Fix null ref exception in Symbol.CanBeReferencedByName for VB (#71253)

Fixes #71115.
dotnet · Dec 14, 2023 · 3560634 · 3560634
1 parent 01173c5
commit 3560634
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Showing 3 changed files with 188 additions and 2 deletions.
diff --git a/src/Compilers/VisualBasic/Portable/Analysis/FlowAnalysis/DataFlowPass.vb b/src/Compilers/VisualBasic/Portable/Analysis/FlowAnalysis/DataFlowPass.vb
@@ -1022,6 +1022,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
  Case BoundKind.Local
  Dim local As LocalSymbol = DirectCast(node, BoundLocal).LocalSymbol
+
+ If local.IsCompilerGenerated AndAlso Not Me.ProcessCompilerGeneratedLocals Then
+ ' For consistency with Assign behavior, which does not process compiler generated temporary locals.
+ Return True
+ End If
+
  If local.DeclarationKind <> LocalDeclarationKind.AmbiguousLocals Then
  unassignedSlot = VariableSlot(local)
 

diff --git a/src/Compilers/VisualBasic/Portable/Symbols/Symbol.vb b/src/Compilers/VisualBasic/Portable/Symbols/Symbol.vb
@@ -589,8 +589,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
  Public ReadOnly Property CanBeReferencedByName As Boolean
  Get
  Select Case Me.Kind
- Case SymbolKind.Local,
- SymbolKind.Label,
+ Case SymbolKind.Local
+ Return If(Me.Name?.Length, 0) > 0
+
+ Case SymbolKind.Label,
  SymbolKind.Alias
  ' Can't be imported, but might have syntax errors in which case we use an empty name:
  Return Me.Name.Length > 0

diff --git a/src/Compilers/VisualBasic/Test/Emit/CodeGen/CodeGenRefReturnTests.vb b/src/Compilers/VisualBasic/Test/Emit/CodeGen/CodeGenRefReturnTests.vb
@@ -3593,6 +3593,184 @@ End Module",
  verifier.VerifyDiagnostics()
  End Sub
 
