Implement Required Members for VB

src/Compilers/Test/Core/CommonTestBase.cs

@@ -14,6 +14,7 @@
 using System.Text;
 using System.Xml.Linq;
 using Microsoft.CodeAnalysis.CodeGen;
+using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Symbols.Metadata.PE;
 using Microsoft.CodeAnalysis.Emit;
 using Microsoft.CodeAnalysis.Operations;
@@ -302,9 +303,33 @@ internal static MetadataReference GetILModuleReference(string ilSource, bool pre
             IEnumerable<MetadataReference> referencedAssemblies = null,
             IEnumerable<Compilation> referencedCompilations = null)
         {
+            return CreateCSharpCompilation(assemblyName, assemblyIdentity: null, code, parseOptions, compilationOptions, referencedAssemblies, referencedCompilations);
+        }
+
+        protected CSharp.CSharpCompilation CreateCSharpCompilation(
+            AssemblyIdentity assemblyIdentity,
+            string code,
+            CSharp.CSharpParseOptions parseOptions = null,
+            CSharp.CSharpCompilationOptions compilationOptions = null,
+            IEnumerable<MetadataReference> referencedAssemblies = null,
+            IEnumerable<Compilation> referencedCompilations = null)
+        {
+            return CreateCSharpCompilation(assemblyName: null, assemblyIdentity, code, parseOptions, compilationOptions, referencedAssemblies, referencedCompilations);
+        }
+
+        private CSharp.CSharpCompilation CreateCSharpCompilation(
+            string assemblyName,
+            AssemblyIdentity assemblyIdentity,
+            string code,
+            CSharp.CSharpParseOptions parseOptions = null,
+            CSharp.CSharpCompilationOptions compilationOptions = null,
+            IEnumerable<MetadataReference> referencedAssemblies = null,
+            IEnumerable<Compilation> referencedCompilations = null)
+        {
+            Debug.Assert(assemblyName == null || assemblyIdentity == null || assemblyIdentity.Name == assemblyName);
             if (assemblyName == null)
             {
-                assemblyName = GetUniqueName();
+                assemblyName = assemblyIdentity?.Name ?? GetUniqueName();
             }
 
             if (parseOptions == null)
@@ -336,7 +361,14 @@ internal static MetadataReference GetILModuleReference(string ilSource, bool pre
 
             var tree = CSharp.SyntaxFactory.ParseSyntaxTree(SourceText.From(code, encoding: null, SourceHashAlgorithms.Default), options: parseOptions);
 
-            return CSharp.CSharpCompilation.Create(assemblyName, new[] { tree }, references, compilationOptions);
+            var compilation = CSharp.CSharpCompilation.Create(assemblyName, new[] { tree }, references, compilationOptions);
+
+            if (assemblyIdentity != null)
+            {
+                ((SourceAssemblySymbol)compilation.Assembly).lazyAssemblyIdentity = assemblyIdentity;
+            }
+
+            return compilation;
         }
 
         protected VisualBasic.VisualBasicCompilation CreateVisualBasicCompilation(

src/Compilers/Test/Utilities/VisualBasic/CompilationTestUtils.vb

@@ -947,7 +947,7 @@ Friend Module CompilationUtils
             actualLine = actualReader.ReadLine()
         End While
 
-        Assert.Equal(expectedPooledBuilder.ToStringAndFree(), actualPooledBuilder.ToStringAndFree())
+        AssertEx.Equal(expectedPooledBuilder.ToStringAndFree(), actualPooledBuilder.ToStringAndFree())
     End Sub
 
     ' There are certain cases where multiple distinct errors are

src/Compilers/Test/Utilities/VisualBasic/MockSymbols.vb

@@ -6,6 +6,7 @@ Imports System.Collections.Immutable
 Imports System.Reflection
 Imports System.Runtime.InteropServices
 Imports System.Threading
+Imports Microsoft.CodeAnalysis.Collections
 Imports Microsoft.CodeAnalysis.PooledObjects
 
