Merge pull request #8433 from genlu/fix8385_

Make `Instance` return 'null' when the referenced member is static

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

@@ -40,7 +40,7 @@ partial class BoundCall : IInvocationExpression
     {
         IMethodSymbol IInvocationExpression.TargetMethod => this.Method;
 
-        IExpression IInvocationExpression.Instance => this.ReceiverOpt;
+        IExpression IInvocationExpression.Instance => this.Method.IsStatic ? null : this.ReceiverOpt;
 
         bool IInvocationExpression.IsVirtual => (this.Method.IsVirtual || this.Method.IsAbstract || this.Method.IsOverride) && !this.ReceiverOpt.SuppressVirtualCalls;
 
@@ -299,7 +299,7 @@ public override void Accept(OperationVisitor visitor)
 
     partial class BoundFieldAccess : IFieldReferenceExpression
     {
-        IExpression IMemberReferenceExpression.Instance => this.ReceiverOpt;
+        IExpression IMemberReferenceExpression.Instance => this.FieldSymbol.IsStatic? null : this.ReceiverOpt;
 
         ISymbol IMemberReferenceExpression.Member => this.FieldSymbol;
 
@@ -322,7 +322,7 @@ partial class BoundPropertyAccess : IPropertyReferenceExpression
     {
         IPropertySymbol IPropertyReferenceExpression.Property => this.PropertySymbol;
        
-        IExpression IMemberReferenceExpression.Instance => this.ReceiverOpt;
+        IExpression IMemberReferenceExpression.Instance => this.PropertySymbol.IsStatic ? null : this.ReceiverOpt;
 
         ISymbol IMemberReferenceExpression.Member => this.PropertySymbol;
 
@@ -343,7 +343,7 @@ partial class BoundEventAccess : IEventReferenceExpression
     {
         IEventSymbol IEventReferenceExpression.Event => this.EventSymbol;
 
-        IExpression IMemberReferenceExpression.Instance => this.ReceiverOpt;
+        IExpression IMemberReferenceExpression.Instance => this.EventSymbol.IsStatic ? null : this.ReceiverOpt;
 
         ISymbol IMemberReferenceExpression.Member => this.EventSymbol;
 
@@ -364,7 +364,7 @@ partial class BoundEventAssignmentOperator : IEventAssignmentExpression
     {
         IEventSymbol IEventAssignmentExpression.Event => this.Event;
 
-        IExpression IEventAssignmentExpression.EventInstance => this.ReceiverOpt;
+        IExpression IEventAssignmentExpression.EventInstance => this.Event.IsStatic ? null : this.ReceiverOpt;
 
         IExpression IEventAssignmentExpression.HandlerValue => this.Argument;
 

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

@@ -4,6 +4,7 @@
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.UnitTests.Diagnostics;
 using Microsoft.CodeAnalysis.UnitTests.Diagnostics.SystemLanguage;
+using Roslyn.Test.Utilities;
 using Xunit;
 
 namespace Microsoft.CodeAnalysis.CSharp.UnitTests
@@ -1277,5 +1278,56 @@ public void OnMumble(System.EventArgs args)
                 Diagnostic(LambdaTestAnalyzer.LambdaExpressionDescriptor.Id, "(s, e) => { int i = 0; i++; i++; i++; }").WithLocation(23, 19),
                 Diagnostic(LambdaTestAnalyzer.TooManyStatementsInLambdaExpressionDescriptor.Id, "(s, e) => { int i = 0; i++; i++; i++; }").WithLocation(23, 19));
         }
+
+        [WorkItem(8385, "https://github.com/dotnet/roslyn/issues/8385")]
+        [Fact]
+        public void StaticMemberReferenceCSharp()
+        {
+            const string source = @"
+using System;
+
+public class D
+{
+    public static event Action E;
+
+    public static int Field;
+
+    public static int Property => 0;
+
+    public static void Method() { }
+}
+
+class C
+{
+    public static event Action E;
+
+    public static void Bar() { }
+
+    void Foo()
+    {
+        C.E += D.Method;
+        C.E();
+        C.Bar();
+
+        D.E += () => { };
+        D.Field = 1;
+        var x = D.Property;
+        D.Method();
+    }
+}
+";
+            CreateCompilationWithMscorlib45(source)
+            .VerifyDiagnostics(Diagnostic(ErrorCode.WRN_UnreferencedEvent, "E").WithArguments("D.E").WithLocation(6, 32))
+            .VerifyAnalyzerDiagnostics(new DiagnosticAnalyzer[] { new StaticMemberTestAnalyzer() }, null, null, false,
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "C.E += D.Method").WithLocation(23, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Method").WithLocation(23, 16),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "C.E").WithLocation(24, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "C.Bar()").WithLocation(25, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.E += () => { }").WithLocation(27, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Field").WithLocation(28, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Property").WithLocation(29, 17),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Method()").WithLocation(30, 9)
+                );
+        }
     }
 }

