make CompiledBinding work with x:Static and StaticResource

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs

@@ -15,14 +15,37 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         {
             if (node is XamlAstConstructableObjectNode binding && binding.Type.GetClrType().Equals(context.GetAvaloniaTypes().CompiledBindingExtension))
             {
-                IXamlType startType;
-                var parentDataContextNode = context.ParentNodes().OfType<AvaloniaXamlIlDataContextTypeMetadataNode>().FirstOrDefault();
-                if (parentDataContextNode is null)
+                IXamlType startType = null;
+                var sourceProperty = binding.Children.OfType<XamlPropertyAssignmentNode>().FirstOrDefault(c => c.Property.Name == "Source");
+                if ((sourceProperty?.Values.Count ?? 0) == 1)
                 {
-                    throw new XamlX.XamlParseException("Cannot parse a compiled binding without an explicit x:DataType directive to give a starting data type for bindings.", binding);
+                    var sourceValue = sourceProperty.Values[0];
+                    switch (sourceValue)
+                    {
+                        case XamlAstTextNode textNode:
+                            startType = textNode.Type?.GetClrType();
+                            break;
+
+                        case XamlMarkupExtensionNode extension:
+                            startType = extension.Type?.GetClrType();
+                            break;
+
+                        case XamlStaticExtensionNode staticExtension:
+                            startType = staticExtension.Type?.GetClrType();
+                            break;
+                    }
                 }
 
-                startType = parentDataContextNode.DataContextType;
+                if (startType == null)
+                {
+                    var parentDataContextNode = context.ParentNodes().OfType<AvaloniaXamlIlDataContextTypeMetadataNode>().FirstOrDefault();
+                    if (parentDataContextNode is null)
+                    {
+                        throw new XamlX.XamlParseException("Cannot parse a compiled binding without an explicit x:DataType directive to give a starting data type for bindings.", binding);
+                    }
+
+                    startType = parentDataContextNode.DataContextType;
+                }
 
                 XamlIlBindingPathHelper.UpdateCompiledBindingExtension(context, binding, startType);
             }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlTransformSyntheticCompiledBindingMembers.cs

@@ -27,8 +27,8 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 }
                 else if (prop.Name == "Source")
                 {
-                    return new AvaloniaSyntheticCompiledBindingProperty(node,
-                        SyntheticCompiledBindingPropertyName.Source);
+                    //return new AvaloniaSyntheticCompiledBindingProperty(node,
+                    //    SyntheticCompiledBindingPropertyName.Source);
                 }
             }
 

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindingExtension.cs

@@ -32,6 +32,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
                 Mode = Mode,
                 Priority = Priority,
                 StringFormat = StringFormat,
+                Source = Source,
                 DefaultAnchor = new WeakReference(GetDefaultAnchor(provider))
             };
         }
@@ -52,6 +53,13 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         protected override ExpressionObserver CreateExpressionObserver(IAvaloniaObject target, AvaloniaProperty targetProperty, object anchor, bool enableDataValidation)
         {
+            if (Source != null)
+            {
+                return CreateSourceObserver(
+                    Source,
+                    Path.BuildExpression(enableDataValidation));
+            }
+
             if (Path.RawSource != null)
             {
                 return CreateSourceObserver(
@@ -77,5 +85,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         [ConstructorArgument("path")]
         public CompiledBindingPath Path { get; set; }
+
+        public object Source { get; set; }
     }
 }