Merge pull request #1106 from VSadov/parameterlessVB

Restored requirement for struct constructors to always have formal param...

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

@@ -6703,15 +6703,6 @@ internal class CSharpResources {
             }
         }
         
-        /// <summary>
-        ///   Looks up a localized string similar to Parameterless instance constructors in structs must be public.
-        /// </summary>
-        internal static string ERR_ParameterlessStructCtorsMustBePublic {
-            get {
-                return ResourceManager.GetString("ERR_ParameterlessStructCtorsMustBePublic", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   Looks up a localized string similar to Parameter not valid for the specified unmanaged type..
         /// </summary>
@@ -9098,15 +9089,6 @@ internal class CSharpResources {
             }
         }
         
-        /// <summary>
-        ///   Looks up a localized string similar to struct instance parameterless constructors.
-        /// </summary>
-        internal static string IDS_FeatureStructParameterlessConstructors {
-            get {
-                return ResourceManager.GetString("IDS_FeatureStructParameterlessConstructors", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   Looks up a localized string similar to switch on boolean type.
         /// </summary>

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -1550,9 +1550,6 @@ If such a class is used as a base class and if the deriving class defines a dest
   <data name="ERR_EnumsCantContainDefaultConstructor" xml:space="preserve">
     <value>Enums cannot contain explicit parameterless constructors</value>
   </data>
-  <data name="ERR_ParameterlessStructCtorsMustBePublic" xml:space="preserve">
-    <value>Parameterless instance constructors in structs must be public</value>
-  </data>
   <data name="ERR_CantOverrideBogusMethod" xml:space="preserve">
     <value>'{0}': cannot override '{1}' because it is not supported by the language</value>
   </data>
@@ -4553,9 +4550,6 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="IDS_FeatureDictionaryInitializer" xml:space="preserve">
     <value>dictionary initializer</value>
   </data>
-  <data name="IDS_FeatureStructParameterlessConstructors" xml:space="preserve">
-    <value>struct instance parameterless constructors</value>
-  </data>
   <data name="ERR_UnclosedExpressionHole" xml:space="preserve">
     <value>Missing close delimiter '}' for interpolated expression started with '{'.</value>
   </data>

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

@@ -1289,7 +1289,7 @@ internal enum ErrorCode
         ERR_NullPropagatingOpInExpressionTree = 8072,
         WRN_NubExprIsConstBool2 = 8073,
         ERR_DictionaryInitializerInExpressionTree = 8074,
-        ERR_ParameterlessStructCtorsMustBePublic = 8075,
+        // available: 8075,
         ERR_UnclosedExpressionHole = 8076,
         ERR_SingleLineCommentInExpressionHole = 8077,
         ERR_InsufficientStack = 8078,

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

@@ -101,7 +101,7 @@ internal enum MessageID
         // IDS_VersionExperimental = MessageBase + 12694,
         IDS_FeatureNameof = MessageBase + 12695,
         IDS_FeatureDictionaryInitializer = MessageBase + 12696,
-        IDS_FeatureStructParameterlessConstructors = MessageBase + 12697,
+        // available: MessageBase + 12697,
 
         IDS_LogoLine1 = MessageBase + 12698,
         IDS_LogoLine2 = MessageBase + 12699,
@@ -158,7 +158,6 @@ internal static LanguageVersion RequiredVersion(this MessageID feature)
                 case MessageID.IDS_FeatureExpressionBodiedIndexer:
                 case MessageID.IDS_FeatureNameof:
                 case MessageID.IDS_FeatureDictionaryInitializer:
-                case MessageID.IDS_FeatureStructParameterlessConstructors:
                 case MessageID.IDS_FeatureUsingStatic:
                 case MessageID.IDS_FeatureInterpolatedStrings:
                     return LanguageVersion.CSharp6;