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

 // Copyright (c) Microsoft Open Technologies, Inc.  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.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis.Diagnostics;
@@ -1219,4 +1220,87 @@ public sealed override void Initialize(AnalysisContext context)
                  OperationKind.LambdaExpression);
         }
     }
+    
+    public class StaticMemberTestAnalyzer : DiagnosticAnalyzer
+    {
+        private const string ReliabilityCategory = "Reliability";
+        
+        public static readonly DiagnosticDescriptor StaticMemberDescriptor = new DiagnosticDescriptor(
+            "StaticMember",
+            "Static member found",
+            "A static member reference expression is found",
+            ReliabilityCategory,
+            DiagnosticSeverity.Warning,
+            isEnabledByDefault: true);
+
+        // We should not see this warning triggered by any code
+        public static readonly DiagnosticDescriptor StaticMemberWithInstanceDescriptor = new DiagnosticDescriptor(
+            "StaticMemberWithInstance",
+            "Static member with non null Instance found",
+            "A static member reference with non null Instance is found",
+            ReliabilityCategory,
+            DiagnosticSeverity.Warning,
+            isEnabledByDefault: true);
+
+        public sealed override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
+        {
+            get { return ImmutableArray.Create(StaticMemberDescriptor,
+                                               StaticMemberWithInstanceDescriptor); }
+        }
+
+        public sealed override void Initialize(AnalysisContext context)
+        {
+            context.RegisterOperationAction(
+                 (operationContext) =>
+                 {
+                     var operation = operationContext.Operation;
+                     ISymbol memberSymbol;
+                     IExpression receiver;
+                     switch (operation.Kind)
+                     {
+                         case OperationKind.FieldReferenceExpression:
+                             memberSymbol = ((IFieldReferenceExpression)operation).Field;
+                             receiver = ((IFieldReferenceExpression)operation).Instance;
+                             break;
+                         case OperationKind.PropertyReferenceExpression:
+                             memberSymbol = ((IPropertyReferenceExpression)operation).Property;
+                             receiver = ((IPropertyReferenceExpression)operation).Instance;
+                             break;
+                         case OperationKind.EventReferenceExpression:
+                             memberSymbol = ((IEventReferenceExpression)operation).Event;
+                             receiver = ((IEventReferenceExpression)operation).Instance;
+                             break;
+                         case OperationKind.MethodBindingExpression:
+                             memberSymbol = ((IMethodBindingExpression)operation).Method;
+                             receiver = ((IMethodBindingExpression)operation).Instance;
+                             break;
+                         case OperationKind.InvocationExpression:
+                             memberSymbol = ((IInvocationExpression)operation).TargetMethod;
+                             receiver = ((IInvocationExpression)operation).Instance;
+                             break;
+                         case OperationKind.EventAssignmentExpression:
+                             memberSymbol = ((IEventAssignmentExpression)operation).Event;
+                             receiver = ((IEventAssignmentExpression)operation).EventInstance;
+                             break;
+                         default:
+                             throw new ArgumentException();
+                     }
+                     if (memberSymbol.IsStatic)
+                     {
+                         operationContext.ReportDiagnostic(Diagnostic.Create(StaticMemberDescriptor, operation.Syntax.GetLocation()));
+
+                         if (receiver != null)
+                         {
+                             operationContext.ReportDiagnostic(Diagnostic.Create(StaticMemberWithInstanceDescriptor, operation.Syntax.GetLocation()));
+                         }
+                     }
+                 },
+                 OperationKind.FieldReferenceExpression,
+                 OperationKind.PropertyReferenceExpression,
+                 OperationKind.EventReferenceExpression,
+                 OperationKind.MethodBindingExpression,
+                 OperationKind.InvocationExpression,
+                 OperationKind.EventAssignmentExpression);
+        }
+    }
 }
\ No newline at end of file

