Enable feature flag for local functions

src/Compilers/CSharp/Portable/CSharpResources.Designer.cs

@@ -8999,6 +8999,15 @@ internal class CSharpResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to local functions.
+        /// </summary>
+        internal static string IDS_FeatureLocalFunctions {
+            get {
+                return ResourceManager.GetString("IDS_FeatureLocalFunctions", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to module as an attribute target specifier.
         /// </summary>

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -4599,6 +4599,9 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="IDS_AwaitInCatchAndFinally" xml:space="preserve">
     <value>await in catch blocks and finally blocks</value>
   </data>
+  <data name="IDS_FeatureLocalFunctions" xml:space="preserve">
+    <value>local functions</value>
+  </data>
   <data name="ERR_UnescapedCurly" xml:space="preserve">
     <value>A '{0}' character must be escaped (by doubling) in an interpolated string.</value>
   </data>

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

@@ -112,6 +112,7 @@ internal enum MessageID
         IDS_OperationCausedStackOverflow = MessageBase + 12703,
         IDS_AwaitInCatchAndFinally = MessageBase + 12704,
 
+        IDS_FeatureLocalFunctions = MessageBase + 12705,
     }
 
     // Message IDs may refer to strings that need to be localized.
@@ -149,6 +150,9 @@ internal static string RequiredFeature(this MessageID feature)
         {
             switch (feature)
             {
+                case MessageID.IDS_FeatureLocalFunctions:
+                    return "localFunctions";
+
                 default:
                     return null;
             }

src/Compilers/CSharp/Portable/Parser/LanguageParser.cs

@@ -7938,8 +7938,9 @@ private StatementSyntax ParseLocalDeclarationStatement()
             try
             {
                 this.ParseDeclarationModifiers(mods);
+                var allowLocalFunctions = IsFeatureEnabled(MessageID.IDS_FeatureLocalFunctions);
                 LocalFunctionStatementSyntax localFunction;
-                this.ParseDeclaration(out type, variables, true, mods.ToTokenList(), out localFunction);
+                this.ParseDeclaration(out type, variables, allowLocalFunctions, mods.ToTokenList(), out localFunction);
                 if (localFunction != null)
                 {
                     Debug.Assert(variables.Count == 0);

src/Compilers/CSharp/Test/Semantic/Diagnostics/DiagnosticAnalyzerTests.AllInOne.cs

@@ -26,7 +26,7 @@ public void DiagnosticAnalyzerAllInOne()
             symbolKindsWithNoCodeBlocks.Add(SymbolKind.NamedType);
 
             var analyzer = new CSharpTrackingDiagnosticAnalyzer();
-            CreateCompilationWithMscorlib45(source, parseOptions: TestOptions.Regular).VerifyAnalyzerDiagnostics(new[] { analyzer });
+            CreateExperimentalCompilationWithMscorlib45(source).VerifyAnalyzerDiagnostics(new[] { analyzer });
             analyzer.VerifyAllAnalyzerMembersWereCalled();
             analyzer.VerifyAnalyzeSymbolCalledForAllSymbolKinds();
             analyzer.VerifyAnalyzeNodeCalledForAllSyntaxKinds();
@@ -85,7 +85,7 @@ public class C
         [WorkItem(759)]
         public void AnalyzerDriverIsSafeAgainstAnalyzerExceptions()
         {
-            var compilation = CreateCompilationWithMscorlib45(TestResource.AllInOneCSharpCode, parseOptions: TestOptions.Regular);
+            var compilation = CreateExperimentalCompilationWithMscorlib45(TestResource.AllInOneCSharpCode);
             ThrowingDiagnosticAnalyzer<SyntaxKind>.VerifyAnalyzerEngineIsSafeAgainstExceptions(analyzer =>
                 compilation.GetAnalyzerDiagnostics(new[] { analyzer }, null, logAnalyzerExceptionAsDiagnostics: true));
         }
@@ -99,7 +99,7 @@ public void AnalyzerOptionsArePassedToAllAnalyzers()
                 new[] { new TestAdditionalText("myfilepath", text) }.ToImmutableArray<AdditionalText>()
             );
 
