Eliminated ILabeledStatement and OperationKind.LabeledStatement.

src/Compilers/CSharp/Portable/BoundTree/Statement.cs

@@ -642,6 +642,9 @@ public override void Accept(OperationVisitor visitor)
 
     internal partial class BoundLabelStatement : ILabelStatement
     {
+        // These represent synthesized labels, and do not have an attached statement.
+        IOperation ILabelStatement.LabeledStatement => null;
+
         ILabelSymbol ILabelStatement.Label => this.Label;
 
         protected override OperationKind StatementKind => OperationKind.LabelStatement;
@@ -657,22 +660,22 @@ public override void Accept(OperationVisitor visitor)
         }
     }
 
-    internal partial class BoundLabeledStatement : ILabeledStatement
+    internal partial class BoundLabeledStatement : ILabelStatement
     {
-        IOperation ILabeledStatement.Labeled => this.Body;
+        IOperation ILabelStatement.LabeledStatement => this.Body;
 
         ILabelSymbol ILabelStatement.Label => this.Label;
 
-        protected override OperationKind StatementKind => OperationKind.LabeledStatement;
+        protected override OperationKind StatementKind => OperationKind.LabelStatement;
 
         public override void Accept(OperationVisitor visitor)
         {
-            visitor.VisitLabeledStatement(this);
+            visitor.VisitLabelStatement(this);
         }
 
         public override TResult Accept<TArgument, TResult>(OperationVisitor<TArgument, TResult> visitor, TArgument argument)
         {
-            return visitor.VisitLabeledStatement(this, argument);
+            return visitor.VisitLabelStatement(this, argument);
         }
     }
 

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

@@ -1331,6 +1331,29 @@ void Foo()
                 );
         }
 
+        [Fact]
+        public void LabelOperatorsCSharp()
+        {
+            const string source = @"
+public class A
+{
+    public void Fred()
+    {
+        Wilma: goto Betty;
+        Betty: goto Wilma;
+    }
+}
+";
+            CreateCompilationWithMscorlib45(source)
+             .VerifyDiagnostics()
+             .VerifyAnalyzerDiagnostics(new DiagnosticAnalyzer[] { new LabelOperationsTestAnalyzer() }, null, null, false,
+                 Diagnostic(LabelOperationsTestAnalyzer.LabelDescriptor.Id, "Wilma: goto Betty;").WithLocation(6, 9),
+                 Diagnostic(LabelOperationsTestAnalyzer.GotoDescriptor.Id, "goto Betty;").WithLocation(6, 16),
+                 Diagnostic(LabelOperationsTestAnalyzer.LabelDescriptor.Id, "Betty: goto Wilma;").WithLocation(7, 9),
+                 Diagnostic(LabelOperationsTestAnalyzer.GotoDescriptor.Id, "goto Wilma;").WithLocation(7, 16)
+                 );
+        }
+
         [Fact]
         public void UnaryBinaryOperatorsCSharp()
         {

src/Compilers/Core/CodeAnalysisTest/Diagnostics/OperationTestAnalyzer.cs

@@ -1315,6 +1315,56 @@ public sealed override void Initialize(AnalysisContext context)
         }
     }
 
+    public class LabelOperationsTestAnalyzer : DiagnosticAnalyzer
+    {
+        public static readonly DiagnosticDescriptor LabelDescriptor = new DiagnosticDescriptor(
+           "Label",
+           "Label found",
+           "A label was was found",
+           "Testing",
+           DiagnosticSeverity.Warning,
+           isEnabledByDefault: true);
+
+        public static readonly DiagnosticDescriptor GotoDescriptor = new DiagnosticDescriptor(
+          "Goto",
+          "Goto found",
+          "A goto was was found",
+          "Testing",
+          DiagnosticSeverity.Warning,
+          isEnabledByDefault: true);
+
+        public sealed override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(LabelDescriptor, GotoDescriptor);
+
+        public sealed override void Initialize(AnalysisContext context)
+        {
+            context.RegisterOperationAction(
+                (operationContext) =>
+                {
+                    ILabelSymbol label = ((ILabelStatement)operationContext.Operation).Label;
+                    if (label.Name == "Wilma" || label.Name == "Betty")
+                    {
+                        operationContext.ReportDiagnostic(Diagnostic.Create(LabelDescriptor, operationContext.Operation.Syntax.GetLocation()));
+                    }
+                },
+                OperationKind.LabelStatement);
+
+            context.RegisterOperationAction(
+                (operationContext) =>
+                {
+                    IBranchStatement branch = (IBranchStatement)operationContext.Operation;
+                    if (branch.BranchKind == BranchKind.GoTo)
+                    {
+                        ILabelSymbol label = branch.Target;
+                        if (label.Name == "Wilma" || label.Name == "Betty")
+                        {
+                            operationContext.ReportDiagnostic(Diagnostic.Create(GotoDescriptor, branch.Syntax.GetLocation()));
+                        }
+                    }
+                },
+                OperationKind.BranchStatement);
+        }
+    }
+
     public class UnaryAndBinaryOperationsTestAnalyzer : DiagnosticAnalyzer
     {
         public static readonly DiagnosticDescriptor OperatorAddMethodDescriptor = new DiagnosticDescriptor(

