Check accessor before associated symbol

src/Compilers/CSharp/Test/Emit/Attributes/AttributeTests_WellKnownAttributes.cs

@@ -6510,40 +6510,101 @@ internal sealed class C1 : I1
         [Fact]
         public void TestObsoleteAndPropertyAccessors()
         {
-            var source =
+            var source0 =
 @"using System;
-[Obsolete] class A { }
-[Obsolete] class B { }
-class C
+namespace Windows.Foundation.Metadata
+{
+    public sealed class DeprecatedAttribute : Attribute
+    {
+        public DeprecatedAttribute(System.String message, DeprecationType type, System.UInt32 version)
+        {
+        }
+    }
+    public enum DeprecationType
+    {
+        Deprecate = 0,
+        Remove = 1
+    }
+}";
+            var source1 =
+@"using Windows.Foundation.Metadata;
+[Deprecated(null, DeprecationType.Deprecate, 0)] class A { }
+[Deprecated(null, DeprecationType.Deprecate, 0)] class B { }
+[Deprecated(null, DeprecationType.Deprecate, 0)] class C { }
+class D
 {
     object P { get { return new A(); } }
-    [Obsolete] object Q { get { return new B(); } }
+    [Deprecated(null, DeprecationType.Deprecate, 0)] object Q { get { return new B(); } }
+    object R { [Deprecated(null, DeprecationType.Deprecate, 0)] get { return new C(); } }
 }";
-            var comp = CreateCompilationWithMscorlibAndSystemCore(source);
+            var comp = CreateStandardCompilation(new[] { Parse(source0), Parse(source1) });
             comp.VerifyDiagnostics(
-                // (6,33): warning CS0612: 'A' is obsolete
+                // (9,17): error CS1667: Attribute 'Windows.Foundation.Metadata.DeprecatedAttribute' is not valid on property or event accessors. It is only valid on 'assembly, module, class, struct, enum, constructor, method, property, indexer, field, event, interface, parameter, delegate, return, type parameter' declarations.
+                //     object R { [Deprecated(null, DeprecationType.Deprecate, 0)] get { return new C(); } }
+                Diagnostic(ErrorCode.ERR_AttributeNotOnAccessor, "Deprecated").WithArguments("Windows.Foundation.Metadata.DeprecatedAttribute", "assembly, module, class, struct, enum, constructor, method, property, indexer, field, event, interface, parameter, delegate, return, type parameter").WithLocation(9, 17),
+                // (7,33): warning CS0612: 'A' is obsolete
                 //     object P { get { return new A(); } }
-                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "A").WithArguments("A").WithLocation(6, 33));
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "A").WithArguments("A").WithLocation(7, 33),
+                // (9,82): warning CS0612: 'C' is obsolete
+                //     object R { [Deprecated(null, DeprecationType.Deprecate, 0)] get { return new C(); } }
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "C").WithArguments("C").WithLocation(9, 82));
         }
 
         [Fact]
         public void TestObsoleteAndEventAccessors()
         {
-            var source =
+            var source0 =
 @"using System;
-[Obsolete] class A { }
-[Obsolete] class B { }
-class C
+namespace Windows.Foundation.Metadata
+{
+    public sealed class DeprecatedAttribute : Attribute
+    {
+        public DeprecatedAttribute(System.String message, DeprecationType type, System.UInt32 version)
+        {
+        }
+    }
+    public enum DeprecationType
+    {
+        Deprecate = 0,
+        Remove = 1
+    }
+}";
+            var source1 =
+@"using System;
+using Windows.Foundation.Metadata;
+[Deprecated(null, DeprecationType.Deprecate, 0)] class A { }
+[Deprecated(null, DeprecationType.Deprecate, 0)] class B { }
+[Deprecated(null, DeprecationType.Deprecate, 0)] class C { }
+class D
 {
-    event EventHandler E { add { } remove { M(new A()); } }
-    [Obsolete] event EventHandler F { add { } remove { M(new B()); } }
+    event EventHandler E
+    {
+        add { }
+        remove { M(new A()); }
+    }
+    [Deprecated(null, DeprecationType.Deprecate, 0)] event EventHandler F
+    {
+        add { }
+        remove { M(new B()); }
+    }
+    event EventHandler G
+    {
+        add { }
+        [Deprecated(null, DeprecationType.Deprecate, 0)] remove { M(new C()); }
+    }
     static void M(object o) { }
 }";
-            var comp = CreateCompilationWithMscorlibAndSystemCore(source);
+            var comp = CreateStandardCompilation(new[] { Parse(source0), Parse(source1) });
             comp.VerifyDiagnostics(
-                // (6,51): warning CS0612: 'A' is obsolete
-                //     event EventHandler E { add { } remove { M(new A()); } }
-                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "A").WithArguments("A").WithLocation(6, 51));
+                // (21,10): error CS1667: Attribute 'Windows.Foundation.Metadata.DeprecatedAttribute' is not valid on property or event accessors. It is only valid on 'assembly, module, class, struct, enum, constructor, method, property, indexer, field, event, interface, parameter, delegate, return, type parameter' declarations.
+                //         [Deprecated(null, DeprecationType.Deprecate, 0)] remove { M(new C()); }
+                Diagnostic(ErrorCode.ERR_AttributeNotOnAccessor, "Deprecated").WithArguments("Windows.Foundation.Metadata.DeprecatedAttribute", "assembly, module, class, struct, enum, constructor, method, property, indexer, field, event, interface, parameter, delegate, return, type parameter"),
+                // (11,24): warning CS0612: 'A' is obsolete
+                //         remove { M(new A()); }
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "A").WithArguments("A"),
+                // (21,73): warning CS0612: 'C' is obsolete
+                //         [Deprecated(null, DeprecationType.Deprecate, 0)] remove { M(new C()); }
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbol, "C").WithArguments("C").WithLocation(21, 73));
         }
 
