Sergio0694

public static IReadOnlyList<FieldInfo> CollectFields(Delegate instance)
{
    // Local, recursive function to explore the closure type
    IEnumerable<FieldInfo> CollectFields(Type type)
    {
        foreach (FieldInfo field in type.GetFields())
        {
            if (field.Name.StartsWith("CS$<>")) // Nested closure type
            {
                foreach (FieldInfo nested in CollectFields(field.FieldType))

Sergio0694

public static void Main()
{
    int[] array = new int[10];
    int value = 1;

    Action<int> action = i => array[i] = value;

    foreach (FieldInfo field in CollectFields(action))
    {
        Console.WriteLine($"{field.Name}: {field.GetValue(action.Target)}");

Sergio0694

public sealed class ClosureField
{
    public FieldInfo Info { get; }
    public IReadOnlyList<FieldInfo> Parents { get; }

    public ClosureField(FieldInfo info, IReadOnlyList<FieldInfo> parents)
    {
        Info = info;
        Parents = parents;
    }

Sergio0694

public static void Main()
{
    int[] array = new int[10];
    {
        int value = 1;

        Action<int> action = i => array[i] = value;

        foreach (var field in CollectFields(action))
        {

Sergio0694

public static unsafe (object[] References, byte[] Bytes) GetData(
    Delegate instance, IReadOnlyList<ClosureField> fields)
{
    // Calculate how many bytes we need
    int
        referenceCount = 0,
        byteSize = 0;
    foreach (var field in fields)
    {
        if (field.Info.FieldType.IsValueType)

Sergio0694

# C#
public static object GetFieldXForVector2(object obj)
{
    Vector2 instance = (Vector2)obj;
    return instance.X;
}

# IL (simplified)
public static object GetFieldXForVector2(object obj)
{

Sergio0694

// C#
public static int MultiplyAndAddOne(int a, int b)
{
    int temp = a * b;
    return temp + 1;
}

// IL (simplified)
public static int32 MultiplyAndAddOne(int32 a, int32 b)
{

Sergio0694

private static Func<object, object> BuildDynamicGetter(ClosureField field)
{
    // Create a new dynamic method
    Type ownerType = field.Info.DeclaringType;
    DynamicMethod method = new DynamicMethod(
        $"Get{field.Info.Name}",
        typeof(object),             // The return type
        new [] { typeof(object) },  // A single object parameter
        ownerType);                 // The type that will own the new method

Sergio0694

public static Func<object, object> BuildDynamicGetter(ClosureField field)
{
    // Create a new dynamic method
    FieldInfo[] hierarchy = field.Parents.Append(field.Info).ToArray();
    Type ownerType = hierarchy[0].DeclaringType;
    DynamicMethod method = new DynamicMethod(
        $"Get{field.Info.Name}",
        typeof(object),             // The return type
        new[] { typeof(object) },   // A single object parameter
        ownerType);                 // The type that will own the new method

Sergio0694

public static void EmitStoreLocal(this ILGenerator il, int index)
{
    if (index <= 3)
    {
        il.Emit(index switch
        {
            0 => OpCodes.Stloc_0,
            1 => OpCodes.Stloc_1,
            2 => OpCodes.Stloc_2,
            3 => OpCodes.Stloc_3,