src/Compilers/Core/Portable/Compilation/IExpression.cs

@@ -95,19 +95,19 @@ public enum ArgumentKind
         /// <summary>
         /// Argument is specified positionally and matches the parameter of the same ordinality.
         /// </summary>
-        Positional,
+        Positional = 0x0,
         /// <summary>
         /// Argument is specified by name and matches the parameter of the same name.
         /// </summary>
-        Named,
+        Named = 0x1,
         /// <summary>
         /// Argument becomes an element of an array that matches a trailing C# params or VB ParamArray parameter.
         /// </summary>
-        ParamArray,
+        ParamArray = 0x2,
         /// <summary>
         /// Argument was omitted in source but has a default value supplied automatically.
         /// </summary>
-        DefaultValue
+        DefaultValue = 0x3
     }
 
     /// <summary>
@@ -185,16 +185,16 @@ public interface ISyntheticLocalReferenceExpression : IReferenceExpression
     /// </summary>
     public enum SyntheticLocalKind
     {
-        None,
+        None = 0x0,
 
         /// <summary>
         /// Created to capture the step value of a VB for loop.
         /// </summary>
-        ForLoopStepValue,
+        ForLoopStepValue = 0x1,
         /// <summary>
         /// Created to capture the limit value of a VB for loop.
         /// </summary>
-        ForLoopLimitValue
+        ForLoopLimitValue = 0x2
     }
 
     /// <summary>

src/Compilers/Core/Portable/Compilation/IOperation.cs

@@ -50,8 +50,8 @@ public enum OperationKind
         LoopStatement = 0x6,
         /// <summary>Indicates an <see cref="IReturnStatement"/>.</summary>
         YieldBreakStatement = 0x9,
+        /// <summary>Indicates an <see cref="ILabelStatement"/>.</summary>
         LabelStatement = 0xa,
-        LabeledStatement = 0xb,            // Why do both of these exist?
         /// <summary>Indicates an <see cref="IBranchStatement"/>.</summary>
         BranchStatement = 0xc,
         /// <summary>Indicates an <see cref="IEmptyStatement"/>.</summary>

src/Compilers/Core/Portable/Compilation/IStatement.cs

@@ -94,19 +94,19 @@ public enum CaseKind
         /// <summary>
         /// Indicates case x in C# or Case x in VB.
         /// </summary>
-        SingleValue,
+        SingleValue = 0x0,
         /// <summary>
         /// Indicates Case Is op x in VB.
         /// </summary>
-        Relational,
+        Relational = 0x1,
         /// <summary>
         /// Indicates Case x To Y in VB.
         /// </summary>
-        Range,
+        Range = 0x2,
         /// <summary>
         /// Indicates default in C# or Case Else in VB.
         /// </summary>
-        Default
+        Default = 0x3
     }
 
     /// <summary>
@@ -276,17 +276,10 @@ public interface ILabelStatement : IOperation
         ///  Label that can be the target of branches.
         /// </summary>
         ILabelSymbol Label { get; }
-    }
-
-    /// <summary>
-    /// Represents a C# label statement.
-    /// </summary>
-    public interface ILabeledStatement : ILabelStatement
-    {
         /// <summary>
         /// Statement that has been labeled.
         /// </summary>
-        IOperation Labeled { get; }
+        IOperation LabeledStatement { get; }
     }
 
