如何使用Roslyn判断某个变量是否在某个语法节点的作用域内？

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;

public bool IsVariableInScope(SyntaxNode root, string variableName, SyntaxNode targetNode)
{
    // 获取语义模型
    SemanticModel semanticModel = GetSemanticModel(root);

    // 获取目标变量的符号信息
    ISymbol variableSymbol = semanticModel.GetSymbolInfo(targetNode).Symbol;

    // 遍历语法节点，查找目标变量的作用域范围
    foreach (SyntaxNode node in root.DescendantNodes())
    {
        // 判断语法节点的位置范围是否包含目标变量的作用域范围
        if (node.Span.Contains(targetNode.Span) && semanticModel.GetDeclaredSymbol(node) == variableSymbol)
        {
            return true;
        }
    }

    return false;
}

public SemanticModel GetSemanticModel(SyntaxNode root)
{
    // 创建编译对象
    Compilation compilation = CSharpCompilation.Create("temp")
        .AddReferences(MetadataReference.CreateFromFile(typeof(object).Assembly.Location))
        .AddSyntaxTrees(root.SyntaxTree);

    // 获取语义模型
    return compilation.GetSemanticModel(root.SyntaxTree);
}

// 使用示例
string sourceCode = @"
class Program
{
    void TestMethod()
    {
        int x = 10;
        {
            int y = 20;
            // 判断变量y是否在语法节点内
            bool isInScope = IsVariableInScope(root, ""y"", targetNode);
        }
    }
}";

SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(sourceCode);
SyntaxNode root = syntaxTree.GetRoot();
SyntaxNode targetNode = root.DescendantNodes().First(node => node is VariableDeclaratorSyntax && ((VariableDeclaratorSyntax)node).Identifier.Text == "y");

bool isInScope = IsVariableInScope(root, "y", targetNode);