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

@@ -2723,13 +2723,9 @@ private static void CheckInterfaceMember(Symbol member, DiagnosticBag diagnostic
                         {
                             diagnostics.Add(ErrorCode.ERR_EnumsCantContainDefaultConstructor, m.Locations[0]);
                         }
-                        else if (m.DeclaredAccessibility != Accessibility.Public)
-                        {
-                            diagnostics.Add(ErrorCode.ERR_ParameterlessStructCtorsMustBePublic, m.Locations[0]);
-                        }
                         else
                         {
-                            Binder.CheckFeatureAvailability(m.Locations[0], MessageID.IDS_FeatureStructParameterlessConstructors, diagnostics);
+                            diagnostics.Add(ErrorCode.ERR_StructsCantContainDefaultConstructor, m.Locations[0]);
                         }
                     }
                 }

src/Compilers/CSharp/Test/Emit/CodeGen/CodeGenConstructorInitTests.cs

@@ -300,158 +300,6 @@ static void Main(string[] args)
             CompileAndVerify(text, expectedOutput: expectedOutput);
         }
 
-
-        [Fact]
-        public void ParameterlessConstructorStruct001()
-        {
-            var source = @"
-class C
-{
-    struct S1
-    {
-        public readonly int x;
-        public S1()
-        {
-            x = 42;
-        }
-    }
-
-    static void Main()
-    {
-        var s = new S1();
-        System.Console.WriteLine(s.x);
-    }
-}
-";
-            CompileAndVerify(source, expectedOutput: "42").
-                VerifyIL("C.S1..ctor", @"
-{
-  // Code size        9 (0x9)
-  .maxstack  2
-  IL_0000:  ldarg.0
-  IL_0001:  ldc.i4.s   42
-  IL_0003:  stfld      ""int C.S1.x""
-  IL_0008:  ret
-}
-");
-        }
-
-        [Fact]
-        public void ParameterlessConstructorStruct002()
-        {
-            var source = @"
-class C
-{
-    struct S1
-    {
-        public readonly int x;
-        public S1()
-        {
-            x = 42;
-        }
-
-        public S1(int a):this()
-        {
-        }
-    }
-
-    static void Main()
-    {
-        var s = new S1(123);
-        System.Console.WriteLine(s.x);
-    }
-}
-";
-            CompileAndVerify(source, expectedOutput: "42").
-                VerifyIL("C.S1..ctor(int)", @"
-{
-  // Code size        7 (0x7)
-  .maxstack  1
-  IL_0000:  ldarg.0
-  IL_0001:  call       ""C.S1..ctor()""
-  IL_0006:  ret
-}
-");
-        }
-
-        [Fact]
-        public void ParameterlessConstructorStruct003()
-        {
-            var source = @"
-class C
-{
-    struct S1
-    {
-        public readonly int x;
-        public S1(): this(42)
-        {
-        }
-
-        public S1(int a)
-        {
-            x = a;
-        }
-    }
-
-    static void Main()
-    {
-        var s = new S1();
-        System.Console.WriteLine(s.x);
-    }
-}
-";
-            CompileAndVerify(source, expectedOutput: "42").
-                VerifyIL("C.S1..ctor(int)", @"
-{
-  // Code size        8 (0x8)
-  .maxstack  2
-  IL_0000:  ldarg.0
-  IL_0001:  ldarg.1
-  IL_0002:  stfld      ""int C.S1.x""
-  IL_0007:  ret
-}
-").
-VerifyIL("C.S1..ctor()", @"
-{
-  // Code size        9 (0x9)
-  .maxstack  2
-  IL_0000:  ldarg.0
-  IL_0001:  ldc.i4.s   42
-  IL_0003:  call       ""C.S1..ctor(int)""
-  IL_0008:  ret
-}
-");
-        }
-
-        [Fact]
-        public void ParameterlessInstCtorInStructExprTree()
-        {
-            var source = @"
-
-using System;
-using System.Linq.Expressions;
-
-class C
-{
-    struct S1
-    {
-        public int x;
-        public S1()
-        {
-            x = 42;
-        }
-    }
-
-    static void Main()
-    {
-        Expression<Func<S1>> testExpr = () => new S1();
-        System.Console.Write(testExpr.Compile()().x);
-    }
-}
-";
-            CompileAndVerify(source, additionalRefs: new[] { ExpressionAssemblyRef }, expectedOutput: "42");
-        }
-
         [Fact]
         public void TestInitializerInCtor001()
         {
@@ -496,7 +344,7 @@ public struct S
     public int X{get;}
     public int Y{get;}
 