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

@@ -342,7 +342,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IInstance As IExpression Implements IInvocationExpression.Instance
             Get
-                Return Me.ReceiverOpt
+                If Me.Method.IsShared Then
+                    Return Nothing
+                Else
+                    Return Me.ReceiverOpt
+                End If
             End Get
         End Property
 
@@ -1385,7 +1389,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IInstance As IExpression Implements IMemberReferenceExpression.Instance
             Get
-                Return Me.ReceiverOpt
+                If Me.PropertySymbol.IsShared Then
+                    Return Nothing
+                Else
+                    Return Me.ReceiverOpt
+                End If
             End Get
         End Property
 
@@ -1419,7 +1427,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IInstance As IExpression Implements IMemberReferenceExpression.Instance
             Get
-                Return Me.ReceiverOpt
+                If Me.EventSymbol.IsShared Then
+                    Return Nothing
+                Else
+                    Return Me.ReceiverOpt
+                End If
             End Get
         End Property
 
@@ -1453,7 +1465,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IInstance As IExpression Implements IMemberReferenceExpression.Instance
             Get
-                Return Me.ReceiverOpt
+                If Me.Method.IsShared Then
+                    Return Nothing
+                Else
+                    Return Me.ReceiverOpt
+                End If
             End Get
         End Property
 
@@ -1499,7 +1515,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IInstance As IExpression Implements IMemberReferenceExpression.Instance
             Get
-                Return Me.ReceiverOpt
+                If Me.FieldSymbol.IsShared Then
+                    Return Nothing
+                Else
+                    Return Me.ReceiverOpt
+                End If
             End Get
         End Property
 

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

@@ -1442,6 +1442,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
             Public ReadOnly Property EventInstance As IExpression Implements IEventAssignmentExpression.EventInstance
                 Get
+                    If [Event].IsStatic Then
+                        Return Nothing
+                    End If
+
                     Dim eventAccess As BoundEventAccess = TryCast(_statement.EventAccess, BoundEventAccess)
                     If eventAccess IsNot Nothing Then
                         Return eventAccess.ReceiverOpt

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

@@ -4,6 +4,7 @@ Imports System.Collections.Immutable
 Imports Microsoft.CodeAnalysis.Diagnostics
 Imports Microsoft.CodeAnalysis.UnitTests.Diagnostics
 Imports Microsoft.CodeAnalysis.UnitTests.Diagnostics.SystemLanguage
+Imports Roslyn.Test.Utilities
 Imports Xunit
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.UnitTests.Semantics
@@ -1377,5 +1378,57 @@ End Class
                                                      Return value + 1
                                                  End Function").WithLocation(10, 50))
         End Sub
+
+        <WorkItem(8385, "https://github.com/dotnet/roslyn/issues/8385")>
+        <Fact>
+        Public Sub StaticMemberReferenceVisualBasic()
+            Dim source = <compilation>
+                             <file name="c.vb">
+                                 <![CDATA[
+Class D
+    Public Shared Event E()
+
+    Public Shared Field As Integer
+
+    Public Shared Property P As Integer
+
+    Public Shared Sub Method()
+    End Sub
+End Class
+
+Class C
+    Public Shared Event E()
+
+    Public Shared Sub Bar()
+    End Sub
+
+    Public Sub Foo()
+        AddHandler C.E, AddressOf D.Method
+        RaiseEvent E()  ' Can't raise static event with type in VB
+        C.Bar()
+
+        AddHandler D.E, Sub()
+                        End Sub
+        D.Field = 1
+        Dim x = D.P
+        D.Method()
+    End Sub
+End Class
+]]>
+                             </file>
+                         </compilation>
+            Dim comp = CompilationUtils.CreateCompilationWithMscorlibAndVBRuntime(source)
+            comp.VerifyDiagnostics()
+            comp.VerifyAnalyzerDiagnostics({New StaticMemberTestAnalyzer}, Nothing, Nothing, False,
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "AddHandler C.E, AddressOf D.Method").WithLocation(19, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "AddressOf D.Method").WithLocation(19, 25),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "E").WithLocation(20, 20),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "C.Bar()").WithLocation(21, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "AddHandler D.E, Sub()
+                        End Sub").WithLocation(23, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Field").WithLocation(25, 9),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.P").WithLocation(26, 17),
+                Diagnostic(StaticMemberTestAnalyzer.StaticMemberDescriptor.Id, "D.Method()").WithLocation(27, 9))
+        End Sub
     End Class
 End Namespace