-            var compilation = CreateCompilationWithMscorlib45(TestResource.AllInOneCSharpCode, parseOptions: TestOptions.Regular);
+            var compilation = CreateExperimentalCompilationWithMscorlib45(TestResource.AllInOneCSharpCode);
             var analyzer = new OptionsDiagnosticAnalyzer<SyntaxKind>(options);
             compilation.GetAnalyzerDiagnostics(new[] { analyzer }, options);
             analyzer.VerifyAnalyzerOptions();

src/Compilers/CSharp/Test/Semantic/Semantics/LocalFunctionTests.cs

@@ -7,6 +7,8 @@ namespace Microsoft.CodeAnalysis.CSharp.UnitTests
 {
     public class LocalFunctionTests : CSharpTestBase
     {
+        private readonly CSharpParseOptions _parseOptions = TestOptions.Regular.WithFeatures(new SmallDictionary<string, string> { { "localFunctions", "true" } });
+
         [Fact]
         public void EndToEnd()
         {
@@ -25,7 +27,8 @@ void Local()
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 Hello, world!
 ");
         }
@@ -45,7 +48,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -83,7 +87,8 @@ void NamedOptional(int x = 2)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 2
 2
@@ -137,7 +142,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 2
 ");
@@ -165,7 +171,8 @@ void Local2()
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 2
 ");
@@ -196,7 +203,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 1
 2
 ");
@@ -234,7 +242,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 6
 ");
         }
@@ -267,7 +276,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -296,7 +306,8 @@ void Foo(int depth)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -328,7 +339,8 @@ void Bar(int depth2)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -368,7 +380,8 @@ IEnumerator LocalEnumerator()
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 2
 2
@@ -395,7 +408,9 @@ async Task<int> Local()
     }
 }
 ";
-            var compilation = CreateCompilationWithMscorlib45(source, options: new CSharpCompilationOptions(OutputKind.ConsoleApplication));
+            var compilation = CreateCompilationWithMscorlib45(source,
+                options: new CSharpCompilationOptions(OutputKind.ConsoleApplication),
+                parseOptions: _parseOptions);
             var comp = CompileAndVerify(compilation, expectedOutput: @"
 2
 ");
@@ -421,7 +436,9 @@ async Task<int> Local(int x)
     }
 }
 ";
-            var compilation = CreateCompilationWithMscorlib45(source, options: new CSharpCompilationOptions(OutputKind.ConsoleApplication));
+            var compilation = CreateCompilationWithMscorlib45(source,
+                options: new CSharpCompilationOptions(OutputKind.ConsoleApplication),
+                parseOptions: _parseOptions);
             var comp = CompileAndVerify(compilation, expectedOutput: @"
 2
 ");
@@ -480,7 +497,8 @@ static void Main(string[] args)
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -509,7 +527,8 @@ void Local()
     }
 }
 ";
-            var comp = CompileAndVerify(source, expectedOutput: @"
+            var comp = CreateCompilationWithMscorlib(source, options: TestOptions.ReleaseExe, parseOptions: _parseOptions);
+            var verify = CompileAndVerify(comp, expectedOutput: @"
 2
 ");
         }
@@ -531,7 +550,7 @@ void Local1()
 }
 ";
             var option = TestOptions.ReleaseExe.WithWarningLevel(0);
-            CreateCompilationWithMscorlibAndSystemCore(source, options: option).VerifyDiagnostics(
+            CreateCompilationWithMscorlibAndSystemCore(source, options: option, parseOptions: _parseOptions).VerifyDiagnostics(
     // (9,22): error CS1002: ; expected
     //         void Local1()
     Diagnostic(ErrorCode.ERR_SemicolonExpected, "").WithLocation(9, 22),
@@ -565,7 +584,7 @@ IEnumerable<int> Local(ref int x)
 }
 ";
             var option = TestOptions.ReleaseExe.WithWarningLevel(0);
-            CreateCompilationWithMscorlibAndSystemCore(source, options: option).VerifyDiagnostics(
+            CreateCompilationWithMscorlibAndSystemCore(source, options: option, parseOptions: _parseOptions).VerifyDiagnostics(
     // (9,40): error CS1623: Iterators cannot have ref or out parameters
     //         IEnumerable<int> Local(ref int x)
     Diagnostic(ErrorCode.ERR_BadIteratorArgType, "x").WithLocation(9, 40)
@@ -592,7 +611,7 @@ IEnumerable<int> Local(__arglist)
 }
 ";
             var option = TestOptions.ReleaseExe.WithWarningLevel(0);
-            CreateCompilationWithMscorlibAndSystemCore(source, options: option).VerifyDiagnostics(
+            CreateCompilationWithMscorlibAndSystemCore(source, options: option, parseOptions: _parseOptions).VerifyDiagnostics(
     // (9,26): error CS1636: __arglist is not allowed in the parameter list of iterators
     //         IEnumerable<int> Local(__arglist)
     Diagnostic(ErrorCode.ERR_VarargsIterator, "Local").WithLocation(9, 26)
@@ -616,7 +635,7 @@ static void Main(string[] args)
 }
 ";
             var option = TestOptions.ReleaseExe.WithWarningLevel(0);
-            CreateCompilationWithMscorlibAndSystemCore(source, options: option).VerifyDiagnostics(
+            CreateCompilationWithMscorlibAndSystemCore(source, options: option, parseOptions: _parseOptions).VerifyDiagnostics(
     // (9,27): error CS0841: Cannot use local variable 'Local' before it is declared
     //         Console.WriteLine(Local());
     Diagnostic(ErrorCode.ERR_VariableUsedBeforeDeclaration, "Local").WithArguments("Local").WithLocation(9, 27)