-    public S()
+    public S(int dummy)
     {
         X = 42;
         Y = X;
@@ -504,7 +352,7 @@ public S()
 
     public static void Main()
     {
-        S s = new S();
+        S s = new S(1);
         System.Console.WriteLine(s.Y);
     }
 }

src/Compilers/CSharp/Test/Semantic/FlowAnalysis/FlowDiagnosticTests.cs

@@ -1315,7 +1315,7 @@ struct S1
     S1 x2 { get; }
 
 
-    public Program()
+    public Program(int dummy)
     {
         x.i = 1;
         System.Console.WriteLine(x2.ii);
@@ -1364,7 +1364,7 @@ struct S1
     S1 x2 { get; set;}
 
 
-    public Program()
+    public Program(int dummy)
     {
         x.i = 1;
         System.Console.WriteLine(x2.ii);
@@ -1413,7 +1413,7 @@ struct S1
     S1 x2 { get;}
 
 
-    public Program()
+    public Program(int dummy)
     {
         x = new S1();
         x.i += 1;
@@ -1459,7 +1459,7 @@ struct S1
     S1 x2 { get;}
 
 
-    public Program()
+    public Program(int dummy)
     {
         this = default(Program);
 

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

@@ -178,6 +178,9 @@ static void Foo(S2 s = new S2())
 ";
             var comp = CreateExperimentalCompilationWithMscorlib45(source);
             comp.VerifyDiagnostics(
+    // (10,12): error CS0568: Structs cannot contain explicit parameterless constructors
+    //     public S2()
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "S2").WithLocation(10, 12),
     // (26,28): error CS1736: Default parameter value for 's' must be a compile-time constant
     //     static void Foo(S2 s = new S2())
     Diagnostic(ErrorCode.ERR_DefaultValueMustBeConstant, "new S2()").WithArguments("s").WithLocation(26, 28)

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

@@ -603,12 +603,12 @@ public struct X1
 
 ";
             CreateExperimentalCompilationWithMscorlib45(source).VerifyDiagnostics(
-    // (4,13): error CS8075: Parameterless struct constructors must be public
-    //     private X()
-    Diagnostic(ErrorCode.ERR_ParameterlessStructCtorsMustBePublic, "X").WithLocation(4, 13),
-    // (11,5): error CS8075: Parameterless struct constructors must be public
+    // (11,5): error CS0568: Structs cannot contain explicit parameterless constructors
     //     X1()
-    Diagnostic(ErrorCode.ERR_ParameterlessStructCtorsMustBePublic, "X1").WithLocation(11, 5)
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "X1").WithLocation(11, 5),
+    // (4,13): error CS0568: Structs cannot contain explicit parameterless constructors
+    //     private X()
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "X").WithLocation(4, 13)
                 );
         }
     }

