Report AD0001 if an analyzer accidentally provides a null descriptor in its SupportedDiagnostics

Fixes #30453

src/Compilers/CSharp/Test/Semantic/Diagnostics/DiagnosticAnalyzerTests.cs

@@ -889,6 +889,22 @@ public void TestReportingDiagnosticWithInvalidId()
                      .WithLocation(1, 1));
         }
 
+        [Fact, WorkItem(30453, "https://github.com/dotnet/roslyn/issues/30453")]
+        public void TestAnalyzerWithNullDescriptor()
+        {
+            string source = @"";
+            var analyzers = new DiagnosticAnalyzer[] { new AnalyzerWithNullDescriptor() };
+            var analyzerFullName = "Microsoft.CodeAnalysis.CommonDiagnosticAnalyzers+AnalyzerWithNullDescriptor";
+            string message = new ArgumentException(string.Format(CodeAnalysisResources.SupportedDiagnosticsHasNullDescriptor, analyzerFullName), "SupportedDiagnostics").Message;
+
+            CreateCompilationWithMscorlib45(source)
+                .VerifyDiagnostics()
+                .VerifyAnalyzerDiagnostics(analyzers, null, null, logAnalyzerExceptionAsDiagnostics: true,
+                     expected: Diagnostic("AD0001")
+                     .WithArguments(analyzerFullName, "System.ArgumentException", message)
+                     .WithLocation(1, 1));
+        }
+
         [Fact, WorkItem(25748, "https://github.com/dotnet/roslyn/issues/25748")]
         public void TestReportingDiagnosticWithCSharpCompilerId()
         {

src/Compilers/Core/Portable/CodeAnalysisResources.Designer.cs

@@ -1387,6 +1387,15 @@ internal class CodeAnalysisResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Analyzer &apos;{0}&apos; contains a null descriptor in its &apos;SupportedDiagnostics&apos;..
+        /// </summary>
+        internal static string SupportedDiagnosticsHasNullDescriptor {
+            get {
+                return ResourceManager.GetString("SupportedDiagnosticsHasNullDescriptor", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Windows PDB writer doesn&apos;t support SourceLink feature: &apos;{0}&apos;.
         /// </summary>

src/Compilers/Core/Portable/CodeAnalysisResources.resx

@@ -449,6 +449,9 @@
   <data name="InvalidDiagnosticLocationReported" xml:space="preserve">
     <value>Reported diagnostic '{0}' has a source location in file '{1}', which is not part of the compilation being analyzed.</value>
   </data>
+  <data name="SupportedDiagnosticsHasNullDescriptor" xml:space="preserve">
+    <value>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</value>
+  </data>
   <data name="The_type_0_is_not_understood_by_the_serialization_binder" xml:space="preserve">
     <value>The type '{0}' is not understood by the serialization binder.</value>
   </data>

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalyzerManager.AnalyzerExecutionContext.cs

@@ -260,6 +260,15 @@ public ImmutableArray<DiagnosticDescriptor> GetOrComputeDescriptors(DiagnosticAn
                         var supportedDiagnosticsLocal = analyzer.SupportedDiagnostics;
                         if (!supportedDiagnosticsLocal.IsDefaultOrEmpty)
                         {
+                            foreach (var descriptor in supportedDiagnosticsLocal)
+                            {
+                                if (descriptor == null)
+                                {
+                                    // Disallow null descriptors.
+                                    throw new ArgumentException(string.Format(CodeAnalysisResources.SupportedDiagnosticsHasNullDescriptor, analyzer.ToString()), nameof(DiagnosticAnalyzer.SupportedDiagnostics));
+                                }
+                            }
+
                             supportedDiagnostics = supportedDiagnosticsLocal;
                         }
                     },

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.cs.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Kopie modulu se nedá použít k vytvoření metadat sestavení.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Nevyřešeno: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.de.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Modulkopie kann nicht zum Erstellen von Assembly-Metadaten verwendet werden.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Nicht aufgelöst: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.es.xlf

@@ -59,6 +59,11 @@
         <target state="translated">No se puede usar una copia de módulo para crear metadatos de ensamblado.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Sin resolver: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.fr.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Impossible d'utiliser le module de copie pour créer des métadonnées d'assembly.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Non résolu : </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.it.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Non è possibile usare la copia del modulo per creare i metadati di un assembly.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Non risolto: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ja.xlf

@@ -59,6 +59,11 @@
         <target state="translated">モジュールのコピーは、アセンブリ メタデータの作成には使用できません。</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">未解決: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ko.xlf

@@ -59,6 +59,11 @@
         <target state="translated">모듈 복사본은 어셈블리 메타데이터를 만드는 데 사용할 수 없습니다.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">확인되지 않음: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pl.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Nie można użyć kopii modułu do utworzenia metadanych zestawu.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Nierozpoznane: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pt-BR.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Cópia de módulo não pode ser usada para criar metadados do assembly.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Não resolvido: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ru.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Копию модуля нельзя использовать для создания метаданных сборки.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Не разрешено:</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.tr.xlf

@@ -59,6 +59,11 @@
         <target state="translated">Derleme meta verileri oluşturmak için modül kopyası kullanılamaz.</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">Çözümlenmemiş: </target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hans.xlf

@@ -59,6 +59,11 @@
         <target state="translated">模块复制不能用于创建程序集元数据。</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">未解析:</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hant.xlf

@@ -59,6 +59,11 @@
         <target state="translated">不可使用模組複本建立組件中繼資料。</target>
         <note />
       </trans-unit>
+      <trans-unit id="SupportedDiagnosticsHasNullDescriptor">
+        <source>Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</source>
+        <target state="new">Analyzer '{0}' contains a null descriptor in its 'SupportedDiagnostics'.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="Unresolved">
         <source>Unresolved: </source>
         <target state="translated">未解析: </target>

src/Test/Utilities/Portable/Diagnostics/CommonDiagnosticAnalyzers.cs

@@ -463,6 +463,16 @@ public override void Initialize(AnalysisContext context)
             }
         }
 
+        [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
+        public sealed class AnalyzerWithNullDescriptor : DiagnosticAnalyzer
+        {
+            public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create((DiagnosticDescriptor)null);
+            public override void Initialize(AnalysisContext context)
+            {
+                context.RegisterCompilationAction(_ => { });
+            }
+        }
+
         [DiagnosticAnalyzer(LanguageNames.CSharp, LanguageNames.VisualBasic)]
         public sealed class AnalyzerWithCSharpCompilerDiagnosticId : DiagnosticAnalyzer
         {