From c312107737a7369e59aff9f7fdfc33bae0d85d3e Mon Sep 17 00:00:00 2001
From: hadashiA <dev@hadashikick.jp>
Date: Tue, 1 Oct 2024 09:28:50 +0900
Subject: [PATCH] Add diagnostic descriptr

---
 VContainer.SourceGenerator/DiagnosticDescriptors.cs | 8 ++++++++
 VContainer.SourceGenerator/Emitter.cs               | 4 ++++
 2 files changed, 12 insertions(+)

diff --git a/VContainer.SourceGenerator/DiagnosticDescriptors.cs b/VContainer.SourceGenerator/DiagnosticDescriptors.cs
index c5bbd8ac..6e772a48 100644
--- a/VContainer.SourceGenerator/DiagnosticDescriptors.cs
+++ b/VContainer.SourceGenerator/DiagnosticDescriptors.cs
@@ -85,5 +85,13 @@ static class DiagnosticDescriptors
             category: Category,
             defaultSeverity: DiagnosticSeverity.Warning,
             isEnabledByDefault: true);
+
+        public static readonly DiagnosticDescriptor ConstructorNotFound = new(
+            id: "VCON0011",
+            title: "The any callbale constructor is not found. Cannot support to code generation.",
+            messageFormat: "Cannot find any constructor of '{0}' that can be called from internal. It cannot support source generator.",
+            category: Category,
+            defaultSeverity: DiagnosticSeverity.Warning,
+            isEnabledByDefault: true);
     }
 }
diff --git a/VContainer.SourceGenerator/Emitter.cs b/VContainer.SourceGenerator/Emitter.cs
index b885681f..da810017 100644
--- a/VContainer.SourceGenerator/Emitter.cs
+++ b/VContainer.SourceGenerator/Emitter.cs
@@ -250,6 +250,10 @@ public static bool TryEmitCreateInstanceMethod(
 
         if (constructorSymbol == null)
         {
+            context.ReportDiagnostic(Diagnostic.Create(
+                DiagnosticDescriptors.ConstructorNotFound,
+                typeMeta.GetLocation(),
+                typeMeta.TypeName));
             return false;
         }