Do not suppress warnings within [Experimental] member

src/Compilers/CSharp/Portable/Binder/Binder.cs

@@ -559,52 +559,41 @@ internal static ThreeState ReportDiagnosticsIfObsoleteInternal(DiagnosticBag dia
         {
             Debug.Assert(diagnostics != null);
 
-            if (symbol.ObsoleteState == ThreeState.False)
-            {
-                return ThreeState.False;
-            }
-
-            var data = symbol.ObsoleteAttributeData;
-            if (data == null)
-            {
-                // Obsolete attribute has errors.
-                return ThreeState.False;
-            }
-
-            // If we haven't cracked attributes on the symbol at all or we haven't
-            // cracked attribute arguments enough to be able to report diagnostics for
-            // ObsoleteAttribute, store the symbol so that we can report diagnostics at a 
-            // later stage.
-            if (symbol.ObsoleteState == ThreeState.Unknown)
-            {
-                diagnostics.Add(new LazyObsoleteDiagnosticInfo(symbol, containingMember, location), node.GetLocation());
-                return ThreeState.Unknown;
-            }
-
-            // After this point, always return True.
-
-            var inObsoleteContext = ObsoleteAttributeHelpers.GetObsoleteContextState(containingMember);
-
-            // If we are in a context that is already obsolete, there is no point reporting
-            // more obsolete diagnostics.
-            if (inObsoleteContext == ThreeState.True)
-            {
-                return ThreeState.True;
-            }
-            // If the context is unknown, then store the symbol so that we can do this check at a
-            // later stage
-            else if (inObsoleteContext == ThreeState.Unknown)
-            {
-                diagnostics.Add(new LazyObsoleteDiagnosticInfo(symbol, containingMember, location), node.GetLocation());
-                return ThreeState.True;
-            }
-
-            // We have all the information we need to report diagnostics right now. So do it.
-            var diagInfo = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(symbol, location);
-            if (diagInfo != null)
-            {
-                diagnostics.Add(diagInfo, node.GetLocation());
-                return ThreeState.True;
+            var kind = symbol.ObsoleteKind;
+            switch (kind)
+            {
+                case ObsoleteAttributeKind.None:
+                    return ThreeState.False;
+                case ObsoleteAttributeKind.Uninitialized:
+                    // If we haven't cracked attributes on the symbol at all or we haven't
+                    // cracked attribute arguments enough to be able to report diagnostics for
+                    // ObsoleteAttribute, store the symbol so that we can report diagnostics at a 
+                    // later stage.
+                    diagnostics.Add(new LazyObsoleteDiagnosticInfo(symbol, containingMember, location), node.GetLocation());
+                    return ThreeState.Unknown;
+            }
+
+            kind = containingMember.GetObsoleteContextKind();
+            switch (kind)
+            {
+                case ObsoleteAttributeKind.None:
+                case ObsoleteAttributeKind.Experimental:
+                    // We have all the information we need to report diagnostics right now. So do it.
+                    var diagInfo = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(symbol, location);
+                    if (diagInfo != null)
+                    {
+                        diagnostics.Add(diagInfo, node.GetLocation());
+                    }
+                    break;
+                case ObsoleteAttributeKind.Uninitialized:
+                    // If the context is unknown, then store the symbol so that we can do this check at a
+                    // later stage
+                    diagnostics.Add(new LazyObsoleteDiagnosticInfo(symbol, containingMember, location), node.GetLocation());
+                    break;
+                default:
+                    // If we are in a context that is already obsolete, there is no point reporting
+                    // more obsolete diagnostics.
+                    break;
             }
 
             return ThreeState.True;

src/Compilers/CSharp/Portable/Errors/LazyObsoleteDiagnosticInfo.cs

@@ -33,10 +33,10 @@ internal override DiagnosticInfo GetResolvedInfo()
 
                 if (_symbol.ObsoleteState == ThreeState.True)
                 {
-                    var inObsoleteContext = ObsoleteAttributeHelpers.GetObsoleteContextState(_containingSymbol, forceComplete: true);
-                    Debug.Assert(inObsoleteContext != ThreeState.Unknown);
+                    var kind = _containingSymbol.GetObsoleteContextKind(forceComplete: true);
+                    Debug.Assert(kind != ObsoleteAttributeKind.Uninitialized);
 