 Friend Interface IMockSymbol
@@ -378,6 +379,18 @@ Friend Class MockNamedTypeSymbol
     Friend NotOverridable Overrides Function GetSynthesizedWithEventsOverrides() As IEnumerable(Of PropertySymbol)
         Return SpecializedCollections.EmptyEnumerable(Of PropertySymbol)()
     End Function
+
+    Friend Overrides ReadOnly Property AllRequiredMembers As ImmutableSegmentedDictionary(Of String, Symbol)
+        Get
+            Return ImmutableSegmentedDictionary(Of String, Symbol).Empty
+        End Get
+    End Property
+
+    Friend Overrides ReadOnly Property HasRequiredMembersError As Boolean
+        Get
+            Return False
+        End Get
+    End Property
 End Class
 
 Friend Class MockMethodSymbol
@@ -637,6 +650,12 @@ Friend Class MockMethodSymbol
     Friend Overrides Function CalculateLocalSyntaxOffset(localPosition As Integer, localTree As SyntaxTree) As Integer
         Throw ExceptionUtilities.Unreachable
     End Function
+
+    Friend Overrides ReadOnly Property HasSetsRequiredMembers As Boolean
+        Get
+            Return False
+        End Get
+    End Property
 End Class
 
 Friend Class MockModuleSymbol

src/Compilers/VisualBasic/Portable/Binding/Binder_Attributes.vb

@@ -347,6 +347,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                             End If
                         Next
 
+                        CheckRequiredMembersInObjectInitializer(methodSym, boundNamedArguments, node.Name, diagnostics)
+
                         If Not errorsReported Then
                             ' There should not be any used temporaries or copy back expressions because arguments must
                             ' be constants and they cannot be passed byref. 

src/Compilers/VisualBasic/Portable/Binding/Binder_ObjectInitializer.vb

@@ -113,6 +113,13 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                         '       Emitter will just emit 'initobj' instead of constructor call instead
 
                         '  create a simplified object creation expression
+                        Dim initializerOpt As BoundObjectInitializerExpressionBase = BindObjectCollectionOrMemberInitializer(node,
+                                                                                type0,
+                                                                                asNewVariablePlaceholderOpt,
+                                                                                diagnostics)
+
+                        CheckRequiredMembersInObjectInitializer(constructorSymbol, If(initializerOpt?.Initializers, ImmutableArray(Of BoundExpression).Empty), typeNode, diagnostics)
+
                         Return New BoundObjectCreationExpression(
                                         node,
                                         constructorSymbol,
@@ -123,10 +130,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                                                              QualificationKind.QualifiedViaTypeName)),
                                         arguments:=ImmutableArray(Of BoundExpression).Empty,
                                         defaultArguments:=BitVector.Null,
-                                        BindObjectCollectionOrMemberInitializer(node,
-                                                                                type0,
-                                                                                asNewVariablePlaceholderOpt,
-                                                                                diagnostics),
+                                        initializerOpt,
                                         type0)
                     End If
 
@@ -491,8 +495,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                                                                   children.ToImmutableAndFree(),
                                                                   type0, hasErrors:=True)
                     Else
+                        Dim constructorSymbol As MethodSymbol = DirectCast(methodResult.Candidate.UnderlyingSymbol, MethodSymbol)
+
+                        CheckRequiredMembersInObjectInitializer(constructorSymbol, If(objectInitializerExpressionOpt?.Initializers, ImmutableArray(Of BoundExpression).Empty), typeNode, diagnostics)
+
                         resultExpression = New BoundObjectCreationExpression(node,
-                                                                             DirectCast(methodResult.Candidate.UnderlyingSymbol, MethodSymbol),
+                                                                             constructorSymbol,
                                                                              constructorsGroup,
                                                                              boundArguments,
                                                                              argumentInfo.DefaultArguments,
@@ -508,6 +516,62 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Return resultExpression
         End Function
 
