Merge pull request #40833 from 333fred/annotate-binder

Annotate Binder.cs and BuckStopsHereBinder

src/Compilers/CSharp/Portable/Binder/Binder_Expressions.cs

@@ -90,7 +90,7 @@ protected bool InCrefButNotParameterOrReturnType
         /// </summary>
         protected virtual bool IsUnboundTypeAllowed(GenericNameSyntax syntax)
         {
-            return _next.IsUnboundTypeAllowed(syntax);
+            return Next.IsUnboundTypeAllowed(syntax);
         }
 
         /// <summary>

src/Compilers/CSharp/Portable/Binder/Binder_Statements.cs

@@ -29,7 +29,7 @@ internal partial class Binder
         /// </remarks>
         internal virtual ImmutableHashSet<Symbol> LockedOrDisposedVariables
         {
-            get { return _next.LockedOrDisposedVariables; }
+            get { return Next.LockedOrDisposedVariables; }
         }
 
         /// <remarks>

src/Compilers/CSharp/Portable/Binder/BuckStopsHereBinder.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+#nullable enable
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Roslyn.Utilities;
@@ -12,14 +12,14 @@ namespace Microsoft.CodeAnalysis.CSharp
     /// <summary>
     /// A binder that knows no symbols and will not delegate further.
     /// </summary>
-    internal partial class BuckStopsHereBinder : Binder
+    internal class BuckStopsHereBinder : Binder
     {
         internal BuckStopsHereBinder(CSharpCompilation compilation)
             : base(compilation)
         {
         }
 
-        internal override ImportChain ImportChain
+        internal override ImportChain? ImportChain
         {
             get
             {
@@ -44,12 +44,12 @@ internal override Imports GetImports(ConsList<TypeSymbol> basesBeingResolved)
             return Imports.Empty;
         }
 
-        protected override SourceLocalSymbol LookupLocal(SyntaxToken nameToken)
+        protected override SourceLocalSymbol? LookupLocal(SyntaxToken nameToken)
         {
             return null;
         }
 
-        protected override LocalFunctionSymbol LookupLocalFunction(SyntaxToken nameToken)
+        protected override LocalFunctionSymbol? LookupLocalFunction(SyntaxToken nameToken)
         {
             return null;
         }
@@ -80,7 +80,7 @@ internal override ConsList<FieldSymbol> FieldsBeingBound
             }
         }
 
-        internal override LocalSymbol LocalInProgress
+        internal override LocalSymbol? LocalInProgress
         {
             get
             {
@@ -117,7 +117,7 @@ internal override bool IsIndirectlyInIterator
             }
         }
 
-        internal override GeneratedLabelSymbol BreakLabel
+        internal override GeneratedLabelSymbol? BreakLabel
         {
             get
             {
@@ -125,7 +125,7 @@ internal override GeneratedLabelSymbol BreakLabel
             }
         }
 
-        internal override GeneratedLabelSymbol ContinueLabel
+        internal override GeneratedLabelSymbol? ContinueLabel
         {
             get
             {
@@ -133,7 +133,7 @@ internal override GeneratedLabelSymbol ContinueLabel
             }
         }
 
-        internal override BoundExpression ConditionalReceiverExpression
+        internal override BoundExpression? ConditionalReceiverExpression
         {
             get
             {
@@ -149,7 +149,7 @@ internal override TypeWithAnnotations GetIteratorElementType()
             throw ExceptionUtilities.Unreachable;
         }
 
-        internal override Symbol ContainingMemberOrLambda
+        internal override Symbol? ContainingMemberOrLambda
         {
             get
             {
@@ -174,7 +174,7 @@ internal override bool AreNullableAnnotationsGloballyEnabled()
             }
         }
 
-        internal override Binder GetBinder(SyntaxNode node)
+        internal override Binder? GetBinder(SyntaxNode node)
         {
             return null;
         }

src/Compilers/CSharp/Portable/Symbols/AliasSymbol.cs

@@ -235,7 +235,7 @@ public override Accessibility DeclaredAccessibility
         /// return that as the "containing" symbol, even though the alias isn't a member of the
         /// namespace as such.
         /// </summary>
-        public override Symbol ContainingSymbol
+        public override Symbol? ContainingSymbol
         {
             get
             {

src/Compilers/CSharp/Portable/Symbols/Tuples/TupleTypeSymbol.cs

@@ -250,7 +250,7 @@ private static NamedTypeSymbol ConstructTupleUnderlyingType(NamedTypeSymbol firs
             return currentSymbol;
         }
 
-        private static void ReportUseSiteAndObsoleteDiagnostics(CSharpSyntaxNode? syntax, DiagnosticBag? diagnostics, NamedTypeSymbol firstTupleType)
+        private static void ReportUseSiteAndObsoleteDiagnostics(CSharpSyntaxNode? syntax, DiagnosticBag diagnostics, NamedTypeSymbol firstTupleType)
         {
             Binder.ReportUseSiteDiagnostics(firstTupleType, diagnostics, syntax);
             Binder.ReportDiagnosticsIfObsoleteInternal(diagnostics, firstTupleType, syntax, firstTupleType.ContainingType, BinderFlags.None);
@@ -259,7 +259,7 @@ private static void ReportUseSiteAndObsoleteDiagnostics(CSharpSyntaxNode? syntax
         /// <summary>
         /// For tuples with no natural type, we still need to verify that an underlying type of proper arity exists, and report if otherwise.
         /// </summary>
-        internal static void VerifyTupleTypePresent(int cardinality, CSharpSyntaxNode? syntax, CSharpCompilation compilation, DiagnosticBag? diagnostics)
+        internal static void VerifyTupleTypePresent(int cardinality, CSharpSyntaxNode? syntax, CSharpCompilation compilation, DiagnosticBag diagnostics)
         {
             Debug.Assert(diagnostics is object && syntax is object);