-                    if (inObsoleteContext == ThreeState.False)
+                    if (kind == ObsoleteAttributeKind.None)
                     {
                         DiagnosticInfo info = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(_symbol, _binderFlags);
                         if (info != null)

src/Compilers/CSharp/Portable/Symbols/ObsoleteAttributeHelpers.cs

@@ -39,37 +39,42 @@ internal static ObsoleteAttributeData GetObsoleteDataFromMetadata(EntityHandle t
         /// This method checks to see if the given symbol is Obsolete or if any symbol in the parent hierarchy is Obsolete.
         /// </summary>
         /// <returns>
-        /// True if some symbol in the parent hierarchy is known to be Obsolete. Unknown if any
-        /// symbol's Obsoleteness is Unknown. False, if we are certain that no symbol in the parent
-        /// hierarchy is Obsolete.
+        /// Uninitialized if attributes have not been cracked yet.
         /// </returns>
-        internal static ThreeState GetObsoleteContextState(Symbol symbol, bool forceComplete = false)
+        internal static ObsoleteAttributeKind GetObsoleteContextKind(this Symbol symbol, bool forceComplete = false)
         {
-            if ((object)symbol == null)
-                return ThreeState.False;
-
-            // For Property or Event accessors, check the associated property or event instead.
-            if (symbol.IsAccessor())
-            {
-                symbol = ((MethodSymbol)symbol).AssociatedSymbol;
-            }
-            // If this is the backing field of an event, look at the event instead.
-            else if (symbol.Kind == SymbolKind.Field && (object)((FieldSymbol)symbol).AssociatedSymbol != null)
+            while ((object)symbol != null)
             {
-                symbol = ((FieldSymbol)symbol).AssociatedSymbol;
-            }
+                // For property or event accessors, check the associated property or event instead.
+                if (symbol.IsAccessor())
+                {
+                    symbol = ((MethodSymbol)symbol).AssociatedSymbol;
+                }
+                else if (symbol.Kind == SymbolKind.Field)
+                {
+                    // If this is the backing field of an event, look at the event instead.
+                    var associatedSymbol = ((FieldSymbol)symbol).AssociatedSymbol;
+                    if ((object)associatedSymbol != null)
+                    {
+                        symbol = associatedSymbol;
+                    }
+                }
 
-            if (forceComplete)
-            {
-                symbol.ForceCompleteObsoleteAttribute();
-            }
+                if (forceComplete)
+                {
+                    symbol.ForceCompleteObsoleteAttribute();
+                }
 
-            if (symbol.ObsoleteState != ThreeState.False)
-            {
-                return symbol.ObsoleteState;
+                var kind = symbol.ObsoleteKind;
+                if (kind != ObsoleteAttributeKind.None)
+                {
+                    return kind;
+                }
+
+                symbol = symbol.ContainingSymbol;
             }
 
-            return GetObsoleteContextState(symbol.ContainingSymbol, forceComplete);
+            return ObsoleteAttributeKind.None;
         }
 
         /// <summary>
@@ -79,10 +84,10 @@ internal static ThreeState GetObsoleteContextState(Symbol symbol, bool forceComp
         internal static DiagnosticInfo CreateObsoleteDiagnostic(Symbol symbol, BinderFlags location)
         {
             var data = symbol.ObsoleteAttributeData;
+            Debug.Assert(data != null);
 
             if (data == null)
             {
-                // ObsoleteAttribute had errors.
                 return null;
             }
 

src/Compilers/CSharp/Portable/Symbols/Symbol.cs

@@ -1018,22 +1018,28 @@ internal ThreeState ObsoleteState
         {
             get
             {
-                var data = this.ObsoleteAttributeData;
-                if (data == null)
-                {
-                    return ThreeState.False;
-                }
-                else if (data.IsUninitialized)
+                switch (ObsoleteKind)
                 {
-                    return ThreeState.Unknown;
-                }
-                else
-                {
-                    return ThreeState.True;
+                    case ObsoleteAttributeKind.None:
+                        return ThreeState.False;
+                    case ObsoleteAttributeKind.Uninitialized:
+                        return ThreeState.Unknown;
+                    default:
+                        return ThreeState.True;
                 }
             }
         }
 