src/Compilers/CSharp/Test/Syntax/Syntax/SyntaxAnnotationTests.cs

@@ -125,7 +125,7 @@ public void TestCopyAnnotationOfZeroLengthToSyntaxTrivia()
         public void TestMissingAnnotationsOnNodesOrTokens()
         {
             SyntaxAnnotation annotation = new SyntaxAnnotation();
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             var matchingNodesOrTokens = tree.GetCompilationUnitRoot().GetAnnotatedNodesAndTokens(annotation);
             Assert.Empty(matchingNodesOrTokens);
@@ -135,7 +135,7 @@ public void TestMissingAnnotationsOnNodesOrTokens()
         public void TestMissingAnnotationsOnTrivia()
         {
             SyntaxAnnotation annotation = new SyntaxAnnotation();
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             var matchingTrivia = tree.GetCompilationUnitRoot().GetAnnotatedTrivia(annotation);
             Assert.Empty(matchingTrivia);
@@ -298,7 +298,7 @@ public void TestIfNodeHasAnnotations()
         [Fact]
         public void TestCSharpAllInOne()
         {
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             TestAnnotation(tree);
         }
@@ -306,7 +306,7 @@ public void TestCSharpAllInOne()
         [Fact]
         public void TestCSharpAllInOneRandom()
         {
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             TestRandomAnnotations(tree);
         }
@@ -314,7 +314,7 @@ public void TestCSharpAllInOneRandom()
         [Fact]
         public void TestCSharpAllInOneManyRandom()
         {
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             TestManyRandomAnnotations(tree);
         }
@@ -322,7 +322,7 @@ public void TestCSharpAllInOneManyRandom()
         [Fact]
         public void TestCSharpAllInOneTrivia()
         {
-            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             TestTriviaAnnotation(tree);
         }
@@ -330,8 +330,8 @@ public void TestCSharpAllInOneTrivia()
         [Fact]
         public void TestCopyAnnotations1()
         {
-            var tree1 = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
-            var tree2 = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.Regular);
+            var tree1 = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
+            var tree2 = SyntaxFactory.ParseSyntaxTree(_allInOneCSharpCode, options: Test.Utilities.TestOptions.ExperimentalParseOptions);
 
             TestCopyAnnotations(tree1, tree2);
         }

src/Compilers/Test/Utilities/CSharp/TestOptions.cs

@@ -15,7 +15,7 @@ public static class TestOptions
         public static readonly CSharpParseOptions Regular = new CSharpParseOptions(kind: SourceCodeKind.Regular, documentationMode: DocumentationMode.None);
         public static readonly CSharpParseOptions RegularWithDocumentationComments = new CSharpParseOptions(kind: SourceCodeKind.Regular, documentationMode: DocumentationMode.Diagnose);
 
-        private static readonly SmallDictionary<string, string> s_experimentalFeatures = new SmallDictionary<string, string>(); // no experimental features to enable
+        private static readonly SmallDictionary<string, string> s_experimentalFeatures = new SmallDictionary<string, string> { { "localFunctions", "true" } };
         public static readonly CSharpParseOptions ExperimentalParseOptions =
             new CSharpParseOptions(kind: SourceCodeKind.Regular, documentationMode: DocumentationMode.None, languageVersion: LanguageVersion.CSharp6).WithFeatures(s_experimentalFeatures);
 

src/Test/Utilities/TestResource.Designer.cs

 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.0
+//     Runtime Version:4.0.30319.42000
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.

src/Test/Utilities/TestResource.resx

@@ -196,6 +196,10 @@ namespace My
                 var s2 = $@"x {1 , -2 :d}";
             }
 
+            int LocalFunction()
+            {
+            }
+
 #if DEBUG
       Console.WriteLine(export.iefSupplied.command);
 #endif