Merge pull request #16350 from CyrusNajmabadi/parserDiagnostics31

Move indexer parameter count checking out of the parser.

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

@@ -3118,7 +3118,7 @@ private ConversionOperatorDeclarationSyntax ParseConversionOperatorDeclaration(S
                 semicolon);
         }
 
-        private MemberDeclarationSyntax ParseIndexerDeclaration(
+        private IndexerDeclarationSyntax ParseIndexerDeclaration(
             SyntaxListBuilder<AttributeListSyntax> attributes,
             SyntaxListBuilder modifiers,
             TypeSyntax type,
@@ -3136,11 +3136,6 @@ private ConversionOperatorDeclarationSyntax ParseConversionOperatorDeclaration(S
             }
 
             var parameterList = this.ParseBracketedParameterList();
-            // TODO: ReportExtensionMethods(parameters, retval);
-            if (parameterList.Parameters.Count == 0)
-            {
-                parameterList = this.AddErrorToLastToken(parameterList, ErrorCode.ERR_IndexerNeedsParam);
-            }
 
             AccessorListSyntax accessorList = null;
             ArrowExpressionClauseSyntax expressionBody = null;

src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertySymbol.cs

@@ -766,13 +766,19 @@ private DeclarationModifiers MakeModifiers(SyntaxTokenList modifiers, bool isExp
             return mods;
         }
 
-        private static ImmutableArray<ParameterSymbol> MakeParameters(Binder binder, SourcePropertySymbol owner, BaseParameterListSyntax parameterSyntaxOpt, DiagnosticBag diagnostics)
+        private static ImmutableArray<ParameterSymbol> MakeParameters(
+            Binder binder, SourcePropertySymbol owner, BaseParameterListSyntax parameterSyntaxOpt, DiagnosticBag diagnostics)
         {
             if (parameterSyntaxOpt == null)
             {
                 return ImmutableArray<ParameterSymbol>.Empty;
             }
 
+            if (parameterSyntaxOpt.Parameters.Count < 1)
+            {
+                diagnostics.Add(ErrorCode.ERR_IndexerNeedsParam, parameterSyntaxOpt.GetLastToken().GetLocation());
+            }
+
             SyntaxToken arglistToken;
             var parameters = ParameterHelpers.MakeParameters(
                 binder, owner, parameterSyntaxOpt, out arglistToken,

src/Compilers/CSharp/Test/Syntax/Parsing/ParserErrorMessageTests.cs

@@ -3802,7 +3802,10 @@ public class MyClass {
 }
 ";
 
-            ParseAndValidate(test, Diagnostic(ErrorCode.ERR_IndexerNeedsParam, "]"));
+            CreateCompilationWithMscorlib(test).VerifyDiagnostics(
+                // (4,14): error CS1551: Indexers must have at least one parameter
+                //     int this[] {
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam, "]").WithLocation(4, 14));
         }
 
         [Fact]

src/Compilers/CSharp/Test/Syntax/Parsing/ParsingErrorRecoveryTests.cs

@@ -1870,11 +1870,27 @@ public void TestEndBraceAfterIndexerParameterStart()
             var agg = (TypeDeclarationSyntax)file.Members[0];
             Assert.Equal(1, agg.Members.Count);
             Assert.Equal(SyntaxKind.IndexerDeclaration, agg.Members[0].Kind());
-            Assert.Equal(4, file.Errors().Length);
-            Assert.Equal((int)ErrorCode.ERR_IndexerNeedsParam, file.Errors()[0].Code);
-            Assert.Equal((int)ErrorCode.ERR_SyntaxError, file.Errors()[1].Code);
-            Assert.Equal((int)ErrorCode.ERR_LbraceExpected, file.Errors()[2].Code);
-            Assert.Equal((int)ErrorCode.ERR_RbraceExpected, file.Errors()[3].Code);
+            Assert.Equal(3, file.Errors().Length);
+            Assert.Equal((int)ErrorCode.ERR_SyntaxError, file.Errors()[0].Code);
+            Assert.Equal((int)ErrorCode.ERR_LbraceExpected, file.Errors()[1].Code);
+            Assert.Equal((int)ErrorCode.ERR_RbraceExpected, file.Errors()[2].Code);
+
+            CreateCompilationWithMscorlib(text).VerifyDiagnostics(
+                // (1,21): error CS1003: Syntax error, ']' expected
+                // class c { int this[ }
+                Diagnostic(ErrorCode.ERR_SyntaxError, "}").WithArguments("]", "}").WithLocation(1, 21),
+                // (1,21): error CS1514: { expected
+                // class c { int this[ }
+                Diagnostic(ErrorCode.ERR_LbraceExpected, "}").WithLocation(1, 21),
+                // (1,22): error CS1513: } expected
+                // class c { int this[ }
+                Diagnostic(ErrorCode.ERR_RbraceExpected, "").WithLocation(1, 22),
+                // (1,15): error CS0548: 'c.this': property or indexer must have at least one accessor
+                // class c { int this[ }
+                Diagnostic(ErrorCode.ERR_PropertyWithNoAccessors, "this").WithArguments("c.this").WithLocation(1, 15),
+                // (1,19): error CS1551: Indexers must have at least one parameter
+                // class c { int this[ }
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam, "[").WithLocation(1, 19));
         }
 
