1 files changed, 65 insertions, 0 deletions
diff --git a/modules/mono/glue/GodotSharp/Godot.SourceGenerators.Internal/Common.cs b/modules/mono/glue/GodotSharp/Godot.SourceGenerators.Internal/Common.cs
new file mode 100644
index 0000000000..16e96c725a
--- /dev/null
+++ b/modules/mono/glue/GodotSharp/Godot.SourceGenerators.Internal/Common.cs
@@ -0,0 +1,65 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Godot.SourceGenerators.Internal;
+
+internal static class Common
+{
+    public static void ReportNonPartialUnmanagedCallbacksClass(
+        GeneratorExecutionContext context,
+        ClassDeclarationSyntax cds, INamedTypeSymbol symbol
+    )
+    {
+        string message =
+            "Missing partial modifier on declaration of type '" +
+            $"{symbol.FullQualifiedName()}' which has attribute '{GeneratorClasses.GenerateUnmanagedCallbacksAttr}'";
+
+        string description = $"{message}. Classes with attribute '{GeneratorClasses.GenerateUnmanagedCallbacksAttr}' " +
+                             "must be declared with the partial modifier.";
+
+        context.ReportDiagnostic(Diagnostic.Create(
+            new DiagnosticDescriptor(id: "GODOT-INTERNAL-G0001",
+                title: message,
+                messageFormat: message,
+                category: "Usage",
+                DiagnosticSeverity.Error,
+                isEnabledByDefault: true,
+                description),
+            cds.GetLocation(),
+            cds.SyntaxTree.FilePath));
+    }
+
+    public static void ReportNonPartialUnmanagedCallbacksOuterClass(
+        GeneratorExecutionContext context,
+        TypeDeclarationSyntax outerTypeDeclSyntax
+    )
+    {
+        var outerSymbol = context.Compilation
+            .GetSemanticModel(outerTypeDeclSyntax.SyntaxTree)
+            .GetDeclaredSymbol(outerTypeDeclSyntax);
+
+        string fullQualifiedName = outerSymbol is INamedTypeSymbol namedTypeSymbol ?
+            namedTypeSymbol.FullQualifiedName() :
+            "type not found";
+
+        string message =
+            $"Missing partial modifier on declaration of type '{fullQualifiedName}', " +
+            $"which contains one or more subclasses with attribute " +
+            $"'{GeneratorClasses.GenerateUnmanagedCallbacksAttr}'";
+
+        string description = $"{message}. Classes with attribute " +
+                             $"'{GeneratorClasses.GenerateUnmanagedCallbacksAttr}' and their " +
+                             "containing types must be declared with the partial modifier.";
+
+        context.ReportDiagnostic(Diagnostic.Create(
+            new DiagnosticDescriptor(id: "GODOT-INTERNAL-G0002",
+                title: message,
+                messageFormat: message,
+                category: "Usage",
+                DiagnosticSeverity.Error,
+                isEnabledByDefault: true,
+                description),
+            outerTypeDeclSyntax.GetLocation(),
+            outerTypeDeclSyntax.SyntaxTree.FilePath));
+    }
+}