Reference Assembly Annotator

IL weaver for adding nullability annotations to .NET Framework, .NET Standard, and .NET Core reference assemblies.

This is the continuation of TunnelVisionLabs.ReferenceAssemblyAnnotator, published as ICSharpCode.ReferenceAssemblyAnnotator. To migrate, replace the package ID; the MSBuild properties and items are unchanged.

Requirements

• Build: .NET SDK 8 or newer, or Visual Studio 2022 version 17.8 or newer.

Usage

Assemblies included by default

• .NET Framework targets
  • mscorlib
  • System
  • System.Core
  • System.Data
  • System.Drawing
  • System.IO.Compression.FileSystem
  • System.Numerics
  • System.Runtime.Serialization
  • System.Xml
  • System.Xml.Linq
• .NET Standard targets
  • All assemblies which are defined by the .NET Standard
• .NET Core targets before 3.0
  • All reference assemblies defined by .NET Core

.NET Core 3.0 and newer are not annotated: their reference assemblies already carry nullable annotations. Don't add the Microsoft.NETCore.App.Ref PackageDownload for those target frameworks. The SDK may download that package itself, and a second download fails restore with NU1505. When multi-targeting, condition it, for example:

<!-- <TargetFrameworks>netstandard2.0;net10.0</TargetFrameworks> -->
<PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" Condition="'$(TargetFramework)' != 'net10.0'" />

Example configuration

<PropertyGroup>
  <!-- By default, the nullable attributes from dotnet/coreclr are included as source code with 'internal'
       accessibility. Uncomment to suppress this if the attributes are included from another source and/or
       are not needed. -->
  
  <!-- <GenerateNullableAttributes>false</GenerateNullableAttributes> -->
</PropertyGroup>

<ItemGroup>
  <PackageReference Include="ICSharpCode.ReferenceAssemblyAnnotator" Version="2.0.0-preview.*" PrivateAssets="all" />

  <!-- Specifies the version of Microsoft.NETCore.App.Ref to obtain nullability information from. -->
  <PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" />
</ItemGroup>

Minimal:

<ItemGroup>
  <PackageReference Include="ICSharpCode.ReferenceAssemblyAnnotator" Version="2.0.0-preview.*" PrivateAssets="all" />
  <PackageDownload Include="Microsoft.NETCore.App.Ref" Version="[10.0.0]" />
</ItemGroup>

Configuration reference

• MSBuild properties
  • <AnnotatedReferenceAssemblyVersion>: Specifies the version of Microsoft.NETCore.App.Ref to obtain nullability information from. This is required if there are multiple PackageDownload versions of Microsoft.NETCore.App.Ref.
  • <GenerateNullableAttributes>: Set to True to include definitions of nullability attributes in the build; otherwise, False to exclude the definitions. The default value is True.
• MSBuild items
  • <UnannotatedReferenceAssembly>: Specifies reference assemblies to annotate. This is only required for assemblies that are not automatically annotated by this package.

Releases

• Binaries (NuGet)
• Release Notes
• License