Add some more missing nullable annotations found after building the e…

…ntire solution

src/Microsoft.CodeQuality.Analyzers/Core/ApiDesignGuidelines/EnumWithFlagsAttribute.Fixer.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Collections.Immutable;
 using System.Composition;
-using System.Diagnostics;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;

src/Microsoft.CodeQuality.Analyzers/Core/ApiDesignGuidelines/ImplementStandardExceptionConstructors.cs

@@ -130,7 +130,7 @@ private void AnalyzeCompilationSymbol(CompilationStartAnalysisContext context)
         private static void ReportDiagnostic(SymbolAnalysisContext context, INamedTypeSymbol namedTypeSymbol, MissingCtorSignature missingCtorSignature, string constructorSignature)
         {
             //store MissingCtorSignature enum type into dictionary, to set diagnostic property. This is needed because Diagnostic is immutable
-            ImmutableDictionary<string, string>.Builder builder = ImmutableDictionary.CreateBuilder<string, string>();
+            ImmutableDictionary<string, string?>.Builder builder = ImmutableDictionary.CreateBuilder<string, string?>();
             builder.Add("Signature", missingCtorSignature.ToString());
 
             //create dignostic and store signature into diagnostic property for fixer

src/Microsoft.CodeQuality.Analyzers/Core/ApiDesignGuidelines/UseGenericEventHandlerInstances.cs

@@ -2,7 +2,6 @@
 
 using System;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Linq;
 using Analyzer.Utilities;
 using Analyzer.Utilities.Extensions;

src/Microsoft.CodeQuality.Analyzers/Core/Maintainability/UseNameofInPlaceOfString.Fixer.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;

src/Microsoft.CodeQuality.Analyzers/VisualBasic/QualityGuidelines/BasicRemoveEmptyFinalizersAnalyzer.vb

@@ -1,4 +1,5 @@
-Imports Analyzer.Utilities
+' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
 Imports Analyzer.Utilities.Extensions
 Imports Microsoft.CodeAnalysis
 Imports Microsoft.CodeAnalysis.Diagnostics

src/Microsoft.NetCore.Analyzers/CSharp/Performance/CSharpUsePropertyInsteadOfCountMethodWhenAvailable.cs

@@ -42,7 +42,7 @@ internal CSharpOperationActionsHandler(OperationActionsContext context)
             {
             }
 
-            protected override ITypeSymbol GetEnumerableCountInvocationTargetType(IInvocationOperation invocationOperation)
+            protected override ITypeSymbol? GetEnumerableCountInvocationTargetType(IInvocationOperation invocationOperation)
             {
                 var method = invocationOperation.TargetMethod;
 

src/Microsoft.NetCore.Analyzers/CSharp/Runtime/CSharpMarkAllNonSerializableFields.Fixer.cs

@@ -11,7 +11,7 @@ namespace Microsoft.NetCore.CSharp.Analyzers.Runtime
     [ExportCodeFixProvider(LanguageNames.CSharp, Name = "CA2237 CodeFix provider"), Shared]
     public class CSharpMarkAllNonSerializableFieldsFixer : MarkAllNonSerializableFieldsFixer
     {
-        protected override SyntaxNode GetFieldDeclarationNode(SyntaxNode node)
+        protected override SyntaxNode? GetFieldDeclarationNode(SyntaxNode node)
         {
             SyntaxNode fieldNode = node;
             while (fieldNode != null && fieldNode.Kind() != SyntaxKind.FieldDeclaration)

src/Microsoft.NetCore.Analyzers/CSharp/Runtime/CSharpUseOrdinalStringComparison.cs

@@ -16,7 +16,7 @@ protected override Location GetMethodNameLocation(SyntaxNode invocationNode)
         {
             Debug.Assert(invocationNode.IsKind(SyntaxKind.InvocationExpression));
 
-            var invocation = invocationNode as InvocationExpressionSyntax;
+            var invocation = (InvocationExpressionSyntax)invocationNode;
             if (invocation.Expression.IsKind(SyntaxKind.SimpleMemberAccessExpression))
             {
                 return ((MemberAccessExpressionSyntax)invocation.Expression).Name.GetLocation();

src/Microsoft.NetCore.Analyzers/Core/Performance/UsePropertyInsteadOfCountMethodWhenAvailable.cs

@@ -291,7 +291,7 @@ internal void AnalyzeInvocationOperation(OperationAnalysisContext context)
             /// </summary>
             /// <param name="invocationOperation">The invocation operation.</param>
             /// <returns>The <see cref="ITypeSymbol"/> of the receiver of the extension method.</returns>
-            protected abstract ITypeSymbol GetEnumerableCountInvocationTargetType(IInvocationOperation invocationOperation);
+            protected abstract ITypeSymbol? GetEnumerableCountInvocationTargetType(IInvocationOperation invocationOperation);
 
             /// <summary>
             /// Gets the replacement property.

src/Microsoft.NetCore.Analyzers/Core/Runtime/MarkAllNonSerializableFields.Fixer.cs

@@ -20,13 +20,13 @@ public abstract class MarkAllNonSerializableFieldsFixer : CodeFixProvider
     {
         public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(SerializationRulesDiagnosticAnalyzer.RuleCA2235Id);
 
-        protected abstract SyntaxNode GetFieldDeclarationNode(SyntaxNode node);
+        protected abstract SyntaxNode? GetFieldDeclarationNode(SyntaxNode node);
 
         public override async Task RegisterCodeFixesAsync(CodeFixContext context)
         {
             SyntaxNode root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
             SyntaxNode node = root.FindNode(context.Span);
-            SyntaxNode fieldNode = GetFieldDeclarationNode(node);
+            SyntaxNode? fieldNode = GetFieldDeclarationNode(node);
             if (fieldNode == null)
             {
                 return;

src/Roslyn.Diagnostics.Analyzers/CSharp/CSharpSpecializedEnumerableCreationAnalyzer.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;

src/Tools/ReleaseNotesUtil/RuleFileContent.cs

@@ -7,6 +7,6 @@ namespace ReleaseNotesUtil
     internal class RuleFileContent
     {
         [DataMember]
-        public List<RuleInfo> Rules { get; set; }
+        public List<RuleInfo>? Rules { get; set; }
     }
 }

src/Utilities/Compiler/CodeMetrics/ComputationalComplexityMetrics.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Operations;

src/Utilities/Compiler/Extensions/CompilationExtensions.cs

@@ -1,5 +1,6 @@
-using System.Diagnostics.CodeAnalysis;
-using System.Linq;
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.CodeAnalysis;
 
 namespace Analyzer.Utilities.Extensions

src/Utilities/FlowAnalysis/FlowAnalysis/Analysis/CopyAnalysis/CopyAnalysis.CoreCopyAnalysisDataDomain.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 
 namespace Microsoft.CodeAnalysis.FlowAnalysis.DataFlow.CopyAnalysis
 {

src/Utilities/FlowAnalysis/FlowAnalysis/Analysis/PropertySetAnalysis/PropertySetAnalysis.PropertySetAbstractValueDomain.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 using Analyzer.Utilities.PooledObjects;
 using Microsoft.CodeAnalysis.FlowAnalysis.DataFlow;
 

src/Utilities/FlowAnalysis/FlowAnalysis/Framework/DataFlow/AbstractIndex.OperationBasedIndex.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
 
 namespace Microsoft.CodeAnalysis.FlowAnalysis.DataFlow
 {