+        Private Shared Sub CheckRequiredMembersInObjectInitializer(
+            constructor As MethodSymbol,
+            initializers As ImmutableArray(Of BoundExpression),
+            creationSyntax As SyntaxNode,
+            diagnostics As BindingDiagnosticBag)
+
+            If constructor Is Nothing OrElse constructor.HasSetsRequiredMembers Then
+                Return
+            End If
+
+            If constructor.ContainingType.HasRequiredMembersError Then
+                ' A use-site diagnostic will be reported on the use, so we don't need to do any more checking here.
+                Return
+            End If
+
+            Dim requiredMembers = constructor.ContainingType.AllRequiredMembers
+
+            If requiredMembers.Count = 0 Then
+                Return
+            End If
+
+            Dim requiredMembersBuilder = requiredMembers.ToBuilder()
+
+            If Not initializers.IsDefaultOrEmpty Then
+                For Each initializer In initializers
+                    Dim assignmentOperator = TryCast(initializer, BoundAssignmentOperator)
+                    If assignmentOperator Is Nothing Then
+                        Continue For
+                    End If
+
+                    Dim memberSymbol As Symbol = If(
+                        DirectCast(TryCast(assignmentOperator.Left, BoundPropertyAccess)?.PropertySymbol, Symbol),
+                        TryCast(assignmentOperator.Left, BoundFieldAccess)?.FieldSymbol)
+
+                    If memberSymbol Is Nothing Then
+                        Continue For
+                    End If
+
+                    Dim requiredMember As Symbol = Nothing
+                    If Not requiredMembersBuilder.TryGetValue(memberSymbol.Name, requiredMember) Then
+                        Continue For
+                    End If
+
+                    If Not memberSymbol.Equals(requiredMember, TypeCompareKind.ConsiderEverything) Then
+                        Continue For
+                    End If
+
+                    requiredMembersBuilder.Remove(memberSymbol.Name)
+                Next
+            End If
+
+            For Each kvp In requiredMembersBuilder
+                diagnostics.Add(ERRID.ERR_RequiredMemberMustBeSet, creationSyntax.Location, kvp.Value)
+            Next
+        End Sub
+
         Private Function BindNoPiaObjectCreationExpression(
             node As SyntaxNode,
             [interface] As TypeSymbol,

src/Compilers/VisualBasic/Portable/Binding/Binder_XmlLiterals.vb

@@ -1713,6 +1713,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
 
+        Public Overrides ReadOnly Property IsRequired As Boolean
+            Get
+                Return False
+            End Get
+        End Property
+
         Private NotInheritable Class ReducedExtensionAccessorSymbol
             Inherits MethodSymbol
 
@@ -1987,6 +1993,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Friend Overrides Function CalculateLocalSyntaxOffset(localPosition As Integer, localTree As SyntaxTree) As Integer
                 Throw ExceptionUtilities.Unreachable
             End Function
+
+            Friend Overrides ReadOnly Property HasSetsRequiredMembers As Boolean
+                Get
+                    Return False
+                End Get
+            End Property
         End Class
 
         Private NotInheritable Class ReducedAccessorParameterSymbol

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

@@ -1355,6 +1355,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                      ERRID.ERR_StdInOptionProvidedButConsoleInputIsNotRedirected,
                      ERRID.ERR_UnsupportedCompilerFeature,
                      ERRID.ERR_DoNotUseCompilerFeatureRequired,
+                     ERRID.ERR_RequiredMemberMustBeSet,
+                     ERRID.ERR_CannotInheritFromTypeWithRequiredMembers,
+                     ERRID.ERR_RequiredMembersInvalid,
+                     ERRID.ERR_NewConstraintCannotHaveRequiredMembers,
                      ERRID.ERR_NextAvailable,
                      ERRID.WRN_UseOfObsoleteSymbol2,
                      ERRID.WRN_InvalidOverrideDueToTupleNames2,

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

@@ -1767,7 +1767,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         ERR_UnsupportedCompilerFeature = 37319
         ERR_DoNotUseCompilerFeatureRequired = 37320
 