         [Fact]

src/Compilers/VisualBasic/Portable/Symbols/ObsoleteAttributeHelpers.vb

@@ -46,11 +46,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
         ''' </returns>
         Private Shared Function GetObsoleteContextState(symbol As Symbol, forceComplete As Boolean) As ThreeState
             While symbol IsNot Nothing
-                ' For property or event accessors, check the associated property or event instead.
-                If symbol.IsAccessor() Then
-                    symbol = DirectCast(symbol, MethodSymbol).AssociatedSymbol
-                End If
-
                 If forceComplete Then
                     symbol.ForceCompleteObsoleteAttribute()
                 End If
@@ -60,7 +55,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                     Return state
                 End If
 
-                symbol = symbol.ContainingSymbol
+                ' For property or event accessors, check the associated property or event instead.
+                If symbol.IsAccessor() Then
+                    symbol = DirectCast(symbol, MethodSymbol).AssociatedSymbol
+                Else
+                    symbol = symbol.ContainingSymbol
+                End If
             End While
 
             Return ThreeState.False

src/Compilers/VisualBasic/Test/Emit/Attributes/AttributeTests_ObsoleteAttribute.vb

@@ -719,24 +719,43 @@ End Class
 <compilation>
     <file><![CDATA[
 Imports System
-<Obsolete>
-Class A
+Namespace Windows.Foundation.Metadata
+    Public NotInheritable Class DeprecatedAttribute
+        Inherits Attribute
+        Public Sub New(message As String, type As DeprecationType, version As UInteger)
+        End Sub
+    End Class
+    Public Enum DeprecationType
+        Deprecate
+        Remove
+    End Enum
+End Namespace
+]]>
+    </file>
+    <file><![CDATA[
+Imports Windows.Foundation.Metadata
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class A
 End Class
-<Obsolete>
-Class B
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class B
 End Class
-Class C
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class C
+End Class
+Class D
     ReadOnly Property P As Object
         Get
             Return New A()
         End Get
     End Property
-    <Obsolete>
-    ReadOnly Property Q As Object
+    <Deprecated(Nothing, DeprecationType.Deprecate, 0)>ReadOnly Property Q As Object
         Get
             Return New B()
         End Get
     End Property
+    ReadOnly Property R As Object
+        <Deprecated(Nothing, DeprecationType.Deprecate, 0)>Get
+            Return New C()
+        End Get
+    End Property
 End Class
 ]]>
     </file>
@@ -751,13 +770,29 @@ End Class
 <compilation>
     <file><![CDATA[
 Imports System
-<Obsolete>
-Class A
+Namespace Windows.Foundation.Metadata
+    Public NotInheritable Class DeprecatedAttribute
+        Inherits Attribute
+        Public Sub New(message As String, type As DeprecationType, version As UInteger)
+        End Sub
+    End Class
+    Public Enum DeprecationType
+        Deprecate
+        Remove
+    End Enum
+End Namespace
+]]>
+    </file>
+    <file><![CDATA[
+Imports System
+Imports Windows.Foundation.Metadata
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class A
 End Class
-<Obsolete>
-Class B
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class B
 End Class
-Class C
+<Deprecated(Nothing, DeprecationType.Deprecate, 0)>Class C
+End Class
+Class D
     Custom Event E As EventHandler
         AddHandler(value As EventHandler)
         End AddHandler
@@ -767,8 +802,7 @@ Class C
         RaiseEvent
         End RaiseEvent
     End Event
-    <Obsolete>
-    Custom Event F As EventHandler
+    <Deprecated(Nothing, DeprecationType.Deprecate, 0)>Custom Event F As EventHandler
         AddHandler(value As EventHandler)
         End AddHandler
         RemoveHandler(value As EventHandler)
@@ -777,6 +811,15 @@ Class C
         RaiseEvent
         End RaiseEvent
     End Event
+    Custom Event G As EventHandler
+        AddHandler(value As EventHandler)
+        End AddHandler
+        <Deprecated(Nothing, DeprecationType.Deprecate, 0)>RemoveHandler(value As EventHandler)
+            M(New C())
+        End RemoveHandler
+        RaiseEvent
+        End RaiseEvent
+    End Event
     Shared Sub M(o As Object)
     End Sub
 End Class
@@ -784,7 +827,8 @@ End Class
     </file>
 </compilation>
             CreateCompilationWithMscorlib(source).VerifyDiagnostics(
-                Diagnostic(ERRID.WRN_UseOfObsoleteSymbolNoMessage1, "A").WithArguments("A").WithLocation(13, 19))
+                Diagnostic(ERRID.ERR_ObsoleteInvalidOnEventMember, "<Deprecated(Nothing, DeprecationType.Deprecate, 0)>RemoveHandler(value As EventHandler)").WithArguments("Windows.Foundation.Metadata.DeprecatedAttribute").WithLocation(31, 9),
+                Diagnostic(ERRID.WRN_UseOfObsoleteSymbolNoMessage1, "A").WithArguments("A").WithLocation(14, 19))
         End Sub
 
         <Fact>