Runner.cs

[DllExport("compileandrun")]
public static void Script(IntPtr client, [MarshalAs(UnmanagedType.LPStr)] string args)
{
    if (!InitApi(client))
    {
        return;
    }

    try
    {
        var code = File.ReadAllText(args);

        var basePath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

        using (var codeProvider = new CSharpCodeProvider())
        {
            var parameters = new CompilerParameters(new[]
            {
                "mscorlib.dll",
                "System.Core.dll",
                "Microsoft.CSharp.dll",
                Path.Combine(basePath, "Microsoft.Diagnostics.Runtime.dll"),
                Path.Combine(basePath, "DynaMD.dll")
            });
            parameters.GenerateInMemory = true;

            var results = codeProvider.CompileAssemblyFromSource(parameters, code);

            if (results.Errors.Count > 0)
            {
                Console.WriteLine(string.Join("\r\n", results.Errors.Cast<CompilerError>().Select(l => l.ErrorText)));
                return;
            }

            var type = results.CompiledAssembly.GetType("Test.Program");

            var method = type.GetMethod("Run", BindingFlags.Static | BindingFlags.Public);

            method.Invoke(null, new object[] { Runtime.Heap });
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine("An error occured: " + ex);
    }
}