c# - 源生成器在同一项目中看不到类

Question

我有一个源生成器，它看起来像这样:

public class Generator : ISourceGenerator
{

    public Generator()
    {
        // Uncomment if you want to debug this
        Debugger.Launch();
    }
    public void Initialize(GeneratorInitializationContext context)
    {
        context.RegisterForSyntaxNotifications(() => new MySyntaxReceiver());
    }

    public void Execute(GeneratorExecutionContext context)
    {
        var syntaxReceiver = (MySyntaxReceiver)context.SyntaxReceiver;

        var responseMessageClasses = syntaxReceiver.ResponseMessageClasses;
        // do stuff to responseMessageClasses
    }
}

internal class MySyntaxReceiver : ISyntaxReceiver
{
    public List<ClassDeclarationSyntax> ResponseMessageClasses { get; private set; } = new List<ClassDeclarationSyntax>();

    public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
    {
        if (syntaxNode is ClassDeclarationSyntax cds &&
            cds.Identifier.ValueText.EndsWith("ResponseMessage", StringComparison.OrdinalIgnoreCase))
        {
            ResponseMessageClasses.Add(cds);
        }
    }
}

在同一个项目中，我有一个简单类的文件夹，其名称均以“ResponseMessage”结尾。这些类仅具有 string、int 和 bool 等简单类型作为属性。它们与 SourceGenerator 位于不同的命名空间中。

还有第二个控制台应用程序项目引用我的源生成器作为分析器。当我构建项目时，我可以成功侵入 SourceGenerator 代码。

问题:我的 SyntaxReceiver 类永远看不到简单的 ResponseMessage 类。 OnVisitSyntaxNode 方法仅命中 Program.cs 文件。这是怎么回事？

Answer 1

根据设计，不可能在定义源生成器的程序集中使用源生成器。根据the design spec :

Generator implementations are defined in external assemblies passed to the compiler using the same -analyzer: option used for diagnostic analyzers.

...

Since generators are loaded from external assemblies, a generator cannot be used to build the assembly in which it is defined.