Bug 217681: compiler should not crash on public+private metadata

src/Compilers/CSharp/Portable/Symbols/Metadata/PE/PEFieldSymbol.cs

@@ -413,7 +413,8 @@ public override Accessibility DeclaredAccessibility
                         break;
 
                     default:
-                        throw ExceptionUtilities.UnexpectedValue(_flags & FieldAttributes.FieldAccessMask);
+                        access = Accessibility.Private;
+                        break;
                 }
 
                 return access;

src/Compilers/CSharp/Portable/Symbols/Metadata/PE/PEMethodSymbol.cs

@@ -354,7 +354,7 @@ public override Accessibility DeclaredAccessibility
                         return Accessibility.Protected;
 
                     default:
-                        throw ExceptionUtilities.UnexpectedValue(_flags);
+                        return Accessibility.Private;
                 }
             }
         }

src/Compilers/CSharp/Test/Symbol/Symbols/Metadata/PE/LoadingMethods.cs

@@ -1346,5 +1346,38 @@ instance void  .ctor() cil managed
             var method = type.GetMember<MethodSymbol>("M");
             Assert.NotNull(method.ReturnType);
         }
+
+        [Fact, WorkItem(217681, "https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems?id=217681")]
+        public void LoadingMethodWithPublicAndPrivateAccessibility()
+        {
+            string source =
+@"
+public class D
+{
+   public static void Main()
+   {
+      new C().M();
+      System.Console.WriteLine(new C().F);
+      new C.C2().M2();
+   }
+}
+";
+            var references = new[] { MetadataReference.CreateFromImage(TestResources.SymbolsTests.Metadata.PublicAndPrivateFlags) };
+
+            var comp = CreateCompilationWithMscorlib(source, references: references);
+
+            // The method, field and nested type with public and private accessibility flags get loaded as private.
+            comp.VerifyDiagnostics(
+                // (6,15): error CS0122: 'C.M()' is inaccessible due to its protection level
+                //       new C().M();
+                Diagnostic(ErrorCode.ERR_BadAccess, "M").WithArguments("C.M()").WithLocation(6, 15),
+                // (7,40): error CS0122: 'C.F' is inaccessible due to its protection level
+                //       System.Console.WriteLine(new C().F);
+                Diagnostic(ErrorCode.ERR_BadAccess, "F").WithArguments("C.F").WithLocation(7, 40),
+                // (8,13): error CS0122: 'C.C2' is inaccessible due to its protection level
+                //       new C.C2().M2();
+                Diagnostic(ErrorCode.ERR_BadAccess, "C2").WithArguments("C.C2").WithLocation(8, 13)
+                );
+        }
     }
 }

src/Compilers/Test/Resources/Core/CompilerTestResources.csproj

@@ -137,6 +137,7 @@
     <Content Include="NetFX\Minimal\Key.snk" />
     <Content Include="NetFX\Minimal\minasync.cs" />
     <Content Include="NetFX\Minimal\mincorlib.cs" />
+    <EmbeddedResource Include="SymbolsTests\Metadata\public-and-private.dll" />
     <Content Include="SymbolsTests\NoPia\ParametersWithoutNames.cs" />
     <EmbeddedResource Include="PerfTests\CSPerfTest.cs" />
     <Content Include="Resources\License.txt" />
@@ -418,6 +419,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ResourceLoader.cs" />
+    <None Include="SymbolsTests\Metadata\public-and-private.cs" />
     <Compile Include="TestKeys.cs" />
     <Compile Include="TestResources.cs" />
   </ItemGroup>