     /// <summary>

src/Compilers/Core/Portable/Compilation/OperationVisitor.cs

@@ -89,12 +89,7 @@ public virtual void VisitLabelStatement(ILabelStatement operation)
         {
             DefaultVisit(operation);
         }
-
-        public virtual void VisitLabeledStatement(ILabeledStatement operation)
-        {
-            DefaultVisit(operation);
-        }
-
+        
         public virtual void VisitBranchStatement(IBranchStatement operation)
         {
             DefaultVisit(operation);
@@ -480,11 +475,6 @@ public virtual TResult VisitLabelStatement(ILabelStatement operation, TArgument
             return DefaultVisit(operation, argument);
         }
 
-        public virtual TResult VisitLabeledStatement(ILabeledStatement operation, TArgument argument)
-        {
-            return DefaultVisit(operation, argument);
-        }
-
         public virtual TResult VisitBranchStatement(IBranchStatement operation, TArgument argument)
         {
             return DefaultVisit(operation, argument);

src/Compilers/Core/Portable/Compilation/OperationWalker.cs

@@ -119,11 +119,8 @@ public override void VisitForEachLoopStatement(IForEachLoopStatement operation)
         }
 
         public override void VisitLabelStatement(ILabelStatement operation)
-        { }
-
-        public override void VisitLabeledStatement(ILabeledStatement operation)
         {
-            Visit(operation.Labeled);
+            Visit(operation.LabeledStatement);
         }
 
         public override void VisitBranchStatement(IBranchStatement operation)

src/Compilers/Core/Portable/PublicAPI.Unshipped.txt

@@ -101,7 +101,6 @@ Microsoft.CodeAnalysis.OperationKind.InvalidStatement = 1 -> Microsoft.CodeAnaly
 Microsoft.CodeAnalysis.OperationKind.InvocationExpression = 28 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.IsExpression = 51 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.LabelStatement = 10 -> Microsoft.CodeAnalysis.OperationKind
-Microsoft.CodeAnalysis.OperationKind.LabeledStatement = 11 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.LambdaExpression = 43 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.LateBoundMemberReferenceExpression = 38 -> Microsoft.CodeAnalysis.OperationKind
 Microsoft.CodeAnalysis.OperationKind.LiteralExpression = 26 -> Microsoft.CodeAnalysis.OperationKind
@@ -434,8 +433,7 @@ Microsoft.CodeAnalysis.Semantics.IIsExpression.IsType.get -> Microsoft.CodeAnaly
 Microsoft.CodeAnalysis.Semantics.IIsExpression.Operand.get -> Microsoft.CodeAnalysis.Semantics.IExpression
 Microsoft.CodeAnalysis.Semantics.ILabelStatement
 Microsoft.CodeAnalysis.Semantics.ILabelStatement.Label.get -> Microsoft.CodeAnalysis.ILabelSymbol
-Microsoft.CodeAnalysis.Semantics.ILabeledStatement
-Microsoft.CodeAnalysis.Semantics.ILabeledStatement.Labeled.get -> Microsoft.CodeAnalysis.IOperation
+Microsoft.CodeAnalysis.Semantics.ILabelStatement.LabeledStatement.get -> Microsoft.CodeAnalysis.IOperation
 Microsoft.CodeAnalysis.Semantics.ILambdaExpression
 Microsoft.CodeAnalysis.Semantics.ILambdaExpression.Body.get -> Microsoft.CodeAnalysis.Semantics.IBlockStatement
 Microsoft.CodeAnalysis.Semantics.ILambdaExpression.Signature.get -> Microsoft.CodeAnalysis.IMethodSymbol
@@ -692,7 +690,6 @@ override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitInvalidStatement(
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitInvocationExpression(Microsoft.CodeAnalysis.Semantics.IInvocationExpression operation) -> void
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitIsExpression(Microsoft.CodeAnalysis.Semantics.IIsExpression operation) -> void
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitLabelStatement(Microsoft.CodeAnalysis.Semantics.ILabelStatement operation) -> void
-override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitLabeledStatement(Microsoft.CodeAnalysis.Semantics.ILabeledStatement operation) -> void
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitLambdaExpression(Microsoft.CodeAnalysis.Semantics.ILambdaExpression operation) -> void
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitLateBoundMemberReferenceExpression(Microsoft.CodeAnalysis.Semantics.ILateBoundMemberReferenceExpression operation) -> void
 override Microsoft.CodeAnalysis.Semantics.OperationWalker.VisitLiteralExpression(Microsoft.CodeAnalysis.Semantics.ILiteralExpression operation) -> void
@@ -785,7 +782,6 @@ virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitInvalidStatement(
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitInvocationExpression(Microsoft.CodeAnalysis.Semantics.IInvocationExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitIsExpression(Microsoft.CodeAnalysis.Semantics.IIsExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitLabelStatement(Microsoft.CodeAnalysis.Semantics.ILabelStatement operation) -> void
-virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitLabeledStatement(Microsoft.CodeAnalysis.Semantics.ILabeledStatement operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitLambdaExpression(Microsoft.CodeAnalysis.Semantics.ILambdaExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitLateBoundMemberReferenceExpression(Microsoft.CodeAnalysis.Semantics.ILateBoundMemberReferenceExpression operation) -> void
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor.VisitLiteralExpression(Microsoft.CodeAnalysis.Semantics.ILiteralExpression operation) -> void
@@ -859,7 +855,6 @@ virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.Vi
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitInvocationExpression(Microsoft.CodeAnalysis.Semantics.IInvocationExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitIsExpression(Microsoft.CodeAnalysis.Semantics.IIsExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitLabelStatement(Microsoft.CodeAnalysis.Semantics.ILabelStatement operation, TArgument argument) -> TResult
-virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitLabeledStatement(Microsoft.CodeAnalysis.Semantics.ILabeledStatement operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitLambdaExpression(Microsoft.CodeAnalysis.Semantics.ILambdaExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitLateBoundMemberReferenceExpression(Microsoft.CodeAnalysis.Semantics.ILateBoundMemberReferenceExpression operation, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.Semantics.OperationVisitor<TArgument, TResult>.VisitLiteralExpression(Microsoft.CodeAnalysis.Semantics.ILiteralExpression operation, TArgument argument) -> TResult