+        internal ObsoleteAttributeKind ObsoleteKind
+        {
+            get
+            {
+                var data = this.ObsoleteAttributeData;
+                return (data == null) ? ObsoleteAttributeKind.None : data.Kind;
+            }
+        }
+
+
         /// <summary>
         /// Returns data decoded from <see cref="ObsoleteAttribute"/> attribute or null if there is no <see cref="ObsoleteAttribute"/> attribute.
         /// This property returns <see cref="Microsoft.CodeAnalysis.ObsoleteAttributeData.Uninitialized"/> if attribute arguments haven't been decoded yet.

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

@@ -167,8 +167,6 @@ static void Main()
                 Diagnostic(ErrorCode.WRN_Experimental, "((I)o).F()").WithArguments("I.F()").WithLocation(11, 9));
         }
 
-        // [Obsolete] and [Deprecated] diagnostics are not
-        // suppressed inside [Experimental] type.
         [Fact]
         public void TestExperimentalTypeWithDeprecatedAndObsoleteMembers()
         {
@@ -227,8 +225,62 @@ static void F(A a)
                 Diagnostic(ErrorCode.WRN_Experimental, "A.B").WithArguments("A.B").WithLocation(27, 14));
         }
 
+        // Diagnostics for [Obsolete] members
+        // are not suppressed in [Experimental] types.
+        [Fact]
+        public void TestObsoleteMembersInExperimentalType()
+        {
+            var source =
+@"using System;
+using Windows.Foundation.Metadata;
+class A
+{
+    internal void F0() { }
+    [Deprecated("""", DeprecationType.Deprecate, 0)]
+    internal void F1() { }
+    [Deprecated("""", DeprecationType.Remove, 0)]
+    internal void F2() { }
+    [Obsolete("""", false)]
+    internal void F3() { }
+    [Obsolete("""", true)]
+    internal void F4() { }
+    [Experimental]
+    internal class B { }
+}
+[Experimental]
+class C
+{
+    static void F(A a)
+    {
+        a.F0();
+        a.F1();
+        a.F2();
+        a.F3();
+        a.F4();
+        (new A.B()).ToString();
+    }
+}";
+            var comp = CreateCompilationWithMscorlibAndSystemCore(new[] { Parse(DeprecatedAttributeSource), Parse(ExperimentalAttributeSource), Parse(source) });
+            comp.VerifyDiagnostics(
+                // (23,9): warning CS0618: 'A.F1()' is obsolete: ''
+                //         a.F1();
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbolStr, "a.F1()").WithArguments("A.F1()", "").WithLocation(23, 9),
+                // (24,9): error CS0619: 'A.F2()' is obsolete: ''
+                //         a.F2();
+                Diagnostic(ErrorCode.ERR_DeprecatedSymbolStr, "a.F2()").WithArguments("A.F2()", "").WithLocation(24, 9),
+                // (25,9): warning CS0618: 'A.F3()' is obsolete: ''
+                //         a.F3();
+                Diagnostic(ErrorCode.WRN_DeprecatedSymbolStr, "a.F3()").WithArguments("A.F3()", "").WithLocation(25, 9),
+                // (26,9): error CS0619: 'A.F4()' is obsolete: ''
+                //         a.F4();
+                Diagnostic(ErrorCode.ERR_DeprecatedSymbolStr, "a.F4()").WithArguments("A.F4()", "").WithLocation(26, 9),
+                // (27,14): warning CS8305: 'A.B' is for evaluation purposes only and is subject to change or removal in future updates.
+                //         (new A.B()).ToString();
+                Diagnostic(ErrorCode.WRN_Experimental, "A.B").WithArguments("A.B").WithLocation(27, 14));
+        }
+
         // Diagnostics for [Experimental] types
-        // are suppressed in [Obsolete] members.
+        // are not suppressed in [Obsolete] members.
         [Fact]
         public void TestExperimentalTypeInObsoleteMember()
         {