-        ERR_NextAvailable = 37321
+        ERR_RequiredMemberMustBeSet = 37321
+        ERR_CannotInheritFromTypeWithRequiredMembers = 37322
+        ERR_RequiredMembersInvalid = 37323
+        ERR_NewConstraintCannotHaveRequiredMembers = 37324
+
+        ERR_NextAvailable = 37325
 
         '// WARNINGS BEGIN HERE
         WRN_UseOfObsoleteSymbol2 = 40000

src/Compilers/VisualBasic/Portable/Lowering/StateMachineRewriter/SynthesizedContainer.vb

@@ -321,5 +321,17 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
         Friend NotOverridable Overrides Function GetSynthesizedWithEventsOverrides() As IEnumerable(Of PropertySymbol)
             Return SpecializedCollections.EmptyEnumerable(Of PropertySymbol)()
         End Function
+
+        Friend NotOverridable Overrides ReadOnly Property AllRequiredMembers As ImmutableSegmentedDictionary(Of String, Symbol)
+            Get
+                Return ImmutableSegmentedDictionary(Of String, Symbol).Empty
+            End Get
+        End Property
+
+        Friend NotOverridable Overrides ReadOnly Property HasRequiredMembersError As Boolean
+            Get
+                Return False
+            End Get
+        End Property
     End Class
 End Namespace

src/Compilers/VisualBasic/Portable/Symbols/AnonymousTypes/PublicSymbols/AnonymousTypeOrDelegatePublicSymbol.vb

@@ -5,6 +5,7 @@
 Imports System.Collections.Immutable
 Imports System.Runtime.InteropServices
 Imports System.Threading
+Imports Microsoft.CodeAnalysis.Collections
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
     Partial Friend NotInheritable Class AnonymousTypeManager
@@ -328,7 +329,18 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
             Public NotOverridable Overrides Function GetHashCode() As Integer
                 Return Hash.Combine(Me.TypeDescriptor.GetHashCode(), TypeKind)
             End Function
-        End Class
 
+            Friend NotOverridable Overrides ReadOnly Property AllRequiredMembers As ImmutableSegmentedDictionary(Of String, Symbol)
+                Get
+                    Return ImmutableSegmentedDictionary(Of String, Symbol).Empty
+                End Get
+            End Property
+
+            Friend NotOverridable Overrides ReadOnly Property HasRequiredMembersError As Boolean
+                Get
+                    Return False
+                End Get
+            End Property
+        End Class
     End Class
 End Namespace

src/Compilers/VisualBasic/Portable/Symbols/AnonymousTypes/SynthesizedSymbols/AnonymousTypeOrDelegateTemplateSymbol.vb

@@ -7,6 +7,7 @@ Imports System.Runtime.InteropServices
 Imports System.Threading
 Imports Microsoft.Cci
 Imports Microsoft.CodeAnalysis
+Imports Microsoft.CodeAnalysis.Collections
 Imports Microsoft.CodeAnalysis.Emit
 Imports Microsoft.CodeAnalysis.Symbols
 
@@ -380,6 +381,18 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
             Friend NotOverridable Overrides Function GetSynthesizedWithEventsOverrides() As IEnumerable(Of PropertySymbol)
                 Return SpecializedCollections.EmptyEnumerable(Of PropertySymbol)()
             End Function
+
+            Friend NotOverridable Overrides ReadOnly Property AllRequiredMembers As ImmutableSegmentedDictionary(Of String, Symbol)
+                Get
+                    Return ImmutableSegmentedDictionary(Of String, Symbol).Empty
+                End Get
+            End Property
+
+            Friend NotOverridable Overrides ReadOnly Property HasRequiredMembersError As Boolean
+                Get
+                    Return False
+                End Get
+            End Property
         End Class
 
     End Class

src/Compilers/VisualBasic/Portable/Symbols/AnonymousTypes/SynthesizedSymbols/AnonymousType_PropertySymbol.vb

@@ -217,6 +217,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                     Return False
                 End Get
             End Property
+
+            Public Overrides ReadOnly Property IsRequired As Boolean
+                Get
+                    Return False
+                End Get
+            End Property
         End Class
 
     End Class