         [Fact]
@@ -1968,9 +1984,19 @@ public void TestGarbageAfterIndexerParameterStart()
             var agg = (TypeDeclarationSyntax)file.Members[0];
             Assert.Equal(1, agg.Members.Count);
             Assert.Equal(SyntaxKind.IndexerDeclaration, agg.Members[0].Kind());
-            Assert.Equal(2, file.Errors().Length);
-            Assert.Equal((int)ErrorCode.ERR_IndexerNeedsParam, file.Errors()[0].Code);
-            Assert.Equal((int)ErrorCode.ERR_UnexpectedCharacter, file.Errors()[1].Code);
+            Assert.Equal(1, file.Errors().Length);
+            Assert.Equal((int)ErrorCode.ERR_UnexpectedCharacter, file.Errors()[0].Code);
+
+            CreateCompilationWithMscorlib(text).VerifyDiagnostics(
+                // (1,21): error CS1056: Unexpected character '$'
+                // class c { int this[ $ ] { } }
+                Diagnostic(ErrorCode.ERR_UnexpectedCharacter, "").WithArguments("$").WithLocation(1, 21),
+                // (1,15): error CS0548: 'c.this': property or indexer must have at least one accessor
+                // class c { int this[ $ ] { } }
+                Diagnostic(ErrorCode.ERR_PropertyWithNoAccessors, "this").WithArguments("c.this").WithLocation(1, 15),
+                // (1,23): error CS1551: Indexers must have at least one parameter
+                // class c { int this[ $ ] { } }
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam, "]").WithLocation(1, 23));
         }
 
         [Fact]
@@ -2041,11 +2067,27 @@ public void TestMethodAfterIndexerParameterStart()
             Assert.Equal(2, agg.Members.Count);
             Assert.Equal(SyntaxKind.IndexerDeclaration, agg.Members[0].Kind());
             Assert.Equal(SyntaxKind.MethodDeclaration, agg.Members[1].Kind());
-            Assert.Equal(4, file.Errors().Length);
-            Assert.Equal((int)ErrorCode.ERR_IndexerNeedsParam, file.Errors()[0].Code);
-            Assert.Equal((int)ErrorCode.ERR_SyntaxError, file.Errors()[1].Code);
-            Assert.Equal((int)ErrorCode.ERR_LbraceExpected, file.Errors()[2].Code);
-            Assert.Equal((int)ErrorCode.ERR_RbraceExpected, file.Errors()[3].Code);
+            Assert.Equal(3, file.Errors().Length);
+            Assert.Equal((int)ErrorCode.ERR_SyntaxError, file.Errors()[0].Code);
+            Assert.Equal((int)ErrorCode.ERR_LbraceExpected, file.Errors()[1].Code);
+            Assert.Equal((int)ErrorCode.ERR_RbraceExpected, file.Errors()[2].Code);
+
+            CreateCompilationWithMscorlib(text).VerifyDiagnostics(
+                // (1,21): error CS1003: Syntax error, ']' expected
+                // class c { int this[ public void m() { } }
+                Diagnostic(ErrorCode.ERR_SyntaxError, "public").WithArguments("]", "public").WithLocation(1, 21),
+                // (1,21): error CS1514: { expected
+                // class c { int this[ public void m() { } }
+                Diagnostic(ErrorCode.ERR_LbraceExpected, "public").WithLocation(1, 21),
+                // (1,21): error CS1513: } expected
+                // class c { int this[ public void m() { } }
+                Diagnostic(ErrorCode.ERR_RbraceExpected, "public").WithLocation(1, 21),
+                // (1,15): error CS0548: 'c.this': property or indexer must have at least one accessor
+                // class c { int this[ public void m() { } }
+                Diagnostic(ErrorCode.ERR_PropertyWithNoAccessors, "this").WithArguments("c.this").WithLocation(1, 15),
+                // (1,19): error CS1551: Indexers must have at least one parameter
+                // class c { int this[ public void m() { } }
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam, "[").WithLocation(1, 19));
         }
 
