Merge pull request #16422 from CyrusNajmabadi/parserDiagnostics36

Move syntax checking of ObjectCreationExpressions out of the parser.

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

@@ -3565,7 +3565,7 @@ private BoundExpression BindClassCreationExpression(ObjectCreationExpressionSynt
                 }
                 else if (node.Type.Kind() == SyntaxKind.TupleType)
                 {
-                    Debug.Assert(node.HasErrors, "new <tuple type> should be a syntax error");
+                    diagnostics.Add(ErrorCode.ERR_NewWithTupleTypeSyntax, node.Type.GetLocation());
                     return MakeBadExpressionForObjectCreation(node, type, boundInitializerOpt, analyzedArguments);
                 }
 

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

@@ -10414,18 +10414,12 @@ private ExpressionSyntax ParseArrayOrObjectCreationExpression()
                 if (argumentList == null && initializer == null)
                 {
                     argumentList = _syntaxFactory.ArgumentList(
-                        this.AddError(SyntaxFactory.MissingToken(SyntaxKind.OpenParenToken), ErrorCode.ERR_BadNewExpr),
+                        this.EatToken(SyntaxKind.OpenParenToken, ErrorCode.ERR_BadNewExpr),
                         default(SeparatedSyntaxList<ArgumentSyntax>),
                         SyntaxFactory.MissingToken(SyntaxKind.CloseParenToken));
                 }
 
-                var objectCreation = _syntaxFactory.ObjectCreationExpression(@new, type, argumentList, initializer);
-                if (type.Kind == SyntaxKind.TupleType)
-                {
-                    objectCreation = this.AddError(objectCreation, type, ErrorCode.ERR_NewWithTupleTypeSyntax);
-                }
-
-                return objectCreation;
+                return _syntaxFactory.ObjectCreationExpression(@new, type, argumentList, initializer);
             }
         }
 

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

@@ -2132,12 +2132,11 @@ public static void Main()
         {
             e = new base;   // CS1031, not a type
             e = new this;   // CS1031, not a type
-            e = new ();     // CS1031, too few tuple elements
         }
     }
 }
 ";
-            // TODO: this appears to be a severe regression from Dev10, which neatly reported 3 errors.
+
             ParseAndValidate(text, TestOptions.Regular,
                 // (7,21): error CS1031: Type expected
                 //             e = new base;   // CS1031, not a type
@@ -2156,17 +2155,37 @@ public static void Main()
                 Diagnostic(ErrorCode.ERR_BadNewExpr, "this").WithLocation(8, 21),
                 // (8,21): error CS1002: ; expected
                 //             e = new this;   // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_SemicolonExpected, "this").WithLocation(8, 21),
-                // (9,21): error CS8181: 'new' cannot be used with tuple type. Use a tuple literal expression instead.
-                //             e = new ();     // CS1031, too few tuple elements
-                Diagnostic(ErrorCode.ERR_NewWithTupleTypeSyntax, "()").WithLocation(9, 21),
-                // (9,22): error CS8124: Tuple must contain at least two elements.
-                //             e = new ();     // CS1031, too few tuple elements
-                Diagnostic(ErrorCode.ERR_TupleTooFewElements, ")").WithLocation(9, 22),
-                // (9,23): error CS1526: A new expression requires (), [], or {} after type
-                //             e = new ();     // CS1031, too few tuple elements
-                Diagnostic(ErrorCode.ERR_BadNewExpr, ";").WithLocation(9, 23)
-             );
+                Diagnostic(ErrorCode.ERR_SemicolonExpected, "this").WithLocation(8, 21));
+        }
+
+        [Fact]
+        public void CS1031ERR_TypeExpected02_Tuple()
+        {
+            var text = @"namespace x
+{
+    public class a
+    {
+        public static void Main()
+        {
+            var e = new ();
+        }
+    }
+}
+";
+
+            CreateCompilationWithMscorlib(text).VerifyDiagnostics(
+                // (7,26): error CS8124: Tuple must contain at least two elements.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_TupleTooFewElements, ")").WithLocation(7, 26),
+                // (7,27): error CS1526: A new expression requires (), [], or {} after type
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_BadNewExpr, ";").WithLocation(7, 27),
+                // (7,25): error CS8181: 'new' cannot be used with tuple type. Use a tuple literal expression instead.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_NewWithTupleTypeSyntax, "()").WithLocation(7, 25),
+                // (7,25): error CS8179: Predefined type 'System.ValueTuple`2' is not defined or imported
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_PredefinedValueTupleTypeNotFound, "()").WithArguments("System.ValueTuple`2").WithLocation(7, 25));
         }
 
