Make event reference in raise event statement always explicit

src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory.vb

@@ -1337,15 +1337,20 @@ Namespace Microsoft.CodeAnalysis.Semantics
             Dim eventReferenceSyntax = receiver.Syntax
             Dim eventReferenceType As ITypeSymbol = eventSymbol.Type
             Dim eventReferenceConstantValue As [Optional](Of Object) = ConvertToOptional(receiver.ConstantValueOpt)
-            dim eventReferenceIsImplicit as Boolean = eventInvocation.WasCompilerGenerated
+            ' EventReference in a raise event statement is never implicit. However, the way it is implemented, we don't get
+            ' a "BoundEventAccess" for either field backed event or custom event, and the bound nodes we get are marked as 
+            ' generated by compiler. As a result, we have to explicitly set IsImplicit to false.
+            dim eventReferenceIsImplicit as Boolean = False
             
             Dim boundInstance As BoundNode
             If receiver.Kind = BoundKind.FieldAccess
-                Dim eventFieldAccess = CType(eventInvocation.ReceiverOpt, BoundFieldAccess)
+                ' For raising a field backed event, we will only get a field access node in bound tree.
+                Dim eventFieldAccess = CType(receiver, BoundFieldAccess)
                 Debug.Assert(eventFieldAccess.FieldSymbol.AssociatedSymbol = eventSymbol)
 
                 boundInstance = eventFieldAccess.ReceiverOpt
             Else 
+                ' This is for a custom event
                 boundInstance = receiver
             End If
 

src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IRaiseEventExpression.vb

@@ -26,7 +26,7 @@ End Class]]>.Value
             Dim expectedOperationTree = <![CDATA[
 IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent TestEvent()')
   Event Reference: 
-    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action, IsImplicit) (Syntax: 'TestEvent')
+    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'TestEvent')
       Instance Receiver: 
         IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'TestEvent')
   Arguments(0)
@@ -54,7 +54,7 @@ End Class]]>.Value
             Dim expectedOperationTree = <![CDATA[
 IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent  ... ring.Empty)')
   Event Reference: 
-    IEventReferenceExpression: Event TestClass.MyEvent(x As System.String, y As System.Int32) (OperationKind.EventReferenceExpression, Type: TestClass.MyEventEventHandler, IsImplicit) (Syntax: 'MyEvent')
+    IEventReferenceExpression: Event TestClass.MyEvent(x As System.String, y As System.Int32) (OperationKind.EventReferenceExpression, Type: TestClass.MyEventEventHandler) (Syntax: 'MyEvent')
       Instance Receiver: 
         IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'MyEvent')
   Arguments(2):
@@ -92,7 +92,7 @@ End Class]]>.Value
             Dim expectedOperationTree = <![CDATA[
 IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent TestEvent()')
   Event Reference: 
-    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (Static) (OperationKind.EventReferenceExpression, Type: System.Action, IsImplicit) (Syntax: 'TestEvent')
+    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (Static) (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'TestEvent')
       Instance Receiver: 
         null
   Arguments(0)
@@ -250,7 +250,7 @@ End Class]]>.Value
             Dim expectedOperationTree = <![CDATA[
 IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent TestEvent()')
   Event Reference: 
-    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action, IsImplicit) (Syntax: 'TestEvent')
+    IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'TestEvent')
       Instance Receiver: 
         IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'TestEvent')
   Arguments(0)
@@ -286,7 +286,7 @@ End Class]]>.Value
             Dim expectedOperationTree = <![CDATA[
 IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent  ... g, Nothing)')
   Event Reference: 
-    IEventReferenceExpression: Event TestClass.TestEvent As System.EventHandler (OperationKind.EventReferenceExpression, Type: System.EventHandler, IsImplicit) (Syntax: 'TestEvent')
+    IEventReferenceExpression: Event TestClass.TestEvent As System.EventHandler (OperationKind.EventReferenceExpression, Type: System.EventHandler) (Syntax: 'TestEvent')
       Instance Receiver: 
         IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'TestEvent')
   Arguments(2):
@@ -309,10 +309,33 @@ IRaiseEventStatement (OperationKind.RaiseEventStatement) (Syntax: 'RaiseEvent  .
             Dim expectedDiagnostics = String.Empty
             VerifyOperationTreeAndDiagnosticsForTest(Of RaiseEventStatementSyntax)(source, expectedOperationTree, expectedDiagnostics)
         End Sub
+        
+        <CompilerTrait(CompilerFeature.IOperation)>
+        <Fact>
+        Public Sub EventAccessFromRaiseEventShouldReturnEventReference()
+            Dim source = <![CDATA[
+Imports System
+
+Class TestClass   
+   Event TestEvent As Action
+
+    Sub M()
+        RaiseEvent TestEvent()'BIND:"TestEvent"
+    End Sub
+End Class]]>.Value
+            
+            Dim expectedOperationTree = <![CDATA[
+IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'TestEvent')
+  Instance Receiver: 
+    IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'TestEvent')
+]]>.Value
+            Dim expectedDiagnostics = String.Empty
+            VerifyOperationTreeAndDiagnosticsForTest(Of IdentifierNameSyntax)(source, expectedOperationTree, expectedDiagnostics)
+        End Sub
 
         <CompilerTrait(CompilerFeature.IOperation)>
         <Fact>
-        Public Sub EventAccessFromRaiseCustomEventShouldNotReturnOperation()
+        Public Sub EventAccessFromRaiseCustomEventShouldReturnEventReference()
             Dim source = <![CDATA[
 Imports System
 
@@ -332,9 +355,14 @@ Class TestClass
         RaiseEvent TestEvent()'BIND:"TestEvent"
     End Sub
 End Class]]>.Value
-
+            
+            Dim expectedOperationTree = <![CDATA[
+IEventReferenceExpression: Event TestClass.TestEvent As System.Action (OperationKind.EventReferenceExpression, Type: System.Action) (Syntax: 'TestEvent')
+  Instance Receiver: 
+    IInstanceReferenceExpression (OperationKind.InstanceReferenceExpression, Type: TestClass, IsImplicit) (Syntax: 'TestEvent')
+]]>.Value
             Dim expectedDiagnostics = String.Empty
-            VerifyNoOperationTreeForTest(Of IdentifierNameSyntax)(source)
+            VerifyOperationTreeAndDiagnosticsForTest(Of IdentifierNameSyntax)(source, expectedOperationTree, expectedDiagnostics)
         End Sub
     End Class
 End Namespace