NullReferenceException in ConvertComImportToGeneratedComInterfaceAnalyzer

[meziantou]

Description

Visual Studio reports AD0001 Analyzer 'Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'.

Note that dotnet build doesn't report any warning.

Reproduction Steps

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>
</Project>

using System.Runtime.InteropServices;

namespace ClassLibrary1;

[ComImport()]
[Guid("42f85136-db7e-439c-85f1-e4075d135fc8")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
internal interface IFileDialog
{
    [PreserveSig]
    int Show([In] nint parent);
}

[ComImport()]
[Guid("d57c7288-d4ad-4768-be02-9d969532d960")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
internal interface IFileOpenDialog : IFileDialog
{
    [PreserveSig]
    new int Show([In] nint parent);
}

[ComImport]
[Guid("d57c7288-d4ad-4768-be02-9d969532d960")]
[CoClass(typeof(FileOpenDialogRCW))]
internal interface NativeFileOpenDialog : IFileOpenDialog
{
}

[ComImport]
[ClassInterface(ClassInterfaceType.None)]
[Guid("DC1C5A9C-E88A-4dde-A5A1-60F82A20AEF7")]
internal class FileOpenDialogRCW
{
}

Expected behavior

No warning in Visual Studio

Actual behavior

Warning	AD0001	Analyzer 'Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'.
Exception occurred with following context:
Compilation: ClassLibrary1
ISymbol: NativeFileOpenDialog (NamedType)

System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer.<>c__DisplayClass3_0.<Initialize>b__2(SymbolAnalysisContext context)
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.ExecuteAndCatchIfThrows_NoLock[TArg](DiagnosticAnalyzer analyzer, Action`1 analyze, TArg argument, Nullable`1 info, CancellationToken cancellationToken)

Regression?

No response

Known Workarounds

No response

Configuration

Visual Studio version: 17.9.0 Preview 1.0

dotnet --info

.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.71b9f198

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22635
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\8.0.100\

.NET workloads installed:
 Workload version: 8.0.100-manifests.71b9f198
There are no installed workloads to display.

Host:
  Version:      8.0.0
  Architecture: x64
  Commit:       5535e31a71

.NET SDKs installed:
  8.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Other information

No response

[jtschuster]

I can't reproduce this error with the same setup on VS Community 17.9.0 Preview 1. Did you hit this while editing code, or when running a build in VS?

[meziantou]

• It only repro in VS. The warning appears a few seconds after pasting the code from the initial message (no need to run a build). You need to select "IntelliSense" or "Build + IntelliSense" in the Error window.
• The CLI doesn't report any error

Full VS version: Microsoft Visual Studio Enterprise 2022 (64-bit) - Preview, Version 17.9.0 Preview 1.0

Tagging subscribers to this area: @dotnet/interop-contrib
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

Visual Studio reports AD0001 Analyzer 'Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'.

Note that dotnet build doesn't report any warning.

Reproduction Steps

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>
</Project>

using System.Runtime.InteropServices;

namespace ClassLibrary1;

[ComImport()]
[Guid("42f85136-db7e-439c-85f1-e4075d135fc8")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
internal interface IFileDialog
{
    [PreserveSig]
    int Show([In] nint parent);
}

[ComImport()]
[Guid("d57c7288-d4ad-4768-be02-9d969532d960")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
internal interface IFileOpenDialog : IFileDialog
{
    [PreserveSig]
    new int Show([In] nint parent);
}

[ComImport]
[Guid("d57c7288-d4ad-4768-be02-9d969532d960")]
[CoClass(typeof(FileOpenDialogRCW))]
internal interface NativeFileOpenDialog : IFileOpenDialog
{
}

[ComImport]
[ClassInterface(ClassInterfaceType.None)]
[Guid("DC1C5A9C-E88A-4dde-A5A1-60F82A20AEF7")]
internal class FileOpenDialogRCW
{
}

Expected behavior

No warning in Visual Studio

Actual behavior

Warning	AD0001	Analyzer 'Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'.
Exception occurred with following context:
Compilation: ClassLibrary1
ISymbol: NativeFileOpenDialog (NamedType)

System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.Interop.Analyzers.ConvertComImportToGeneratedComInterfaceAnalyzer.<>c__DisplayClass3_0.<Initialize>b__2(SymbolAnalysisContext context)
   at Microsoft.CodeAnalysis.Diagnostics.AnalyzerExecutor.ExecuteAndCatchIfThrows_NoLock[TArg](DiagnosticAnalyzer analyzer, Action`1 analyze, TArg argument, Nullable`1 info, CancellationToken cancellationToken)

Regression?

No response

Known Workarounds

No response

Configuration

Visual Studio version: 17.9.0 Preview 1.0

dotnet --info

.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.71b9f198

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22635
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\8.0.100\

.NET workloads installed:
 Workload version: 8.0.100-manifests.71b9f198
There are no installed workloads to display.

Host:
  Version:      8.0.0
  Architecture: x64
  Commit:       5535e31a71

.NET SDKs installed:
  8.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Other information

No response

Author:	meziantou
Assignees:	-
Labels:	area-System.Runtime.InteropServices, code-analyzer
Milestone:	-

[powercode]

Same in Preview 2.0 Professional.