unboxing-visitor.cs

using System;
using System.IO;
using System.Linq;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Text;

public static class Program
{
    public static void Main()
    {
        Visit();
        Console.ReadKey();
    }

    private static async void Visit()
    {
        //string loc = @"C:\prj\coreclr-egor\src\System.Private.CoreLib";
        string loc = @"C:\prj\corefx-egor\src";
        foreach (string path in Directory.EnumerateFiles(loc, "*.cs", SearchOption.AllDirectories))
        {
            if (path.Contains("tests"))
                continue;

            string text = File.ReadAllText(path);
            using (var workspace = new AdhocWorkspace())
            {
                Project proj = workspace.AddProject("UnboxingVisitor", LanguageNames.CSharp).WithMetadataReferences(new[] { MetadataReference.CreateFromFile(typeof(object).Assembly.Location) });
                Document doc = proj.AddDocument(Path.GetFileName(path), SourceText.From(text));
                Compilation compilation = await doc.Project.GetCompilationAsync();
                SyntaxNode root = await doc.GetSyntaxRootAsync();

                var visitor = new UnboxingVisitor { _model = compilation.GetSemanticModel(root.SyntaxTree) };
                SyntaxNode node = visitor.Visit(root);
            }
        }
        Console.WriteLine("End.");
    }
}

internal sealed class UnboxingVisitor : CSharpSyntaxRewriter
{
    internal SemanticModel _model;

    public override SyntaxNode VisitCastExpression(CastExpressionSyntax node)
    {
        var typeToCast = node.Type as IdentifierNameSyntax;
        var whatToCast = node.Expression as IdentifierNameSyntax;

        if (typeToCast != null && whatToCast != null)
        {
            string toType = GetTypeName(typeToCast, _model, out bool isToValueType);
            string fromType = GetTypeName(whatToCast, _model, out bool isFromValueType);

            if (fromType == "Object" && isToValueType)
            {
                var location = node.GetLocation();
                var logStr = $"{location.SourceTree.FilePath}:{location.GetLineSpan().StartLinePosition.Line}     {node.Parent.Parent.ToFullString()}";
                Console.WriteLine(logStr);
                //File.AppendAllText(@"C:\Users\bogat\source\log4.txt", logStr + Environment.NewLine);
            }
        }

        return base.VisitCastExpression(node);
    }

    public static string GetTypeName(ExpressionSyntax es, SemanticModel model, out bool isValueType)
    {
        isValueType = false;
        try
        {
            var symbolInfo = model.GetSymbolInfo(es);
            var symbol = symbolInfo.Symbol as ITypeSymbol;
            isValueType = symbol?.IsValueType == true;

            var aa = symbolInfo.Symbol as IParameterSymbol;
            var type = aa?.Type?.Name ?? symbol?.Name;

            return type;
        }
        catch (Exception exc)
        {
            return null;
        }
    }
}