src/Compilers/CSharp/Test/Symbol/Symbols/Source/PropertyTests.cs

@@ -118,12 +118,15 @@ public void M()
 }
 
 ").VerifyDiagnostics(
-    // (27,9): error CS0200: Property or indexer 'S.Ps' cannot be assigned to -- it is read only
-    //         Ps = 5;
-    Diagnostic(ErrorCode.ERR_AssgReadonlyProp, "Ps").WithArguments("S.Ps").WithLocation(27, 9),
+    // (24,12): error CS0568: Structs cannot contain explicit parameterless constructors
+    //     public S()
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "S").WithLocation(24, 12),
     // (9,9): error CS0200: Property or indexer 'C.Ps' cannot be assigned to -- it is read only
     //         Ps = 3;
     Diagnostic(ErrorCode.ERR_AssgReadonlyProp, "Ps").WithArguments("C.Ps").WithLocation(9, 9),
+    // (27,9): error CS0200: Property or indexer 'S.Ps' cannot be assigned to -- it is read only
+    //         Ps = 5;
+    Diagnostic(ErrorCode.ERR_AssgReadonlyProp, "Ps").WithArguments("S.Ps").WithLocation(27, 9),
     // (14,9): error CS0200: Property or indexer 'C.P' cannot be assigned to -- it is read only
     //         P = 10;
     Diagnostic(ErrorCode.ERR_AssgReadonlyProp, "P").WithArguments("C.P").WithLocation(14, 9),
@@ -136,6 +139,7 @@ public void M()
     // (33,9): error CS0200: Property or indexer 'S.Ps' cannot be assigned to -- it is read only
     //         S.Ps = 1;
     Diagnostic(ErrorCode.ERR_AssgReadonlyProp, "S.Ps").WithArguments("S.Ps").WithLocation(33, 9)
+
     );
         }
 

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

@@ -10100,29 +10100,6 @@ interface IA
                 );
         }
 
-        [Fact]
-        public void CS0568ERR_StructsCantContainDefaultConstructor01()
-        {
-            var text = @"namespace NS
-{
-    public struct S1
-    {
-        public S1() {}
-
-        struct S2<T>
-        {
-            S2() { }
-        }
-    }
-}
-";
-            var comp = DiagnosticsUtils.VerifyErrorsAndGetCompilationWithMscorlib(text,
-                new ErrorDescription { Code = (int)ErrorCode.ERR_ParameterlessStructCtorsMustBePublic, Line = 9, Column = 13 });
-
-            var ns = comp.SourceModule.GlobalNamespace.GetMembers("NS").Single() as NamespaceSymbol;
-            // TODO...
-        }
-
         [Fact]
         public void CS0569ERR_CantOverrideBogusMethod()
         {
@@ -10207,7 +10184,7 @@ public struct cly
         }
 
         [Fact]
-        public void InstanceCtorInsTructPre60()
+        public void CS0568ERR_StructsCantContainDefaultConstructor01()
         {
             var text = @"namespace x
 {
@@ -10224,12 +10201,12 @@ struct S2<T>
 ";
             var comp = CreateCompilationWithMscorlib(text, parseOptions: TestOptions.Regular.WithLanguageVersion(LanguageVersion.CSharp5));
             comp.VerifyDiagnostics(
-    // (5,16): error CS8026: Feature 'struct instance parameterless constructors' is not available in C# 5.  Please use language version 6 or greater.
+    // (5,16): error CS0568: Structs cannot contain explicit parameterless constructors
     //         public S1() {}
-    Diagnostic(ErrorCode.ERR_FeatureNotAvailableInVersion5, "S1").WithArguments("struct instance parameterless constructors", "6").WithLocation(5, 16),
-    // (9,13): error CS8075: Parameterless instance constructors in structs must be public
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "S1").WithLocation(5, 16),
+    // (9,13): error CS0568: Structs cannot contain explicit parameterless constructors
     //             S2() { }
-    Diagnostic(ErrorCode.ERR_ParameterlessStructCtorsMustBePublic, "S2").WithLocation(9, 13)
+    Diagnostic(ErrorCode.ERR_StructsCantContainDefaultConstructor, "S2").WithLocation(9, 13)
    );
         }
 

src/Compilers/VisualBasic/Portable/Errors/Errors.vb

@@ -1667,7 +1667,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         ERR_NullPropagatingOpInExpressionTree = 37240
         ERR_TooLongOrComplexExpression = 37241
 
-        ERR_StructParameterlessInstanceCtorMustBePublic = 37242
+        ' available: 37242
         ERR_AutoPropertyCantBeWriteOnly = 37243
 
         ERR_ExpressionDoesntHaveName = 37244

src/Compilers/VisualBasic/Portable/Symbols/Source/SourceMethodSymbol.vb

@@ -399,15 +399,8 @@ lReportErrorOnTwoTokens:
 
