GenericSymbolReferenceTree

C# incremental generator utility to produce a tree of closed generic symbols used in your project's compilation, each paired with a syntax node.

How to use this project

This project is designed to be used with a C# incremental generator to discover closed generic symbols that are referenced in your project's compilation. Accordingly, the first step in using this project is to add the necessary references to your csproj file.

The pre-built binaries of this project are available as a NuGet Package. Your csproj file may look like this:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Library</OutputType>
    <TargetFramework>netstandard2.0</TargetFramework>
    <Nullable>enable</Nullable>
    <LangVersion>preview</LangVersion>
    <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
    <PublishAot>false</PublishAot>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
    <PackageReference Include="Monkeymoto.GeneratorUtils.GenericSymbolReferenceTree" Version="2.0.0">
      <PrivateAssets>all</PrivateAssets>
      <GeneratePathProperty>true</GeneratePathProperty>
    </PackageReference>
  </ItemGroup>

  <PropertyGroup>
    <GetTargetPathDependsOn>$(GetTargetPathDependsOn);GetDependencyTargetPaths</GetTargetPathDependsOn>
  </PropertyGroup>

  <Target Name="GetDependencyTargetPaths">
    <ItemGroup>
      <TargetPathWithTargetPlatformMoniker Include="$(PKGMonkeymoto_GeneratorUtils_GenericSymbolReferenceTree)\lib\netstandard2.0\Monkeymoto.GeneratorUtils.GenericSymbolReferenceTree.dll" IncludeRuntimeDependency="false" />
    </ItemGroup>
  </Target>

</Project>

Once this project has been added to your incremental generator, you can then use the GenericSymbolReferenceTree.FromIncrementalGeneratorInitializationContext method to get an IncrementalValueProvider which gives you access to the tree. For example:

using Microsoft.CodeAnalysis;

namespace MyProjectGenerator
{
    [Generator]
    internal class MyGenerator : IIncrementalGenerator
    {
        public void Initialize(IncrementalGeneratorInitializationContext context)
        {
            var symbolTree = Monkeymoto.GeneratorUtils.GenericSymbolReferenceTree.FromIncrementalGeneratorInitializationContext(context);
            var symbolToFind = context.CompilationProvider.Select(static (compilation, _) =>
            {
                return compilation.GetTypeByMetadataName("MyProject.MyGenericType`1")!;
            });
            var symbols = symbolTree.Combine(symbolToFind).Select(static (x, cancellationToken) =>
            {
                var (symbolTree, symbolToFind) = x;
                return symbolTree.GetBranchesBySymbol(symbolToFind, cancellationToken);
            });
            // `symbols` is an `IncrementalValueProvider<IEnumerable<GenericSymbolReference>>`
            // this represents each *closed* instance of `MyProject.MyGenericType<T>` in the compilation
            // i.e., `MyProject.MyGenericType<int>`, `MyProject.MyGenericType<double>`, etc.
        }
    }
}

The methods GetBranch and GetBranchesBySymbol are provided by the GenericSymbolReferenceTree, and can be used to retrieve the closed generic symbols used in your project's compilation, each paired with the relevant syntax nodes.