src/Compilers/Test/Resources/Core/SymbolsTests/Metadata/public-and-private.cs

@@ -0,0 +1,235 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+// This relates to VSO bug 217681 https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems?id=217681
+// The code below is compiled with a modified compiler such that MetadataWriter will set both public and private flags on M, F, C2 and M2.
+// But the constructors should be left public.
+// You can also see the resulting meta info at the bottom
+
+public class C
+{
+   public void M() { System.Console.WriteLine("I am C!"); }
+   public int F = 42;
+
+   public class C2
+   {
+      public void M2() { System.Console.WriteLine("I am C2!"); }
+   }
+}
+
+string metainfo = @"
+===========================================================
+ScopeName : public-and-private.dll
+MVID      : {3C7CF08B-32C8-4C36-BD58-85DEB7FA5843}
+===========================================================
+Global functions
+-------------------------------------------------------
+
+Global fields
+-------------------------------------------------------
+
+Global MemberRefs
+-------------------------------------------------------
+
+TypeDef #1 (02000002)
+-------------------------------------------------------
+	TypDefName: C  (02000002)
+	Flags     : [Public] [AutoLayout] [Class] [AnsiClass] [BeforeFieldInit]  (00100001)
+	Extends   : 01000005 [TypeRef] System.Object
+	Field #1 (04000001)
+	-------------------------------------------------------
+		Field Name: F (04000001)
+		Flags     : [none] (00000007)
+		CallCnvntn: [FIELD]
+		Field type:  I4
+
+	Method #1 (06000001)
+	-------------------------------------------------------
+		MethodName: M (06000001)
+		Flags     : [HideBySig] [ReuseSlot]  (00000087)
+		RVA       : 0x00002050
+		ImplFlags : [IL] [Managed]  (00000000)
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+	Method #2 (06000002)
+	-------------------------------------------------------
+		MethodName: .ctor (06000002)
+		Flags     : [Public] [HideBySig] [ReuseSlot] [SpecialName] [RTSpecialName] [.ctor]  (00001886)
+		RVA       : 0x0000205e
+		ImplFlags : [IL] [Managed]  (00000000)
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+
+TypeDef #2 (02000003)
+-------------------------------------------------------
+	TypDefName: C2  (02000003)
+	Flags     : [NestedFamORAssem] [AutoLayout] [Class] [AnsiClass] [BeforeFieldInit]  (00100007)
+	Extends   : 01000005 [TypeRef] System.Object
+	EnclosingClass : C (02000002)
+	Method #1 (06000003)
+	-------------------------------------------------------
+		MethodName: M2 (06000003)
+		Flags     : [HideBySig] [ReuseSlot]  (00000087)
+		RVA       : 0x0000206f
+		ImplFlags : [IL] [Managed]  (00000000)
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+	Method #2 (06000004)
+	-------------------------------------------------------
+		MethodName: .ctor (06000004)
+		Flags     : [Public] [HideBySig] [ReuseSlot] [SpecialName] [RTSpecialName] [.ctor]  (00001886)
+		RVA       : 0x0000207d
+		ImplFlags : [IL] [Managed]  (00000000)
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+
+TypeRef #1 (01000001)
+-------------------------------------------------------
+Token:             0x01000001
+ResolutionScope:   0x23000001
+TypeRefName:       System.Runtime.CompilerServices.CompilationRelaxationsAttribute
+	MemberRef #1 (0a000001)
+	-------------------------------------------------------
+		Member: (0a000001) .ctor:
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		1 Arguments
+			Argument #1:  I4
+
+TypeRef #2 (01000002)
+-------------------------------------------------------
+Token:             0x01000002
+ResolutionScope:   0x23000001
+TypeRefName:       System.Runtime.CompilerServices.RuntimeCompatibilityAttribute
+	MemberRef #1 (0a000002)
+	-------------------------------------------------------
+		Member: (0a000002) .ctor:
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+TypeRef #3 (01000003)
+-------------------------------------------------------
+Token:             0x01000003
+ResolutionScope:   0x23000001
+TypeRefName:       System.Diagnostics.DebuggableAttribute
+	MemberRef #1 (0a000003)
+	-------------------------------------------------------
+		Member: (0a000003) .ctor:
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		1 Arguments
+			Argument #1:  ValueClass DebuggingModes
+
+TypeRef #4 (01000004)
+-------------------------------------------------------
+Token:             0x01000004
+ResolutionScope:   0x01000003
+TypeRefName:       DebuggingModes
+
+TypeRef #5 (01000005)
+-------------------------------------------------------
+Token:             0x01000005
+ResolutionScope:   0x23000001
+TypeRefName:       System.Object
+	MemberRef #1 (0a000005)
+	-------------------------------------------------------
+		Member: (0a000005) .ctor:
+		CallCnvntn: [DEFAULT]
+		hasThis
+		ReturnType: Void
+		No arguments.
+
+TypeRef #6 (01000006)
+-------------------------------------------------------
+Token:             0x01000006
+ResolutionScope:   0x23000001
+TypeRefName:       System.Console
+	MemberRef #1 (0a000004)
+	-------------------------------------------------------
+		Member: (0a000004) WriteLine:
+		CallCnvntn: [DEFAULT]
+		ReturnType: Void
+		1 Arguments
+			Argument #1:  String
+
+Assembly
+-------------------------------------------------------
+	Token: 0x20000001
+	Name : public-and-private
+	Public Key    :
+	Hash Algorithm : 0x00008004
+	Version: 0.0.0.0
+	Major Version: 0x00000000
+	Minor Version: 0x00000000
+	Build Number: 0x00000000
+	Revision Number: 0x00000000
+	Locale: <null>
+	Flags : [none] (00000000)
+	CustomAttribute #1 (0c000001)
+	-------------------------------------------------------
+		CustomAttribute Type: 0a000001
+		CustomAttributeName: System.Runtime.CompilerServices.CompilationRelaxationsAttribute :: instance void .ctor(int32)
+		Length: 8
+		Value : 01 00 08 00 00 00 00 00                          >                <
+		ctor args: (8)
+
+	CustomAttribute #2 (0c000002)
+	-------------------------------------------------------
+		CustomAttribute Type: 0a000002
+		CustomAttributeName: System.Runtime.CompilerServices.RuntimeCompatibilityAttribute :: instance void .ctor()
+		Length: 30
+		Value : 01 00 01 00 54 02 16 57  72 61 70 4e 6f 6e 45 78 >    T  WrapNonEx<
+                      : 63 65 70 74 69 6f 6e 54  68 72 6f 77 73 01       >ceptionThrows   <
+		ctor args: ()
+
+	CustomAttribute #3 (0c000003)
+	-------------------------------------------------------
+		CustomAttribute Type: 0a000003
+		CustomAttributeName: System.Diagnostics.DebuggableAttribute :: instance void .ctor(value class DebuggingModes)
+		Length: 8
+		Value : 01 00 07 01 00 00 00 00                          >                <
+		ctor args: ( <can not decode> )
+
+
+AssemblyRef #1 (23000001)
+-------------------------------------------------------
+	Token: 0x23000001
+	Public Key or Token: b7 7a 5c 56 19 34 e0 89
+	Name: mscorlib
+	Version: 4.0.0.0
+	Major Version: 0x00000004
+	Minor Version: 0x00000000
+	Build Number: 0x00000000
+	Revision Number: 0x00000000
+	Locale: <null>
+	HashValue Blob:
+	Flags: [none] (00000000)
+
+
+User Strings
+-------------------------------------------------------
+70000001 : ( 7) L""I am C!""
+70000011 : ( 8) L""I am C2!""
+
+
+Coff symbol name overhead:  0
+===========================================================
+===========================================================
+===========================================================
+
+";