             If (flags And SourceMemberFlags.Shared) = 0 Then
                 If container.TypeKind = TypeKind.Structure AndAlso methodSym.ParameterCount = 0 Then
-                    If binder.Compilation.LanguageVersion < LanguageVersion.VisualBasic14 Then
-                        ' Instance constructor must have parameters.
-                        Binder.ReportDiagnostic(diagBag, syntax.NewKeyword, ERRID.ERR_NewInStruct)
-                    Else
-                        If methodSym.DeclaredAccessibility <> Accessibility.Public Then
-                            ' Instance constructor must be public.
-                            Binder.ReportDiagnostic(diagBag, syntax.NewKeyword, ERRID.ERR_StructParameterlessInstanceCtorMustBePublic)
-                        End If
-                    End If
+                    ' Instance constructor must have parameters.
+                    Binder.ReportDiagnostic(diagBag, syntax.NewKeyword, ERRID.ERR_NewInStruct)
                 End If
             End If
 

src/Compilers/VisualBasic/Portable/VBResources.Designer.vb

@@ -7693,7 +7693,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         End Property
 
         '''<summary>
-        '''  Looks up a localized string similar to The feature &apos;Parameterless Instance Constructors in Structures&apos; requires language version 14 or above..
+        '''  Looks up a localized string similar to Structures cannot declare a non-shared &apos;Sub New&apos; with no parameters..
         '''</summary>
         Friend ReadOnly Property ERR_NewInStruct() As String
             Get
@@ -9928,15 +9928,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
 
-        '''<summary>
-        '''  Looks up a localized string similar to Parameterless instance constructors in structures must be public..
-        '''</summary>
-        Friend ReadOnly Property ERR_StructParameterlessInstanceCtorMustBePublic() As String
-            Get
-                Return ResourceManager.GetString("ERR_StructParameterlessInstanceCtorMustBePublic", resourceCulture)
-            End Get
-        End Property
-
         '''<summary>
         '''  Looks up a localized string similar to Methods declared in structures cannot have &apos;Handles&apos; clauses..
         '''</summary>

src/Compilers/VisualBasic/Portable/VBResources.resx

@@ -1359,7 +1359,7 @@
     <value>Structures cannot have 'Inherits' statements.</value>
   </data>
   <data name="ERR_NewInStruct" xml:space="preserve">
-    <value>The feature 'Parameterless Instance Constructors in Structures' requires language version 14 or above.</value>
+    <value>Structures cannot declare a non-shared 'Sub New' with no parameters.</value>
   </data>
   <data name="ERR_InvalidEndGet" xml:space="preserve">
     <value>'End Get' must be preceded by a matching 'Get'.</value>
@@ -5208,9 +5208,6 @@
   <data name="ERR_NullPropagatingOpInExpressionTree" xml:space="preserve">
     <value>A null propagating operator cannot be converted into an expression tree.</value>
   </data>
-  <data name="ERR_StructParameterlessInstanceCtorMustBePublic" xml:space="preserve">
-    <value>Parameterless instance constructors in structures must be public.</value>
-  </data>
   <data name="ERR_TooLongOrComplexExpression" xml:space="preserve">
     <value>An expression is too long or complex to compile</value>
   </data>

src/Compilers/VisualBasic/Test/Emit/CodeGen/CodeGenCtorInitializers.vb

@@ -9,141 +9,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.UnitTests
     Public Class CodeGenStructCtor
         Inherits BasicTestBase
 