src/Compilers/VisualBasic/Portable/BoundTree/Statement.vb

@@ -1050,6 +1050,13 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
 
+        Private ReadOnly Property ILabeled As IOperation Implements ILabelStatement.LabeledStatement
+            Get
+                ' The VB bound trees do not encode the statement to which the label is attached.
+                Return Nothing
+            End Get
+        End Property
+
         Protected Overrides Function StatementKind() As OperationKind
             Return OperationKind.LabelStatement
         End Function

src/Compilers/VisualBasic/Test/Semantic/Diagnostics/OperationAnalyzerTests.vb

@@ -1432,6 +1432,32 @@ End Class
                 Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Method()").WithLocation(27, 9))
         End Sub
 
+        <Fact>
+        Public Sub LabelOperatorsVisualBasic()
+            Dim source = <compilation>
+                             <file name="c.vb">
+                                 <![CDATA[
+Public Class A
+    Public Sub Fred()
+        Wilma:
+        GoTo Betty
+        Betty:
+        GoTo Wilma
+    End Sub
+End Class
+]]>
+                             </file>
+                         </compilation>
+
+            Dim comp = CompilationUtils.CreateCompilationWithMscorlibAndVBRuntime(source)
+            comp.VerifyDiagnostics()
+            comp.VerifyAnalyzerDiagnostics({New LabelOperationsTestAnalyzer}, Nothing, Nothing, False,
+                Diagnostic(LabelOperationsTestAnalyzer.LabelDescriptor.Id, "Wilma:").WithLocation(3, 9),
+                Diagnostic(LabelOperationsTestAnalyzer.GotoDescriptor.Id, "GoTo Betty").WithLocation(4, 9),
+                Diagnostic(LabelOperationsTestAnalyzer.LabelDescriptor.Id, "Betty:").WithLocation(5, 9),
+                Diagnostic(LabelOperationsTestAnalyzer.GotoDescriptor.Id, "GoTo Wilma").WithLocation(6, 9))
+        End Sub
+
         <Fact>
         Public Sub UnaryBinaryOperatorsVisualBasic()
             Dim source = <compilation>