Merge pull request #19885 from 333fred/fix-syntax-nothing

Fix VB IUsingStatement.Declaration to not have null syntax.

src/Compilers/VisualBasic/Portable/BoundTree/Statement.vb

@@ -3,6 +3,7 @@
 Imports System.Collections.Immutable
 Imports Microsoft.CodeAnalysis.Semantics
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
+Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic
 
@@ -176,7 +177,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Private ReadOnly _syntax As SyntaxNode
 
             Public Sub New(boundCaseBlock As BoundCaseBlock)
-                ' `CaseElseClauseSyntax` is bound to `BoundCaseStatement` with an empty list of case clauses, 
+                ' `CaseElseClauseSyntax` is bound to `BoundCaseStatement` with an empty list of case clauses,
                 ' so we explicitly create an IOperation node for Case-Else clause to differentiate it from Case clause.
                 Dim caseStatement = boundCaseBlock.CaseStatement
                 If caseStatement.CaseClauses.IsEmpty AndAlso caseStatement.Syntax.Kind() = SyntaxKind.CaseElseStatement Then
@@ -1460,7 +1461,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 Return s_variablesMappings.GetValue(
                     Me,
                     Function(BoundUsing)
-                        Return New Variables(BoundUsing.ResourceList.As(Of IVariableDeclaration))
+                        If BoundUsing.ResourceList.IsDefault Then
+                            Return Nothing
+                        End If
+                        Dim usingStatementSyntax = DirectCast(Syntax, UsingBlockSyntax).UsingStatement
+                        Return New Variables(BoundUsing.ResourceList.As(Of IVariableDeclaration), usingStatementSyntax)
                     End Function)
             End Get
         End Property
@@ -1487,9 +1492,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Implements IVariableDeclarationStatement
 
             Private ReadOnly _variables As ImmutableArray(Of IVariableDeclaration)
+            Private ReadOnly _syntax As SyntaxNode
 
-            Public Sub New(variables As ImmutableArray(Of IVariableDeclaration))
+            Public Sub New(variables As ImmutableArray(Of IVariableDeclaration), syntax As UsingStatementSyntax)
                 _variables = variables
+                _syntax = syntax
             End Sub
 
             Public Sub Accept(visitor As OperationVisitor) Implements IOperation.Accept
@@ -1514,7 +1521,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
             Public ReadOnly Property Syntax As SyntaxNode Implements IOperation.Syntax
                 Get
-                    Return Nothing
+                    Return _syntax
                 End Get
             End Property
 

src/Compilers/VisualBasic/Test/Semantic/BasicCompilerSemanticTest.vbproj

@@ -128,6 +128,7 @@
     <Compile Include="FlowAnalysis\RegionAnalysisTestsWithStaticLocals.vb" />
     <Compile Include="FlowAnalysis\StructureAnalysisTests.vb" />
     <Compile Include="FlowAnalysis\TryLockUsingStatementTests.vb" />
+    <Compile Include="IOperation\IOperationTests_IUsingStatement.vb" />
     <Compile Include="IOperation\IOperationTests_IVariableDeclaration.vb" />
     <Compile Include="Resource.Designer.vb">
       <AutoGen>True</AutoGen>

src/Compilers/VisualBasic/Test/Semantic/IOperation/IOperationTests_IUsingStatement.vb

+Imports Microsoft.CodeAnalysis.Semantics
+Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
+Imports Roslyn.Test.Utilities
+
+Namespace Microsoft.CodeAnalysis.VisualBasic.UnitTests.Semantics
+    Partial Public Class IOperationTests
+        Inherits SemanticModelTestBase
+
+        <Fact>
+        <WorkItem(19819, "https://github.com/dotnet/roslyn/issues/19819")>
+        Public Sub UsingDeclarationSyntaxNotNull()
+            Dim source = <compilation>
+                             <file name="c.vb">
+                                 <![CDATA[
+Imports System
+Module Module1
+    Class C1
+        Implements IDisposable
+        Public Sub Dispose() Implements IDisposable.Dispose
+            Throw New NotImplementedException()
+        End Sub
+    End Class
+    Sub S1()
+        Using D1 as New C1()
+        End Using
+    End Sub
+End Module
+]]>
+                             </file>
+                         </compilation>
+
+            Dim comp = CreateCompilationWithMscorlibAndVBRuntime(source, parseOptions:=TestOptions.RegularWithIOperationFeature)
+            CompilationUtils.AssertNoDiagnostics(comp)
+
+            Dim tree = comp.SyntaxTrees.Single()
+            Dim node = tree.GetRoot().DescendantNodes().OfType(Of UsingBlockSyntax).Single()
+            Dim op = DirectCast(comp.GetSemanticModel(tree).GetOperationInternal(node), IUsingStatement)
+
+            Assert.NotNull(op.Declaration.Syntax)
+            Assert.Same(node.UsingStatement, op.Declaration.Syntax)
+        End Sub
+
+        <Fact>
+        <WorkItem(19887, "https://github.com/dotnet/roslyn/issues/19887")>
+        Public Sub UsingDeclarationIncompleteUsingNullDeclaration()
+            Dim source = <compilation>
+                             <file name="c.vb">
+                                 <![CDATA[
+Imports System
+Module Module1
+    Class C1
+        Implements IDisposable
+        Public Sub Dispose() Implements IDisposable.Dispose
+            Throw New NotImplementedException()
+        End Sub
+    End Class
+    Sub S1()
+        Using
+        End Using
+    End Sub
+End Module
+]]>
+                             </file>
+                         </compilation>
+
+            Dim comp = CreateCompilationWithMscorlibAndVBRuntime(source, parseOptions:=TestOptions.RegularWithIOperationFeature)
+            CompilationUtils.AssertTheseDiagnostics(comp,
+                                        <expected>
+BC30201: Expression expected.
+        Using
+             ~
+                                        </expected>)
+
+            Dim tree = comp.SyntaxTrees.Single()
+            Dim node = tree.GetRoot().DescendantNodes().OfType(Of UsingBlockSyntax).Single()
+            Dim op = DirectCast(comp.GetSemanticModel(tree).GetOperationInternal(node), IUsingStatement)
+
+            Assert.Null(op.Declaration)
+        End Sub
+
+        <Fact>
+        <WorkItem(19887, "https://github.com/dotnet/roslyn/issues/19887")>
+        Public Sub UsingDeclarationExistingVariableNullDeclaration()
+            Dim source = <compilation>
+                             <file name="c.vb">
+                                 <![CDATA[
+Imports System
+Module Module1
+    Class C1
+        Implements IDisposable
+        Public Sub Dispose() Implements IDisposable.Dispose
+            Throw New NotImplementedException()
+        End Sub
+    End Class
+    Sub S1()
+        Dim x = New C1()
+        Using x
+        End Using
+    End Sub
+End Module
+]]>
+                             </file>
+                         </compilation>
+
+            Dim comp = CreateCompilationWithMscorlibAndVBRuntime(source, parseOptions:=TestOptions.RegularWithIOperationFeature)
+            CompilationUtils.AssertNoDiagnostics(comp)
+
+            Dim tree = comp.SyntaxTrees.Single()
+            Dim node = tree.GetRoot().DescendantNodes().OfType(Of UsingBlockSyntax).Single()
+            Dim op = DirectCast(comp.GetSemanticModel(tree).GetOperationInternal(node), IUsingStatement)
+
+            Assert.Null(op.Declaration)
+        End Sub
+    End Class
+End Namespace