         [Fact]
@@ -2180,7 +2199,6 @@ public static void Main()
         {
             e = new base;   // CS1031, not a type
             e = new this;   // CS1031, not a type
-            e = new ();     // CS1031, not a type
         }
     }
 }
@@ -2204,20 +2222,68 @@ public static void Main()
                 Diagnostic(ErrorCode.ERR_BadNewExpr, "this").WithLocation(8, 21),
                 // (8,21): error CS1002: ; expected
                 //             e = new this;   // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_SemicolonExpected, "this").WithLocation(8, 21),
-                // (9,21): error CS8181: 'new' cannot be used with tuple type. Use a tuple literal expression instead.
-                //             e = new ();     // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_NewWithTupleTypeSyntax, "()").WithLocation(9, 21),
-                // (9,21): error CS8059: Feature 'tuples' is not available in C# 6. Please use language version 7 or greater.
-                //             e = new ();     // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_FeatureNotAvailableInVersion6, "()").WithArguments("tuples", "7").WithLocation(9, 21),
-                // (9,22): error CS8124: Tuple must contain at least two elements.
-                //             e = new ();     // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_TupleTooFewElements, ")").WithLocation(9, 22),
-                // (9,23): error CS1526: A new expression requires (), [], or {} after type
-                //             e = new ();     // CS1031, not a type
-                Diagnostic(ErrorCode.ERR_BadNewExpr, ";").WithLocation(9, 23)
-             );
+                Diagnostic(ErrorCode.ERR_SemicolonExpected, "this").WithLocation(8, 21));
+        }
+
+        [Fact]
+        public void CS1031ERR_TypeExpected02WithCSharp6_Tuple()
+        {
+            var text = @"namespace x
+{
+    public class a
+    {
+        public static void Main()
+        {
+            var e = new ();
+        }
+    }
+}
+";
+            CreateCompilationWithMscorlib(text, parseOptions: TestOptions.Regular.WithLanguageVersion(LanguageVersion.CSharp6)).VerifyDiagnostics(
+                // (7,25): error CS8059: Feature 'tuples' is not available in C# 6.  Please use language version 7 or greater.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_FeatureNotAvailableInVersion6, "()").WithArguments("tuples", "7").WithLocation(7, 25),
+                // (7,26): error CS8124: Tuple must contain at least two elements.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_TupleTooFewElements, ")").WithLocation(7, 26),
+                // (7,27): error CS1526: A new expression requires (), [], or {} after type
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_BadNewExpr, ";").WithLocation(7, 27),
+                // (7,25): error CS8181: 'new' cannot be used with tuple type. Use a tuple literal expression instead.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_NewWithTupleTypeSyntax, "()").WithLocation(7, 25),
+                // (7,25): error CS8179: Predefined type 'System.ValueTuple`2' is not defined or imported
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_PredefinedValueTupleTypeNotFound, "()").WithArguments("System.ValueTuple`2").WithLocation(7, 25));
+        }
+
+        [Fact]
+        public void CS1031ERR_TypeExpected02WithCSharp7_Tuple()
+        {
+            var text = @"namespace x
+{
+    public class a
+    {
+        public static void Main()
+        {
+            var e = new ();
+        }
+    }
+}
+";
+            CreateCompilationWithMscorlib(text, parseOptions: TestOptions.Regular.WithLanguageVersion(LanguageVersion.CSharp7)).VerifyDiagnostics(
+                // (7,26): error CS8124: Tuple must contain at least two elements.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_TupleTooFewElements, ")"),
+                // (7,27): error CS1526: A new expression requires (), [], or {} after type
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_BadNewExpr, ";"),
+                // (7,25): error CS8179: Predefined type 'System.ValueTuple`2' is not defined or imported
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_PredefinedValueTupleTypeNotFound, "()").WithArguments("System.ValueTuple`2"),
+                // (7,25): error CS8181: 'new' cannot be used with tuple type. Use a tuple literal expression instead.
+                //             var e = new ();
+                Diagnostic(ErrorCode.ERR_NewWithTupleTypeSyntax, "()"));
         }
 
         [WorkItem(541347, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/541347")]
@@ -5633,4 +5699,4 @@ public static void Main(string[] args)
 
         #endregion
     }
-}
+}
\ No newline at end of file