From d500d5212cc11ae2b7f5d089093fe561ca6d8010 Mon Sep 17 00:00:00 2001
From: Gen Lu <gen.lu@microsoft.com>
Date: Mon, 31 Jul 2017 14:33:28 -0700
Subject: [PATCH] Expose receiver for static event assignemt

---
 .../Operations/CSharpOperationFactory.cs      |  2 +-
 ...erationTests_IEventAssignmentExpression.cs | 43 +++++++++++++++++++
 .../Operations/VisualBasicOperationFactory.vb |  6 +--
 ...erationTests_IEventAssignmentExpression.vb | 34 +++++++++++++++
 4 files changed, 79 insertions(+), 6 deletions(-)

diff --git a/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs b/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
index ba48ce10a90..33fd7d2a4f6 100644
--- a/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
+++ b/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
@@ -365,7 +365,7 @@ private IEventAssignmentExpression CreateBoundEventAssignmentOperatorOperation(B
                 //  2. the constant value of BoundEventAccess is always null.
                 //  3. the syntax of the boundEventAssignmentOperator is always AssignmentExpressionSyntax, so the syntax for the event reference would be the LHS of the assignment.
                 IEventSymbol @event = boundEventAssignmentOperator.Event;
-                Lazy<IOperation> instance = new Lazy<IOperation>(() => Create(boundEventAssignmentOperator.Event.IsStatic ? null : boundEventAssignmentOperator.ReceiverOpt));
+                Lazy<IOperation> instance = new Lazy<IOperation>(() => Create(boundEventAssignmentOperator.ReceiverOpt));
                 SyntaxNode eventAccessSyntax = ((AssignmentExpressionSyntax)syntax).Left;
 
                 return new LazyEventReferenceExpression(@event, instance, @event, eventAccessSyntax, @event.Type, ConvertToOptional(null));
diff --git a/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.cs b/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.cs
index c09a64b2463..ded5831b5f2 100644
--- a/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.cs
+++ b/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.cs
@@ -203,5 +203,48 @@ void M()
 
             VerifyOperationTreeAndDiagnosticsForTest<AssignmentExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
         }
+
+        [Fact]
+        public void AddEventHandler_AssignToStaticEventOnInstance()
+        {
+            string source = @"
+using System;
+
+class Test
+{
+    public static event EventHandler MyEvent;    
+}
+
+class C
+{
+    void Handler(object sender, EventArgs e)
+    {
+    } 
+
+    void M()
+    {
+        var t = new Test();
+        /*<bind>*/t.MyEvent += Handler/*<bind>*/;
+    }
+}
+";
+            string expectedOperationTree = @"
+IEventAssignmentExpression (EventAdd)) (OperationKind.EventAssignmentExpression, Type: System.Void, IsInvalid) (Syntax: 't.MyEvent += Handler')
+  Event Reference: IEventReferenceExpression: event System.EventHandler Test.MyEvent (OperationKind.EventReferenceExpression, Type: System.EventHandler, IsInvalid) (Syntax: 't.MyEvent')
+      Instance Receiver: ILocalReferenceExpression: t (OperationKind.LocalReferenceExpression, Type: Test, IsInvalid) (Syntax: 't')
+  Handler: IMethodBindingExpression: void C.Handler(System.Object sender, System.EventArgs e) (OperationKind.MethodBindingExpression, Type: System.EventHandler) (Syntax: 'Handler')
+      Instance Receiver: IInstanceReferenceExpression (InstanceReferenceKind.Implicit) (OperationKind.InstanceReferenceExpression, Type: C) (Syntax: 'Handler')
+";
+            var expectedDiagnostics = new[] {                  
+                // file.cs(18,19): error CS0176: Member 'Test.MyEvent' cannot be accessed with an instance reference; qualify it with a type name instead
+                //         /*<bind>*/t.MyEvent += Handler/*<bind>*/;
+                Diagnostic(ErrorCode.ERR_ObjectProhibited, "t.MyEvent").WithArguments("Test.MyEvent").WithLocation(18, 19),
+                // file.cs(6,38): warning CS0067: The event 'Test.MyEvent' is never used
+                //     public static event EventHandler MyEvent;
+                Diagnostic(ErrorCode.WRN_UnreferencedEvent, "MyEvent").WithArguments("Test.MyEvent").WithLocation(6, 38)
+            };
+
+            VerifyOperationTreeAndDiagnosticsForTest<AssignmentExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
+        }
     }
 }
diff --git a/src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory.vb b/src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory.vb
index 082d4b415f8..ebc5cd60c9c 100644
--- a/src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory.vb
+++ b/src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory.vb
@@ -574,11 +574,7 @@ Namespace Microsoft.CodeAnalysis.Semantics
         Private Function CreateBoundEventAccessOperation(boundEventAccess As BoundEventAccess) As IEventReferenceExpression
             Dim instance As Lazy(Of IOperation) = New Lazy(Of IOperation)(
                 Function()
-                    If boundEventAccess.EventSymbol.IsShared Then
-                        Return Nothing
-                    Else
-                        Return Create(boundEventAccess.ReceiverOpt)
-                    End If
+                    Return Create(boundEventAccess.ReceiverOpt)
                 End Function)
 
             Dim [event] As IEventSymbol = boundEventAccess.EventSymbol
diff --git a/src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.vb b/src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.vb
index 3ae0ea6ddd0..2b1f9776f1f 100644
--- a/src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.vb
+++ b/src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IEventAssignmentExpression.vb
@@ -169,5 +169,39 @@ BC31143: Method 'Public Sub M(x As Integer)' does not have a signature compatibl
             VerifyOperationTreeAndDiagnosticsForTest(Of AddRemoveHandlerStatementSyntax)(source, expectedOperationTree, expectedDiagnostics)
         End Sub
 
+        <Fact>
+        Public Sub AddEventHandler_AssignToSharedEventOnInstance()
+            Dim source = <![CDATA[
+Imports System
+
+Class TestClass
+
+    Shared Event TestEvent As Action
+
+    Sub Remove()
+        AddHandler Me.TestEvent, AddressOf M 'BIND:"AddHandler Me.TestEvent, AddressOf M"
+    End Sub
+
+    Sub M()
+    End Sub
+End Class]]>.Value
+            Dim expectedOperationTree = <![CDATA[
+IExpressionStatement (OperationKind.ExpressionStatement) (Syntax: 'AddHandler  ... AddressOf M')
+  Expression: IEventAssignmentExpression (EventAdd)) (OperationKind.EventAssignmentExpression, Type: null) (Syntax: 'AddHandler  ... AddressOf M')
+      Event Reference: IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'Me.TestEvent')
+          Instance Receiver: IInstanceReferenceExpression (InstanceReferenceKind.Explicit) (OperationKind.InstanceReferenceExpression, Type: TestClass) (Syntax: 'Me')
+      Handler: IOperation:  (OperationKind.None) (Syntax: 'AddressOf M')
+          Children(1):
+              IInstanceReferenceExpression (InstanceReferenceKind.Implicit) (OperationKind.InstanceReferenceExpression, Type: TestClass) (Syntax: 'M')
+]]>.Value
+
+            Dim expectedDiagnostics = <![CDATA[
+BC42025: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
+        AddHandler Me.TestEvent, AddressOf M 'BIND:"AddHandler Me.TestEvent, AddressOf M"
+                   ~~~~~~~~~~~~
+]]>.Value
+            VerifyOperationTreeAndDiagnosticsForTest(Of AddRemoveHandlerStatementSyntax)(source, expectedOperationTree, expectedDiagnostics)
+        End Sub
+
     End Class
 End Namespace
-- 
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