src/Compilers/Core/Portable/Symbols/Attributes/ObsoleteAttributeData.cs

@@ -7,6 +7,7 @@ namespace Microsoft.CodeAnalysis
     internal enum ObsoleteAttributeKind
     {
         None,
+        Uninitialized,
         Obsolete,
         Deprecated,
         Experimental,
@@ -17,7 +18,7 @@ internal enum ObsoleteAttributeKind
     /// </summary>
     internal sealed class ObsoleteAttributeData
     {
-        public static readonly ObsoleteAttributeData Uninitialized = new ObsoleteAttributeData(ObsoleteAttributeKind.None, null, false);
+        public static readonly ObsoleteAttributeData Uninitialized = new ObsoleteAttributeData(ObsoleteAttributeKind.Uninitialized, null, false);
         public static readonly ObsoleteAttributeData Experimental = new ObsoleteAttributeData(ObsoleteAttributeKind.Experimental, null, false);
 
         public ObsoleteAttributeData(ObsoleteAttributeKind kind, string message, bool isError)

src/Compilers/VisualBasic/Portable/Binding/Binder.vb

@@ -895,43 +895,35 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Debug.Assert(context IsNot Nothing)
             Debug.Assert(symbol IsNot Nothing)
 
-            If symbol.ObsoleteState = ThreeState.False Then
-                Return
-            End If
-
-            Dim data = symbol.ObsoleteAttributeData
-            If data Is Nothing Then
-                ' Obsolete attribute has errors.
-                Return
-            End If
-
-            ' If we haven't cracked attributes on the symbol at all or we haven't
-            ' cracked attribute arguments enough to be able to report diagnostics for
-            ' ObsoleteAttribute, store the symbol so that we can report diagnostics at a 
-            ' later stage.
-            If symbol.ObsoleteState = ThreeState.Unknown OrElse data.IsUninitialized Then
-                diagnostics.Add(New LazyObsoleteDiagnosticInfo(symbol, context), node.GetLocation())
-                Return
-            End If
-
-            Dim inObsoleteContext = ObsoleteAttributeHelpers.GetObsoleteContextState(context)
-
-            ' If we are in a context that is already obsolete, there is no point reporting
-            ' more obsolete diagnostics.
-            If inObsoleteContext = ThreeState.True Then
-                Return
-            ElseIf inObsoleteContext = ThreeState.Unknown Then
-                ' If the context is unknown, then store the symbol so that we can do this check at a
-                ' later stage
-                diagnostics.Add(New LazyObsoleteDiagnosticInfo(symbol, context), node.GetLocation())
-                Return
-            End If
-
-            ' We have all the information we need to report diagnostics right now. So do it.
-            Dim info = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(symbol)
-            If info IsNot Nothing Then
-                diagnostics.Add(info, node.GetLocation())
-            End If
+            Dim kind = symbol.ObsoleteKind
+            Select Case kind
+                Case ObsoleteAttributeKind.None
+                    Return
+                Case ObsoleteAttributeKind.Uninitialized
+                    ' If we haven't cracked attributes on the symbol at all or we haven't
+                    ' cracked attribute arguments enough to be able to report diagnostics for
+                    ' ObsoleteAttribute, store the symbol so that we can report diagnostics at a 
+                    ' later stage.
+                    diagnostics.Add(New LazyObsoleteDiagnosticInfo(symbol, context), node.GetLocation())
+                    Return
+            End Select
+
+            kind = ObsoleteAttributeHelpers.GetObsoleteContextKind(context)
+            Select Case kind
+                Case ObsoleteAttributeKind.None, ObsoleteAttributeKind.Experimental
+                    ' We have all the information we need to report diagnostics right now. So do it.
+                    Dim info = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(symbol)
+                    If info IsNot Nothing Then
+                        diagnostics.Add(info, node.GetLocation())
+                    End If
+                Case ObsoleteAttributeKind.Uninitialized
+                    ' If the context is unknown, then store the symbol so that we can do this check at a
+                    ' later stage
+                    diagnostics.Add(New LazyObsoleteDiagnosticInfo(symbol, context), node.GetLocation())
+                Case Else
+                    ' If we are in a context that is already obsolete, there is no point reporting
+                    ' more obsolete diagnostics.
+            End Select
         End Sub
 