+ <Fact>
+ <WorkItem("https://github.com/dotnet/roslyn/issues/71115")>
+ Public Sub With_RegionAnalysisRefIndexer()
+ Dim comp1 = CreateCSharpCompilation(
+"public class C<T>
+{
+ private T _p;
+ public ref T this[int i]
+ {
+ get { return ref _p; }
+ }
+}")
+ comp1.VerifyDiagnostics()
+ Dim comp2 = CreateVisualBasicCompilation(
+ Nothing,
+"
+Public Class LocalDeclConversionError
+ Private Structure SomeStruct
+ Dim SomeField As Integer
+ Dim Text As String
+ End Structure
+
+ Dim lst As New C(Of SomeStruct)
+
+ Sub S()
+ Dim s As String
+
+ With lst(0)
+ .SomeField = 5
+ s = .Text
+ End With
+ End Sub
+End Class
+",
+ referencedCompilations:={comp1},
+ compilationOptions:=TestOptions.DebugDll)
+
+ comp2.AssertTheseEmitDiagnostics()
+
+ Dim tree = comp2.SyntaxTrees(0)
+ Dim model = comp2.GetSemanticModel(tree)
+ Dim syntax = tree.GetRoot().DescendantNodes().OfType(Of Syntax.MethodBlockBaseSyntax).Single()
+
+ Dim methodFlow = model.AnalyzeDataFlow(syntax.Statements.First(), syntax.Statements.Last())
+ Assert.True(methodFlow.Succeeded)
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.ReadInside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.AlwaysAssigned))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.Captured))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DataFlowsIn))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.DataFlowsOut))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnEntry))
+ Assert.Equal("[Me], [s]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnExit))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.ReadOutside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.VariablesDeclared))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.WrittenInside))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.WrittenOutside))
+ End Sub
+
+ <Fact>
+ <WorkItem("https://github.com/dotnet/roslyn/issues/71115")>
+ Public Sub With_RegionAnalysisRefProperty()
+ Dim comp1 = CreateCSharpCompilation(
+"public class C<T>
+{
+ private T _p;
+ public ref T P
+ {
+ get { return ref _p; }
+ }
+}")
+ comp1.VerifyDiagnostics()
+ Dim comp2 = CreateVisualBasicCompilation(
+ Nothing,
+"
+Public Class LocalDeclConversionError
+ Private Structure SomeStruct
+ Dim SomeField As Integer
+ Dim Text As String
+ End Structure
+
+ Dim lst As New C(Of SomeStruct)
+
+ Sub S()
+ Dim s As String
+
+ With lst.P
+ .SomeField = 5
+ s = .Text
+ End With
+ End Sub
+End Class
+",
+ referencedCompilations:={comp1},
+ compilationOptions:=TestOptions.DebugDll)
+
+ comp2.AssertTheseEmitDiagnostics()
+
+ Dim tree = comp2.SyntaxTrees(0)
+ Dim model = comp2.GetSemanticModel(tree)
+ Dim syntax = tree.GetRoot().DescendantNodes().OfType(Of Syntax.MethodBlockBaseSyntax).Single()
+
+ Dim methodFlow = model.AnalyzeDataFlow(syntax.Statements.First(), syntax.Statements.Last())
+ Assert.True(methodFlow.Succeeded)
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.ReadInside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.AlwaysAssigned))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.Captured))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DataFlowsIn))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.DataFlowsOut))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnEntry))
+ Assert.Equal("[Me], [s]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnExit))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.ReadOutside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.VariablesDeclared))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.WrittenInside))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.WrittenOutside))
+ End Sub
+
+ <Fact>
+ <WorkItem("https://github.com/dotnet/roslyn/issues/71115")>
+ Public Sub With_RegionAnalysisRefMethod()
+ Dim comp1 = CreateCSharpCompilation(
+"public class C<T>
+{
+ private T _p;
+ public ref T GetP()
+ {
+ return ref _p;
+ }
+}")
+ comp1.VerifyDiagnostics()
+ Dim comp2 = CreateVisualBasicCompilation(
+ Nothing,
+"
+Public Class LocalDeclConversionError
+ Private Structure SomeStruct
+ Dim SomeField As Integer
+ Dim Text As String
+ End Structure
+
+ Dim lst As New C(Of SomeStruct)
+
+ Sub S()
+ Dim s As String
+
+ With lst.GetP()
+ .SomeField = 5
+ s = .Text
+ End With
+ End Sub
+End Class
+",
+ referencedCompilations:={comp1},
+ compilationOptions:=TestOptions.DebugDll)
+
+ comp2.AssertTheseEmitDiagnostics()
+
+ Dim tree = comp2.SyntaxTrees(0)
+ Dim model = comp2.GetSemanticModel(tree)
+ Dim syntax = tree.GetRoot().DescendantNodes().OfType(Of Syntax.MethodBlockBaseSyntax).Single()
+
+ Dim methodFlow = model.AnalyzeDataFlow(syntax.Statements.First(), syntax.Statements.Last())
+ Assert.True(methodFlow.Succeeded)
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.ReadInside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.AlwaysAssigned))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.Captured))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DataFlowsIn))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.DataFlowsOut))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnEntry))
+ Assert.Equal("[Me], [s]", GetSymbolNamesJoined(methodFlow.DefinitelyAssignedOnExit))
+ Assert.Equal(Nothing, GetSymbolNamesJoined(methodFlow.ReadOutside))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.VariablesDeclared))
+ Assert.Equal("[s]", GetSymbolNamesJoined(methodFlow.WrittenInside))
+ Assert.Equal("[Me]", GetSymbolNamesJoined(methodFlow.WrittenOutside))
+ End Sub
+
+ Protected Shared Function GetSymbolNamesJoined(Of T As ISymbol)(symbols As IEnumerable(Of T)) As String
+ Return If(Not symbols.IsEmpty(), String.Join(", ", symbols.Select(Function(symbol) "[" + symbol.Name + "]")), Nothing)
+ End Function
+
  End Class
 
 End Namespace