-        <Fact()>
-        Public Sub ParameterlessCtor001()
-            CompileAndVerify(
-<compilation>
-    <file name="a.vb">
-Imports System        
-
-Structure S1
-    Public x as integer
-    Public y as integer
-    
-    public Sub New()
-        x = 42
-    end sub
-
-    public Sub New(dummy as integer)
-    end sub
-
-end structure 
-
-Module M1
-    Sub Main()
-        dim s as new S1()
-        Console.WriteLine(s.x)
-
-        s.y = 333
-        s = new S1()
-        Console.WriteLine(s.y)
-
-        s = new S1(3)
-        Console.WriteLine(s.x)
-        Console.WriteLine(s.y)
-
-    End Sub
-End Module
-
-    </file>
-</compilation>,
-expectedOutput:=<![CDATA[
-42
-0
-0
-0
-]]>).VerifyIL("S1..ctor()",
-            <![CDATA[
-{
-  // Code size       16 (0x10)
-  .maxstack  2
-  IL_0000:  ldarg.0
-  IL_0001:  initobj    "S1"
-  IL_0007:  ldarg.0
-  IL_0008:  ldc.i4.s   42
-  IL_000a:  stfld      "S1.x As Integer"
-  IL_000f:  ret
-}
-]]>).VerifyIL("S1..ctor(Integer)",
-            <![CDATA[
-{
-  // Code size        8 (0x8)
-  .maxstack  1
-  IL_0000:  ldarg.0
-  IL_0001:  initobj    "S1"
-  IL_0007:  ret
-}
-]]>)
-        End Sub
-
-        <Fact()>
-        Public Sub ParameterlessCtor002()
-            CompileAndVerify(
-<compilation>
-    <file name="a.vb">
-Imports System        
-
-Structure S1
-    Public x as integer
-    Public y as integer
-    
-    public Sub New()
-        x = 42
-    end sub
-
-    public Sub New(dummy as integer)
-        Me.New
-    end sub
-
-end structure 
-
-Module M1
-    Sub Main()
-        dim s as new S1()
-        Console.WriteLine(s.x)
-
-        s.y = 333
-        s = new S1()
-        Console.WriteLine(s.y)
-
-        s = new S1(3)
-        Console.WriteLine(s.x)
-        Console.WriteLine(s.y)
-
-    End Sub
-End Module
-
-    </file>
-</compilation>,
-expectedOutput:=<![CDATA[
-42
-0
-42
-0
-]]>).VerifyIL("S1..ctor()",
-            <![CDATA[
-{
-  // Code size       16 (0x10)
-  .maxstack  2
-  IL_0000:  ldarg.0
-  IL_0001:  initobj    "S1"
-  IL_0007:  ldarg.0
-  IL_0008:  ldc.i4.s   42
-  IL_000a:  stfld      "S1.x As Integer"
-  IL_000f:  ret
-}
-]]>).VerifyIL("S1..ctor(Integer)",
-            <![CDATA[
-{
-  // Code size        7 (0x7)
-  .maxstack  1
-  IL_0000:  ldarg.0
-  IL_0001:  call       "Sub S1..ctor()"
-  IL_0006:  ret
-}
-]]>)
-        End Sub
-
         <Fact()>
         Public Sub ParameterlessCtor003()
             CompileAndVerify(
@@ -207,39 +72,6 @@ expectedOutput:=<![CDATA[
 ]]>)
         End Sub
 
-        <Fact()>
-        Public Sub ParameterlessCtor004()
-            Dim source =
-<compilation>
-    <file name="a.vb">
-Imports System        
-Imports System.Linq.Expressions
-
-Structure S1
-    Public x as integer
-    Public y as integer
-    
-    public Sub New()
-        x = 42
-    end sub
-end structure 
-
-Module M1
-    Sub Main()
-        Dim testExpr as Expression(of Func(of S1)) = Function()new S1()
-        System.Console.Write(testExpr.Compile()().x)
-    End Sub
-End Module
-
-    </file>
-</compilation>
-
-            Dim compilation = CreateCompilationWithMscorlibAndVBRuntimeAndReferences(source, {SystemCoreRef}, options:=TestOptions.ReleaseExe)
-
-            Dim verifier = CompileAndVerify(compilation, <![CDATA[42]]>)
-
-        End Sub
-
         <Fact()>
         Public Sub ReadOnlyAutopropInCtor001()
             CompileAndVerify(
@@ -330,14 +162,14 @@ Module Program
     Structure c1
         Public readonly Property p1 As Integer
         Public readonly Property p2 As Integer
-        Public Sub New()
+        Public Sub New(dummy as integer)
             p1 = 42
             p2 = p1
         End Sub
     End Structure
 
