1 files changed, 33 insertions, 0 deletions
diff --git a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/Common.cs b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/Common.cs
new file mode 100644
index 0000000000..4867c986e6
--- /dev/null
+++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/Common.cs
@@ -0,0 +1,33 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Godot.SourceGenerators
+{
+    public static class Common
+    {
+        public static void ReportNonPartialGodotScriptClass(
+            GeneratorExecutionContext context,
+            ClassDeclarationSyntax cds, INamedTypeSymbol symbol
+        )
+        {
+            string message =
+                "Missing partial modifier on declaration of type '" +
+                $"{symbol.FullQualifiedName()}' which is a subclass of '{GodotClasses.Object}'";
+
+            string description = $"{message}. Subclasses of '{GodotClasses.Object}' must be " +
+                                 "declared with the partial modifier or annotated with the " +
+                                 $"attribute '{GodotClasses.DisableGodotGeneratorsAttr}'.";
+
+            context.ReportDiagnostic(Diagnostic.Create(
+                new DiagnosticDescriptor(id: "GODOT-G0001",
+                    title: message,
+                    messageFormat: message,
+                    category: "Usage",
+                    DiagnosticSeverity.Error,
+                    isEnabledByDefault: true,
+                    description),
+                cds.GetLocation(),
+                cds.SyntaxTree.FilePath));
+        }
+    }
+}