Enable specifying top-level binder options via an internal compilatio…

…n option

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

@@ -21,6 +21,16 @@ internal partial class Binder
 
         internal readonly BinderFlags Flags;
 
+        /// <summary>
+        /// Used to create a root binder.
+        /// </summary>
+        internal Binder(CSharpCompilation compilation)
+        {
+            Debug.Assert(compilation != null);
+            this.Flags = compilation.Options.TopLevelBinderFlags;
+            this.Compilation = compilation;
+        }
+
         internal Binder(Binder next)
         {
             Debug.Assert(next != null);
@@ -29,13 +39,6 @@ internal Binder(Binder next)
             this.Compilation = next.Compilation;
         }
 
-        internal Binder(CSharpCompilation compilation)
-        {
-            Debug.Assert(compilation != null);
-            this.Flags = BinderFlags.None;
-            this.Compilation = compilation;
-        }
-
         protected Binder(Binder next, BinderFlags flags)
         {
             Debug.Assert(next != null);

src/Compilers/CSharp/Portable/CSharpCompilationOptions.cs

@@ -7,6 +7,7 @@
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Roslyn.Utilities;
 using System.Diagnostics;
+using System.ComponentModel;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {
@@ -27,6 +28,12 @@ public sealed class CSharpCompilationOptions : CompilationOptions, IEquatable<CS
         /// </summary>
         public ImmutableArray<string> Usings { get; private set; }
 
+        /// <summary>
+        /// Flags applied to the top-level binder created for each syntax tree in the compilation 
+        /// as well as for the binder of global imports.
+        /// </summary>
+        internal BinderFlags TopLevelBinderFlags { get; private set; }
+
         // Defaults correspond to the compiler's defaults or indicate that the user did not specify when that is significant.
         // That's significant when one option depends on another's setting. SubsystemVersion depends on Platform and Target.
         public CSharpCompilationOptions(
@@ -68,7 +75,8 @@ public CSharpCompilationOptions(
                    assemblyIdentityComparer: assemblyIdentityComparer,
                    strongNameProvider: strongNameProvider,
                    metadataImportOptions: MetadataImportOptions.Public,
-                   publicSign: publicSign)
+                   publicSign: publicSign,
+                   topLevelBinderFlags: BinderFlags.None)
         {
         }
 
@@ -101,7 +109,8 @@ internal CSharpCompilationOptions(
             AssemblyIdentityComparer assemblyIdentityComparer,
             StrongNameProvider strongNameProvider,
             MetadataImportOptions metadataImportOptions,
-            bool publicSign)
+            bool publicSign,
+            BinderFlags topLevelBinderFlags)
             : base(outputKind, reportSuppressedDiagnostics, moduleName, mainTypeName, scriptClassName,
                    cryptoKeyContainer, cryptoKeyFile, cryptoPublicKey, delaySign, publicSign, optimizationLevel, checkOverflow,
                    platform, generalDiagnosticOption, warningLevel, specificDiagnosticOptions.ToImmutableDictionaryOrEmpty(),
@@ -111,6 +120,7 @@ internal CSharpCompilationOptions(
         {
             this.Usings = usings.AsImmutableOrEmpty();
             this.AllowUnsafe = allowUnsafe;
+            this.TopLevelBinderFlags = topLevelBinderFlags;
         }
 
         private CSharpCompilationOptions(CSharpCompilationOptions other) : this(
@@ -141,10 +151,16 @@ private CSharpCompilationOptions(CSharpCompilationOptions other) : this(
             strongNameProvider: other.StrongNameProvider,
             metadataImportOptions: other.MetadataImportOptions,
             reportSuppressedDiagnostics: other.ReportSuppressedDiagnostics,
-            publicSign: other.PublicSign)
+            publicSign: other.PublicSign,
+            topLevelBinderFlags: other.TopLevelBinderFlags)
         {
         }
 
+        internal CSharpCompilationOptions WithTopLevelBinderFlags(BinderFlags flags)
+        {
+            return (flags == TopLevelBinderFlags) ? this : new CSharpCompilationOptions(this) { TopLevelBinderFlags = flags };
+        }
+
         internal override ImmutableArray<string> GetImports() => Usings;
 
         public new CSharpCompilationOptions WithOutputKind(OutputKind kind)
@@ -585,6 +601,7 @@ public bool Equals(CSharpCompilationOptions other)
             }
 
             return this.AllowUnsafe == other.AllowUnsafe &&
+                   this.TopLevelBinderFlags == other.TopLevelBinderFlags &&
                    (this.Usings == null ? other.Usings == null : this.Usings.SequenceEqual(other.Usings, StringComparer.Ordinal));
         }
 