         Friend Overridable ReadOnly Property SuppressObsoleteDiagnostics As Boolean

src/Compilers/VisualBasic/Portable/Errors/LazyObsoleteDiagnosticInfo.vb

@@ -26,10 +26,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 _symbol.ForceCompleteObsoleteAttribute()
 
                 If _symbol.ObsoleteState = ThreeState.True Then
-                    Dim inObsoleteContext = ObsoleteAttributeHelpers.GetObsoleteContextState(_containingSymbol, forceComplete:=True)
-                    Debug.Assert(inObsoleteContext <> ThreeState.Unknown)
+                    Dim kind = ObsoleteAttributeHelpers.GetObsoleteContextKind(_containingSymbol, forceComplete:=True)
+                    Debug.Assert(kind <> ObsoleteAttributeKind.Uninitialized)
 
-                    If inObsoleteContext = ThreeState.False Then
+                    If kind = ObsoleteAttributeKind.None Then
                         Dim info As DiagnosticInfo = ObsoleteAttributeHelpers.CreateObsoleteDiagnostic(_symbol)
                         If info IsNot Nothing Then
                             Interlocked.CompareExchange(Me._lazyActualObsoleteDiagnostic, info, Nothing)

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

 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 Imports System.Diagnostics
-Imports System.Threading
 Imports System.Reflection.Metadata
+Imports System.Threading
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
@@ -32,50 +32,39 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
         ''' This method checks to see if the given symbol is Obsolete or if any symbol in the parent hierarchy is Obsolete.
         ''' </summary>
         ''' <returns>
-        ''' True if some symbol in the parent hierarchy is known to be Obsolete. Unknown if any
-        ''' symbol's Obsoleteness is Unknown. False, if we are certain that no symbol in the parent
-        ''' hierarchy is Obsolete.
+        ''' Uninitialized if attributes have not been cracked yet.
         ''' </returns>
-        Friend Shared Function GetObsoleteContextState(symbol As Symbol, Optional forceComplete As Boolean = False) As ThreeState
-            If symbol Is Nothing Then
-                Return ThreeState.False
-            End If
-
-            If forceComplete Then
-                symbol.ForceCompleteObsoleteAttribute()
-            End If
+        Friend Shared Function GetObsoleteContextKind(symbol As Symbol, Optional forceComplete As Boolean = False) As ObsoleteAttributeKind
+            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
 
-            Dim associatedPropertyOrEvent = If(symbol.IsAccessor(), DirectCast(symbol, MethodSymbol).AssociatedSymbol, Nothing)
+                If forceComplete Then
+                    symbol.ForceCompleteObsoleteAttribute()
+                End If
 
-            ' If this is an event accessor, then consider the event itself for context since
-            ' event accessors cannot be marked obsolete.
-            If associatedPropertyOrEvent IsNot Nothing AndAlso associatedPropertyOrEvent.Kind = SymbolKind.Event Then
-                symbol = DirectCast(symbol, MethodSymbol).AssociatedSymbol
-            End If
+                Dim kind = symbol.ObsoleteKind
+                If kind <> ObsoleteAttributeKind.None Then
+                    Return kind
+                End If
 
-            If symbol.ObsoleteState <> ThreeState.False Then
-                Return symbol.ObsoleteState
-            End If
+                symbol = symbol.ContainingSymbol
+            End While
 
-            ' If this is a property accessor then check the property for obsoleteness as well so that we suppress
-            ' obsolete diagnostics anywhere inside a property.
-            If associatedPropertyOrEvent IsNot Nothing AndAlso associatedPropertyOrEvent.Kind = SymbolKind.Property Then
-                Return GetObsoleteContextState(associatedPropertyOrEvent, forceComplete)
-            Else
-                Return GetObsoleteContextState(symbol.ContainingSymbol, forceComplete)
-            End If
+            Return ObsoleteAttributeKind.None
         End Function
 
-
         ''' <summary>
         ''' Create a diagnostic for the given symbol. This could be an error or a warning based on
         ''' the ObsoleteAttribute's arguments.
         ''' </summary>
         Friend Shared Function CreateObsoleteDiagnostic(symbol As Symbol) As DiagnosticInfo
             Dim data = symbol.ObsoleteAttributeData
+            Debug.Assert(data IsNot Nothing)
 
