icsharpcode · TymurGubayev · Dec 8, 2023 · Dec 8, 2023 · Dec 8, 2023 · Dec 8, 2023
diff --git a/CodeConverter/CSharp/CommonConversions.cs b/CodeConverter/CSharp/CommonConversions.cs
@@ -598,7 +598,7 @@ public CSSyntax.IdentifierNameSyntax GetRetVariableNameOrNull(VBSyntax.MethodBlo
             var flow = SemanticModel.AnalyzeDataFlow(node.Statements.First(), node.Statements.Last());
 
             if (flow.Succeeded) {
-                assignsToMethodNameVariable = flow.ReadInside.Any(equalsMethodName) || flow.WrittenInside.Any(equalsMethodName);
+                assignsToMethodNameVariable = flow.ReadInsideSafe().Any(equalsMethodName) || flow.WrittenInside.Any(equalsMethodName);
             }
         }
 

diff --git a/CodeConverter/CSharp/DataFlowAnalysisExtensions.cs b/CodeConverter/CSharp/DataFlowAnalysisExtensions.cs
@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace ICSharpCode.CodeConverter.CSharp;
+internal static class DataFlowAnalysisExtensions
+{
+    /// <summary>
+    /// Accesses the <see cref="DataFlowAnalysis.ReadInside" /> second time in case of exception.
+    /// This is a workaround for a bug present in Roslyn up to version 4.8.0
+    /// (https://github.com/dotnet/roslyn/issues/71115)
+    /// </summary>
+    public static System.Collections.Immutable.ImmutableArray<ISymbol> ReadInsideSafe(this DataFlowAnalysis dataFlow)
+    {
+        try {
+            return dataFlow.ReadInside;
+        } catch {
+            return dataFlow.ReadInside;
+        }
+    }
+}
diff --git a/CodeConverter/CSharp/DefiniteAssignmentAnalyzer.cs b/CodeConverter/CSharp/DefiniteAssignmentAnalyzer.cs
@@ -5,7 +5,7 @@ internal static class DefiniteAssignmentAnalyzer
 
     public static bool IsDefinitelyAssignedBeforeRead(ISymbol localSymbol, DataFlowAnalysis methodFlow)
     {
-        if (!methodFlow.ReadInside.Contains(localSymbol)) return true;
+        if (!methodFlow.ReadInsideSafe().Contains(localSymbol)) return true;
         var unassignedVariables = methodFlow.GetVbUnassignedVariables();
         return unassignedVariables != null && !unassignedVariables.Contains(localSymbol, SymbolEqualityComparer.IncludeNullability);
     }

diff --git a/...terization/SourceFiles/CSharpDllWithRefReturnIndexer/CSharpDllWithRefReturnIndexer.csproj b/...terization/SourceFiles/CSharpDllWithRefReturnIndexer/CSharpDllWithRefReturnIndexer.csproj
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{E6A02631-FF88-4FDE-A356-1EC4CA397445}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>CSharpDllWithRefReturnIndexer</RootNamespace>
+    <AssemblyName>CSharpDllWithRefReturnIndexer</AssemblyName>
+    <TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="SpecialListWithRefReturnIndexer.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>
diff --git a/...FileCharacterization/SourceFiles/CSharpDllWithRefReturnIndexer/Properties/AssemblyInfo.cs b/...FileCharacterization/SourceFiles/CSharpDllWithRefReturnIndexer/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("CSharpDllWithRefReturnIndexer")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("CSharpDllWithRefReturnIndexer")]
+[assembly: AssemblyCopyright("Copyright ©  2023")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("e6a02631-ff88-4fde-a356-1ec4ca397445")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/...acterization/SourceFiles/CSharpDllWithRefReturnIndexer/SpecialListWithRefReturnIndexer.cs b/...acterization/SourceFiles/CSharpDllWithRefReturnIndexer/SpecialListWithRefReturnIndexer.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CSharpDllWithRefReturnIndexer
+{
+    public class SpecialListWithRefReturnIndexer<T>
+    {
+        private T dummy;
+        public ref T this[int i] {
+            get {
+                return ref dummy;
+            }
+        }
+    }
+}
diff --git a/Tests/TestData/MultiFileCharacterization/SourceFiles/CharacterizationTestSolution.sln b/Tests/TestData/MultiFileCharacterization/SourceFiles/CharacterizationTestSolution.sln
@@ -26,6 +26,10 @@ Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "Prefix.VbLibrary", "Prefix.
 EndProject
 Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "VisualBasicConsoleApp", "ConsoleApp1\VisualBasicConsoleApp.vbproj", "{C69D27C1-FF4E-43CB-BB0F-9BF811BF0F81}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CSharpDllWithRefReturnIndexer", "CSharpDllWithRefReturnIndexer\CSharpDllWithRefReturnIndexer.csproj", "{E6A02631-FF88-4FDE-A356-1EC4CA397445}"
+EndProject
+Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "VbNetUsingCSharpRefReturnIndexer", "VbNetUsingCSharpRefReturnIndexer\VbNetUsingCSharpRefReturnIndexer.vbproj", "{FAA9F1FC-C0BC-41DC-8CC7-D8D1DCBB6FEA}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -68,6 +72,14 @@ Global
 		{C69D27C1-FF4E-43CB-BB0F-9BF811BF0F81}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C69D27C1-FF4E-43CB-BB0F-9BF811BF0F81}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C69D27C1-FF4E-43CB-BB0F-9BF811BF0F81}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E6A02631-FF88-4FDE-A356-1EC4CA397445}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E6A02631-FF88-4FDE-A356-1EC4CA397445}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E6A02631-FF88-4FDE-A356-1EC4CA397445}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E6A02631-FF88-4FDE-A356-1EC4CA397445}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FAA9F1FC-C0BC-41DC-8CC7-D8D1DCBB6FEA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FAA9F1FC-C0BC-41DC-8CC7-D8D1DCBB6FEA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FAA9F1FC-C0BC-41DC-8CC7-D8D1DCBB6FEA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FAA9F1FC-C0BC-41DC-8CC7-D8D1DCBB6FEA}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