     Sub Main(args As String())
-        Dim c As New c1
+        Dim c As New c1(1)
         System.Console.WriteLine(c.p2)
     End Sub
 End Module
@@ -345,7 +177,7 @@ End Module
     </file>
 </compilation>,
 expectedOutput:=<![CDATA[42]]>
-            ).VerifyIL("Program.c1..ctor()",
+            ).VerifyIL("Program.c1..ctor(Integer)",
             <![CDATA[
 {
   // Code size       28 (0x1c)
@@ -450,13 +282,13 @@ expectedOutput:=<![CDATA[42]]>
 Module Program
     Structure c1
         Public readonly Property p1 As Integer
-        Public Sub New()
+        Public Sub New(dummy as integer)
             p1 += 42
         End Sub
     End Structure
 
     Sub Main(args As String())
-        Dim c As New c1
+        Dim c As New c1(1)
         System.Console.WriteLine(c.p1)
     End Sub
 End Module
@@ -464,7 +296,7 @@ End Module
     </file>
 </compilation>,
 expectedOutput:=<![CDATA[42]]>
-            ).VerifyIL("Program.c1..ctor()",
+            ).VerifyIL("Program.c1..ctor(Integer)",
             <![CDATA[
 {
   // Code size       23 (0x17)

src/Compilers/VisualBasic/Test/Emit/CodeGen/CodeGenVBCore.vb

@@ -3027,8 +3027,10 @@ End Namespace
               options:=TestOptions.ReleaseDll.WithEmbedVbCoreRuntime(False))
 
             compilation.VerifyDiagnostics(
-                                    Diagnostic(ERRID.ERR_StructCantInherit, "Inherits System.Exception"),
-                                    Diagnostic(ERRID.ERR_UseOfKeywordFromStructure1, "MyBase").WithArguments("MyBase"))
+    Diagnostic(ERRID.ERR_NewInStruct, "New").WithLocation(20, 24),
+    Diagnostic(ERRID.ERR_StructCantInherit, "Inherits System.Exception").WithLocation(19, 13),
+    Diagnostic(ERRID.ERR_UseOfKeywordFromStructure1, "MyBase").WithArguments("MyBase").WithLocation(21, 17)
+                                    )
         End Sub
 
         Private Sub AssertTypeAndItsMembersAreImplicitlyDeclared(type As NamedTypeSymbol)

src/Compilers/VisualBasic/Test/Symbol/SymbolsTests/Source/TypeTests.vb

@@ -2498,7 +2498,9 @@ End Structure
             Dim s2 = compilation.GlobalNamespace.GetTypeMembers("s2")(0)
             Assert.Equal(2, s2.InstanceConstructors.Length)
 
-            compilation.VerifyDiagnostics()
+            compilation.VerifyDiagnostics(
+                    Diagnostic(ERRID.ERR_NewInStruct, "new").WithLocation(2, 9)
+)
         End Sub
 
         <Fact, WorkItem(530171, "DevDiv")>

src/Compilers/VisualBasic/Test/Symbol/SymbolsTests/SymbolErrorTests.vb

@@ -6551,7 +6551,7 @@ BC30628: Structures cannot have 'Inherits' statements.
         ]]></file>
     </compilation>, parseOptions:=TestOptions.Regular.WithLanguageVersion(LanguageVersion.VisualBasic12))
             Dim expectedErrors1 = <errors><![CDATA[
-BC30629: The feature 'Parameterless Instance Constructors in Structures' requires language version 14 or above.
+BC30629: Structures cannot declare a non-shared 'Sub New' with no parameters.
                     Public Sub New()
                                ~~~
                  ]]></errors>
@@ -6576,7 +6576,7 @@ BC30629: The feature 'Parameterless Instance Constructors in Structures' require
         ]]></file>
     </compilation>)
             Dim expectedErrors1 = <errors><![CDATA[
-BC37242: Parameterless instance constructors in structures must be public.
+BC30629: Structures cannot declare a non-shared 'Sub New' with no parameters.
                     Private Sub New()
                                 ~~~
                  ]]></errors>