using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;

public class EmitHelloWorld
{
    static void Main(string[] args)
    {
        // create a dynamic assembly and module 
        AssemblyName assemblyName = new AssemblyName();
        assemblyName.Name = "HelloWorld";
        AssemblyBuilder assemblyBuilder = Thread.GetDomain().DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.RunAndSave);
        ModuleBuilder module;
        module = assemblyBuilder.DefineDynamicModule("HelloWorld.exe");

        // create a new type to hold our Main method
        TypeBuilder typeBuilder = module.DefineType("HelloWorldType", TypeAttributes.Public | TypeAttributes.Class);

        // create the Main(string[] args) method
        MethodBuilder methodbuilder = typeBuilder.DefineMethod("Main", MethodAttributes.HideBySig | MethodAttributes.Static |
            MethodAttributes.Public, typeof(void), new Type[] { typeof(string[]) });

        // generate the IL for the Main method
        ILGenerator ilGenerator = methodbuilder.GetILGenerator();
        ilGenerator.EmitWriteLine("hello, world");
        ilGenerator.Emit(OpCodes.Ret);

        // bake it
        Type helloWorldType = typeBuilder.CreateType();

        // run it
        helloWorldType.GetMethod("Main").Invoke(null, new string[] { null });

        // set the entry point for the application and save it
        assemblyBuilder.SetEntryPoint(methodbuilder, PEFileKinds.ConsoleApplication);
        assemblyBuilder.Save("HelloWorld.exe");
    }
}