diff --git a/...TestData/MultiFileCharacterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/Class1.vb b/...TestData/MultiFileCharacterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/Class1.vb
@@ -0,0 +1,18 @@
+Public Class Class1
+    Private Structure SomeStruct
+        Dim SomeField As Integer
+        Dim Text As String
+    End Structure
+
+    Dim lst As New CSharpDllWithRefReturnIndexer.SpecialListWithRefReturnIndexer(Of SomeStruct)
+
+    Sub S()
+        Dim i As Integer
+        Dim s As String
+
+        With lst(i)
+            .SomeField = 5
+            s = .Text
+        End With
+    End Sub
+End Class
diff --git a/...erization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Application.Designer.vb b/...erization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Application.Designer.vb
diff --git a/...haracterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Application.myapp b/...haracterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Application.myapp
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<MyApplicationData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
+  <MySubMain>false</MySubMain>
+  <SingleInstance>false</SingleInstance>
+  <ShutdownMode>0</ShutdownMode>
+  <EnableVisualStyles>true</EnableVisualStyles>
+  <AuthenticationMode>0</AuthenticationMode>
+  <ApplicationType>1</ApplicationType>
+  <SaveMySettingsOnExit>true</SaveMySettingsOnExit>
+</MyApplicationData>
diff --git a/...eCharacterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/AssemblyInfo.vb b/...eCharacterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/AssemblyInfo.vb
@@ -0,0 +1,35 @@
+Imports System
+Imports System.Reflection
+Imports System.Runtime.InteropServices
+
+' General Information about an assembly is controlled through the following
+' set of attributes. Change these attribute values to modify the information
+' associated with an assembly.
+
+' Review the values of the assembly attributes
+
+<Assembly: AssemblyTitle("VbNetUsingCSharpRefReturnIndexer")>
+<Assembly: AssemblyDescription("")>
+<Assembly: AssemblyCompany("")>
+<Assembly: AssemblyProduct("VbNetUsingCSharpRefReturnIndexer")>
+<Assembly: AssemblyCopyright("Copyright ©  2023")>
+<Assembly: AssemblyTrademark("")>
+
+<Assembly: ComVisible(False)>
+
+'The following GUID is for the ID of the typelib if this project is exposed to COM
+<Assembly: Guid("be11cb47-e713-43a7-82df-453d58c71116")>
+
+' Version information for an assembly consists of the following four values:
+'
+'      Major Version
+'      Minor Version
+'      Build Number
+'      Revision
+'
+' You can specify all the values or you can default the Build and Revision Numbers
+' by using the '*' as shown below:
+' <Assembly: AssemblyVersion("1.0.*")>
+
+<Assembly: AssemblyVersion("1.0.0.0")>
+<Assembly: AssemblyFileVersion("1.0.0.0")>
diff --git a/...cterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Resources.Designer.vb b/...cterization/SourceFiles/VbNetUsingCSharpRefReturnIndexer/My Project/Resources.Designer.vb