             If data Is Nothing Then
-                ' ObsoleteAttribute had errors.
                 Return Nothing
             End If
 

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

@@ -423,15 +423,22 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         ''' This property returns Unknown if the Obsolete Attribute hasn't been cracked yet.
         ''' </summary>
         Friend ReadOnly Property ObsoleteState As ThreeState
+            Get
+                Select Case ObsoleteKind
+                    Case ObsoleteAttributeKind.None
+                        Return ThreeState.False
+                    Case ObsoleteAttributeKind.Uninitialized
+                        Return ThreeState.Unknown
+                    Case Else
+                        Return ThreeState.True
+                End Select
+            End Get
+        End Property
+
+        Friend ReadOnly Property ObsoleteKind As ObsoleteAttributeKind
             Get
                 Dim data = Me.ObsoleteAttributeData
-                If data Is Nothing Then
-                    Return ThreeState.False
-                ElseIf data Is ObsoleteAttributeData.Uninitialized Then
-                    Return ThreeState.Unknown
-                Else
-                    Return ThreeState.True
-                End If
+                Return If(data Is Nothing, ObsoleteAttributeKind.None, data.Kind)
             End Get
         End Property
 

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

@@ -210,8 +210,6 @@ End Class
 </compilation>
         End Sub
 
-        ' <Obsolete> and <Deprecated> diagnostics are not
-        ' suppressed inside <Experimental> type.
         <Fact()>
         Public Sub TestExperimentalTypeWithDeprecatedAndObsoleteMembers()
             Dim comp0 = CreateCompilationWithMscorlib(DeprecatedAndExperimentalAttributeSource)
@@ -282,8 +280,74 @@ BC42380: 'A.B' is for evaluation purposes only and is subject to change or remov
      </errors>)
         End Sub
 
+        ' Diagnostics for <Obsolete> members
+        ' are not suppressed in <Experimental> types.
+        <Fact()>
+        Public Sub TestObsoleteMembersInExperimentalType()
+            Dim comp0 = CreateCompilationWithMscorlib(DeprecatedAndExperimentalAttributeSource)
+            comp0.AssertNoDiagnostics()
+            Dim ref0 = comp0.EmitToImageReference()
+
+            Dim source =
+<compilation>
+    <file><![CDATA[
+Imports System
+Imports Windows.Foundation.Metadata
+Class A
+    Friend Sub F0()
+    End Sub
+    <Deprecated("", DeprecationType.Deprecate, 0)>
+    Friend Sub F1()
+    End Sub
+    <Deprecated("", DeprecationType.Remove, 0)>
+    Friend Sub F2()
+    End Sub
+    <Obsolete("", False)>
+    Friend Sub F3()
+    End Sub
+    <Obsolete("", True)>
+    Friend Sub F4()
+    End Sub
+    <Experimental>
+    Friend Class B
+    End Class
+End Class
+<Experimental>
+Class C
+    Shared Sub F(a As A)
+        a.F0()
+        a.F1()
+        a.F2()
+        a.F3()
+        a.F4()
+        Dim b = New A.B()
+    End Sub
+End Class
+]]>
+    </file>
+</compilation>
+            Dim comp = CreateCompilationWithMscorlib(source, references:={ref0})
+            comp.AssertTheseDiagnostics(<errors>
+BC40008: 'Friend Sub F1()' is obsolete.
+        a.F1()
+        ~~~~~~
+BC31075: 'Friend Sub F2()' is obsolete.
+        a.F2()
+        ~~~~~~
+BC40008: 'Friend Sub F3()' is obsolete.
+        a.F3()
+        ~~~~~~
+BC31075: 'Friend Sub F4()' is obsolete.
+        a.F4()
+        ~~~~~~
+BC42380: 'A.B' is for evaluation purposes only and is subject to change or removal in future updates.
+        Dim b = New A.B()
+                    ~~~
+     </errors>)
+        End Sub
+
         ' Diagnostics for <Experimental> types
-        ' are suppressed in [Obsolete] members.
+        ' are not suppressed in <Obsolete> members.
         <Fact()>
         Public Sub TestExperimentalTypeInObsoleteMember()
             Dim comp0 = CreateCompilationWithMscorlib(DeprecatedAndExperimentalAttributeSource)