@@ -597,7 +614,8 @@ public override int GetHashCode()
         {
             return Hash.Combine(base.GetHashCodeHelper(),
                    Hash.Combine(this.AllowUnsafe,
-                   Hash.Combine(Hash.CombineValues(this.Usings, StringComparer.Ordinal), 0)));
+                   Hash.Combine(Hash.CombineValues(this.Usings, StringComparer.Ordinal),
+                   Hash.Combine(TopLevelBinderFlags.GetHashCode(), 0))));
         }
 
         internal override Diagnostic FilterDiagnostic(Diagnostic diagnostic)
@@ -606,6 +624,7 @@ internal override Diagnostic FilterDiagnostic(Diagnostic diagnostic)
         }
 
         // 1.1 BACKCOMPAT OVERLOAD -- DO NOT TOUCH
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public CSharpCompilationOptions(
             OutputKind outputKind,
             string moduleName,
@@ -645,6 +664,7 @@ public CSharpCompilationOptions(
 
 
         // 1.0 BACKCOMPAT OVERLOAD -- DO NOT TOUCH
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public CSharpCompilationOptions(
             OutputKind outputKind,
             string moduleName,
@@ -685,6 +705,7 @@ public CSharpCompilationOptions(
         // Bad constructor -- DO NOT USE
         // Violates the rules for optional parameter overloads detailed at
         // https://github.com/dotnet/roslyn/blob/e8fdb391703dcb5712ff6a5b83d768d784cba4cf/docs/Adding%20Optional%20Parameters%20in%20Public%20API.md
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public CSharpCompilationOptions(
             OutputKind outputKind,
             bool reportSuppressedDiagnostics,
@@ -723,7 +744,8 @@ public CSharpCompilationOptions(
                    assemblyIdentityComparer: assemblyIdentityComparer,
                    strongNameProvider: strongNameProvider,
                    metadataImportOptions: MetadataImportOptions.Public,
-                   publicSign: false)
+                   publicSign: false,
+                   topLevelBinderFlags: BinderFlags.None)
         {
         }
     }

src/Compilers/CSharp/Test/Symbol/Compilation/CSharpCompilationOptionsTests.cs

@@ -86,6 +86,9 @@ public void Invariants()
             TestProperty((old, value) => old.WithMetadataReferenceResolver(value), opt => opt.MetadataReferenceResolver, new TestMetadataReferenceResolver());
             TestProperty((old, value) => old.WithAssemblyIdentityComparer(value), opt => opt.AssemblyIdentityComparer, new DesktopAssemblyIdentityComparer(new AssemblyPortabilityPolicy()));
             TestProperty((old, value) => old.WithStrongNameProvider(value), opt => opt.StrongNameProvider, new DesktopStrongNameProvider());
+
+            TestProperty((old, value) => old.WithTopLevelBinderFlags(value), opt => opt.TopLevelBinderFlags, BinderFlags.IgnoreCorLibraryDuplicatedTypes);
+            TestProperty((old, value) => old.WithMetadataImportOptions(value), opt => opt.MetadataImportOptions, MetadataImportOptions.Internal);
         }
 
         [Fact]
@@ -319,7 +322,8 @@ public void TestFieldsForEqualsAndGetHashCode()
             ReflectionAssert.AssertPublicAndInternalFieldsAndProperties(
                 typeof(CSharpCompilationOptions),
                 "AllowUnsafe",
-                "Usings");
+                "Usings",
+                "TopLevelBinderFlags");
         }
 
         [Fact]
@@ -356,12 +360,14 @@ private static CSharpCompilationOptions CreateCSharpCompilationOptions()
             StrongNameProvider strongNameProvider = new DesktopStrongNameProvider();
             MetadataImportOptions metadataImportOptions = 0;
             bool reportSuppressedDiagnostics = false;
+            var topLevelBinderFlags = BinderFlags.None;
+            var publicSign = false;
+
             return new CSharpCompilationOptions(OutputKind.ConsoleApplication, reportSuppressedDiagnostics, moduleName, mainTypeName, scriptClassName, usings,
                 optimizationLevel, checkOverflow, allowUnsafe, cryptoKeyContainer, cryptoKeyFile, cryptoPublicKey, delaySign,
                 platform, generalDiagnosticOption, warningLevel, specificDiagnosticOptions,
                 concurrentBuild, deterministic, extendedCustomDebugInformation, debugPlusMode, xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver,
-                assemblyIdentityComparer, strongNameProvider, metadataImportOptions,
-                publicSign: false);
+                assemblyIdentityComparer, strongNameProvider, metadataImportOptions, publicSign, topLevelBinderFlags);
         }
 
         private sealed class MetadataReferenceResolverWithEquality : MetadataReferenceResolver

src/Compilers/CSharp/Test/Symbol/Symbols/TypeTests.cs

@@ -777,6 +777,53 @@ static void Main()
                 Diagnostic(ErrorCode.ERR_SameFullNameAggAgg, "N.C").WithArguments("A, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", "N.C", "B, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null"));
         }
 