         [Fact]
@@ -6679,9 +6721,6 @@ public void ColonColonInExplicitInterfaceMember()
                 // (2,4): error CS1003: Syntax error, '.' expected
                 // _ _::this
                 Diagnostic(ErrorCode.ERR_SyntaxError, "::").WithArguments(".", "::"),
-                // (3,1): error CS1551: Indexers must have at least one parameter
-                // 
-                Diagnostic(ErrorCode.ERR_IndexerNeedsParam, ""),
                 // (2,10): error CS1003: Syntax error, '[' expected
                 // _ _::this
                 Diagnostic(ErrorCode.ERR_SyntaxError, "").WithArguments("[", ""),
@@ -6694,6 +6733,37 @@ public void ColonColonInExplicitInterfaceMember()
                 // (2,10): error CS1513: } expected
                 // _ _::this
                 Diagnostic(ErrorCode.ERR_RbraceExpected, ""));
+
+            CreateCompilationWithMscorlib(text).VerifyDiagnostics(
+                // (2,4): error CS1003: Syntax error, '.' expected
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_SyntaxError, "::").WithArguments(".", "::").WithLocation(2, 4),
+                // (2,10): error CS1003: Syntax error, '[' expected
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_SyntaxError, "").WithArguments("[", "").WithLocation(2, 10),
+                // (2,10): error CS1003: Syntax error, ']' expected
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_SyntaxError, "").WithArguments("]", "").WithLocation(2, 10),
+                // (2,10): error CS1514: { expected
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_LbraceExpected, "").WithLocation(2, 10),
+                // (2,10): error CS1513: } expected
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_RbraceExpected, "").WithLocation(2, 10),
+                // (2,3): error CS0246: The type or namespace name '_' could not be found (are you missing a using directive or an assembly reference?)
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound, "_").WithArguments("_").WithLocation(2, 3),
+                // (2,1): error CS0246: The type or namespace name '_' could not be found (are you missing a using directive or an assembly reference?)
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_SingleTypeNameNotFound, "_").WithArguments("_").WithLocation(2, 1),
+                // error CS1551: Indexers must have at least one parameter
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam).WithLocation(1, 1),
+                // (2,3): error CS0538: '_' in explicit interface declaration is not an interface
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_ExplicitInterfaceImplementationNotInterface, "_").WithArguments("_").WithLocation(2, 3),
+                // (2,6): error CS0548: '<invalid-global-code>.this': property or indexer must have at least one accessor
+                // _ _::this
+                Diagnostic(ErrorCode.ERR_PropertyWithNoAccessors, "this").WithArguments("<invalid-global-code>.this").WithLocation(2, 6));
         }
 
         [WorkItem(649806, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/649806")]

src/Compilers/CSharp/Test/Syntax/Parsing/ScriptParsingTests.cs

@@ -1571,9 +1571,30 @@ public void Error_IndexerDefinition()
                 new ErrorDescription { Code = 1001, Line = 1, Column = 13 },
                 new ErrorDescription { Code = 1003, Line = 1, Column = 13 },
                 new ErrorDescription { Code = 1003, Line = 1, Column = 17 },
-                new ErrorDescription { Code = 1551, Line = 1, Column = 17 },
                 new ErrorDescription { Code = 1514, Line = 1, Column = 17 },
                 new ErrorDescription { Code = 1513, Line = 1, Column = 17 });
+
+            CreateCompilationWithMscorlib(test).VerifyDiagnostics(
+                // (1,13): error CS1003: Syntax error, '[' expected
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_SyntaxError, "=").WithArguments("[", "=").WithLocation(1, 13),
+                // (1,13): error CS1001: Identifier expected
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_IdentifierExpected, "=").WithLocation(1, 13),
+                // (1,17): error CS1003: Syntax error, ']' expected
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_SyntaxError, "").WithArguments("]", "").WithLocation(1, 17),
+                // (1,17): error CS1514: { expected
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_LbraceExpected, "").WithLocation(1, 17),
+                // (1,17): error CS1513: } expected
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_RbraceExpected, "").WithLocation(1, 17),
+                // (1,8): error CS0548: '<invalid-global-code>.this': property or indexer must have at least one accessor
+                // string this ="";
+                Diagnostic(ErrorCode.ERR_PropertyWithNoAccessors, "this").WithArguments("<invalid-global-code>.this").WithLocation(1, 8),
+                // error CS1551: Indexers must have at least one parameter
+                Diagnostic(ErrorCode.ERR_IndexerNeedsParam).WithLocation(1, 1));
         }
 
         #endregion