src/Compilers/Test/Resources/Core/TestResources.cs

@@ -405,6 +405,9 @@ public static class Metadata
 
         private static byte[] s_mscorlibNamespacesAndTypes;
         public static byte[] MscorlibNamespacesAndTypes => ResourceLoader.GetOrCreateResource(ref s_mscorlibNamespacesAndTypes, "SymbolsTests.Metadata.MscorlibNamespacesAndTypes.bsl");
+
+        private static byte[] s_publicAndPrivateFlags;
+        public static byte[] PublicAndPrivateFlags => ResourceLoader.GetOrCreateResource(ref s_publicAndPrivateFlags, "SymbolsTests.Metadata.public-and-private.dll");
     }
 
     public static class Methods

src/Compilers/VisualBasic/Portable/Symbols/Metadata/PE/PEFieldSymbol.vb

@@ -111,7 +111,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
                         access = Accessibility.Protected
 
                     Case Else
-                        Debug.Assert(False, "Unexpected!!!")
+                        access = Accessibility.Private
                 End Select
 
                 Return access

src/Compilers/VisualBasic/Portable/Symbols/Metadata/PE/PEMethodSymbol.vb

@@ -561,7 +561,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
                         access = Accessibility.Protected
 
                     Case Else
-                        Debug.Assert(False, "Unexpected!!!")
+                        access = Accessibility.Private
                 End Select
 
                 Return access

src/Compilers/VisualBasic/Test/Symbol/SymbolsTests/Metadata/PE/LoadingMethods.vb

@@ -6,8 +6,8 @@ Imports Microsoft.CodeAnalysis.Collections
 Imports Microsoft.CodeAnalysis.Test.Utilities
 Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic
-Imports Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
+Imports Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 Imports Roslyn.Test.Utilities
 
@@ -925,5 +925,35 @@ BC30657: 'VT' has a return type that is not supported or parameter types that ar
                             ~~
 ]]>)
         End Sub
+
+        <Fact, WorkItem(217681, "https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems?id=217681")>
+        Public Sub LoadingMethodWithPublicAndPrivateAccessibility()
+            Dim source =
+         <compilation>
+             <file>
+Class D
+   Shared Sub Main()
+      Dim test = new C()
+      test.M()
+      System.Console.WriteLine(test.F)
+
+      Dim test2 = new C.C2()
+      test2.M2()
+   End Sub
+End Class
+    </file>
+         </compilation>
+
+            Dim references = {MetadataReference.CreateFromImage(TestResources.SymbolsTests.Metadata.PublicAndPrivateFlags)}
+
+            Dim comp = CreateCompilationWithMscorlib(source, references:=references)
+            comp.VerifyDiagnostics(
+                Diagnostic(ERRID.ERR_InaccessibleMember3, "test.M").WithArguments("C", "Private Overloads Sub M()", "Private").WithLocation(4, 7),
+                Diagnostic(ERRID.ERR_InaccessibleSymbol2, "test.F").WithArguments("C.F", "Private").WithLocation(5, 32),
+                Diagnostic(ERRID.ERR_InaccessibleSymbol2, "C.C2").WithArguments("C.C2", "Protected Friend").WithLocation(7, 23),
+                Diagnostic(ERRID.ERR_InaccessibleMember3, "test2.M2").WithArguments("C2", "Private Overloads Sub M2()", "Private").WithLocation(8, 7)
+                )
+        End Sub
+
     End Class
 End Namespace

src/Workspaces/Core/Portable/FindSymbols/SymbolTree/SymbolTreeInfo_Metadata.cs

@@ -1,4 +1,6 @@
-using System;
+// Copyright (c) Microsoft.  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.Generic;
 using System.IO;
 using System.Linq;