+        [WorkItem(320, "https://github.com/dotnet/cli/issues/320")]
+        [Fact]
+        public void DuplicateCoreFxPublicTypes()
+        {
+            var sysConsoleSrc = @"
+[assembly: System.Reflection.AssemblyVersion(""4.0.0.0"")]
+
+namespace System
+{
+    public static class Console 
+    {
+        public static void Foo() {} 
+    }
+}
+";
+            var sysConsoleRef = CreateCompilation(
+                sysConsoleSrc,
+                new[] { SystemRuntimePP7Ref },
+                TestOptions.ReleaseDll.WithCryptoPublicKey(TestResources.TestKeys.PublicKey_b03f5f7f11d50a3a),
+                assemblyName: "System.Console").EmitToImageReference();
+
+            var mainSrc = @"
+System.Console.Foo(); 
+Foo();
+";
+
+            var main1 = CreateCompilation(
+                new[] { Parse(mainSrc, options: TestOptions.Script) },
+                new[] { MscorlibRef_v46, sysConsoleRef },
+                TestOptions.ReleaseDll.WithUsings("System.Console"));
+
+            main1.VerifyDiagnostics(
+                // error CS0433: The type 'Console' exists in both 'System.Console, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' and 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
+                Diagnostic(ErrorCode.ERR_SameFullNameAggAgg).WithArguments("System.Console, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", "System.Console", "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"),
+                // (1,9): error CS0433: The type 'Console' exists in both 'System.Console, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' and 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
+                Diagnostic(ErrorCode.ERR_SameFullNameAggAgg, "System.Console").WithArguments("System.Console, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", "System.Console", "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"),
+                // (2,9): error CS0103: The name 'Foo' does not exist in the current context
+                Diagnostic(ErrorCode.ERR_NameNotInContext, "Foo").WithArguments("Foo"));
+
+            var main2 = CreateCompilation(
+                new[] { Parse(mainSrc, options: TestOptions.Script) }, 
+                new[] { MscorlibRef_v46, sysConsoleRef, SystemRuntimeFacadeRef }, 
+                TestOptions.ReleaseDll.WithUsings("System.Console").WithTopLevelBinderFlags(BinderFlags.IgnoreCorLibraryDuplicatedTypes));
+
+            main2.VerifyDiagnostics();
+        }
+
         [Fact]
         public void SimpleGeneric()
         {

src/ExpressionEvaluator/CSharp/Source/ExpressionCompiler/CompilationContext.cs

@@ -641,14 +641,7 @@ private static Binder CreateBinderChain(
                 @namespace = @namespace.ContainingNamespace;
             }
 
-            var binder = (new BuckStopsHereBinder(compilation)).WithAdditionalFlags(
-                BinderFlags.SuppressObsoleteChecks |
-                BinderFlags.IgnoreAccessibility |
-                BinderFlags.UnsafeRegion |
-                BinderFlags.UncheckedRegion |
-                BinderFlags.AllowManagedAddressOf |
-                BinderFlags.AllowAwaitInUnsafeContext |
-                BinderFlags.IgnoreCorLibraryDuplicatedTypes);
+            Binder binder = new BuckStopsHereBinder(compilation);
             var hasImports = !importRecordGroups.IsDefaultOrEmpty;
             var numImportStringGroups = hasImports ? importRecordGroups.Length : 0;
             var currentStringGroup = numImportStringGroups - 1;

src/ExpressionEvaluator/CSharp/Source/ExpressionCompiler/CompilationExtensions.cs

@@ -127,6 +127,14 @@ private static CSharpCompilation ToCompilation(this ImmutableArray<MetadataRefer
             platform: Platform.AnyCpu, // Platform should match PEModule.Machine, in this case I386.
             optimizationLevel: OptimizationLevel.Release,
             assemblyIdentityComparer: IdentityComparer).
-            WithMetadataImportOptions(MetadataImportOptions.All);
+            WithMetadataImportOptions(MetadataImportOptions.All).
+            WithTopLevelBinderFlags(
+                BinderFlags.SuppressObsoleteChecks |
+                BinderFlags.IgnoreAccessibility |
+                BinderFlags.UnsafeRegion |
+                BinderFlags.UncheckedRegion |
+                BinderFlags.AllowManagedAddressOf |
+                BinderFlags.AllowAwaitInUnsafeContext |
+                BinderFlags.IgnoreCorLibraryDuplicatedTypes);
     }
 }

src/Scripting/CSharp/CSharpScriptCompiler.cs

@@ -64,7 +64,7 @@ public override Compilation CreateSubmission(Script script)
                     sourceReferenceResolver: script.Options.SourceResolver,
                     metadataReferenceResolver: script.Options.MetadataResolver,
                     assemblyIdentityComparer: DesktopAssemblyIdentityComparer.Default
-                ),
+                ).WithTopLevelBinderFlags(BinderFlags.IgnoreCorLibraryDuplicatedTypes),
                 previousSubmission,
                 script.ReturnType,
                 script.GlobalsType