiler.cs

@@ -9,16 +9,18 @@ using System.Reflection.Emit;
 using System.Runtime.InteropServices;
 using Avalonia.Markup.Xaml.XamlIl.CompilerExtensions;
 using Avalonia.Platform;
-using Mono.Cecil;
-using XamlIl.Ast;
 using XamlIl.Transform;
 using XamlIl.TypeSystem;
+#if RUNTIME_XAML_CECIL
 using TypeAttributes = Mono.Cecil.TypeAttributes;
-
+using Mono.Cecil;
+using XamlIl.Ast;
+#endif
 namespace Avalonia.Markup.Xaml.XamlIl
 {
     public static class AvaloniaXamlIlRuntimeCompiler
     {
+#if !RUNTIME_XAML_CECIL
         private static SreTypeSystem _sreTypeSystem;
         private static ModuleBuilder _sreBuilder;
         private static XamlIlLanguageTypeMappings _sreMappings;
@@ -84,13 +86,6 @@ namespace Avalonia.Markup.Xaml.XamlIl
                 _sreXmlns = XamlIlXmlnsMappings.Resolve(_sreTypeSystem, _sreMappings);
         }
 
-        public static object Load(Stream stream, Assembly localAssembly, object rootInstance, Uri uri)
-        {
-            string xaml;
-            using (var sr = new StreamReader(stream))
-                xaml = sr.ReadToEnd();
-            return LoadCecil(xaml, localAssembly, rootInstance, uri);
-        }
 
         static object LoadSre(string xaml, Assembly localAssembly, object rootInstance, Uri uri)
         {
@@ -107,6 +102,7 @@ namespace Avalonia.Markup.Xaml.XamlIl
                     DumpRuntimeCompilationResults();
             }
         }
+
         
         static object LoadSreCore(string xaml, Assembly localAssembly, object rootInstance, Uri uri)
         {
@@ -130,7 +126,8 @@ namespace Avalonia.Markup.Xaml.XamlIl
 
             return LoadOrPopulate(created, rootInstance);
         }
-
+#endif
+        
         static object LoadOrPopulate(Type created, object rootInstance)
         {
             var isp = Expression.Parameter(typeof(IServiceProvider));
@@ -153,7 +150,20 @@ namespace Avalonia.Markup.Xaml.XamlIl
                 return rootInstance;
             }
         }
+        
+        public static object Load(Stream stream, Assembly localAssembly, object rootInstance, Uri uri)
+        {
+            string xaml;
+            using (var sr = new StreamReader(stream))
+                xaml = sr.ReadToEnd();
+#if RUNTIME_XAML_CECIL
+            return LoadCecil(xaml, localAssembly, rootInstance, uri);
+#else
+            return LoadSre(xaml, localAssembly, rootInstance, uri);
+#endif
+        }
 
+#if RUNTIME_XAML_CECIL
         private static Dictionary<string, (Action<IServiceProvider, object> populate, Func<IServiceProvider, object>
                 build)>
             s_CecilCache =
@@ -232,5 +242,6 @@ namespace Avalonia.Markup.Xaml.XamlIl
             _cecilGeneratedCache[safeUri] = loaded;
             return LoadOrPopulate(loaded, rootInstance);
         }
+#endif
     }
 }