C＃拼图：可达到goto指向无法访问的标签(C# Puzzle : Reachable goto pointing to an unreachable label)

C＃拼图：可达到goto指向无法访问的标签(C# Puzzle : Reachable goto pointing to an unreachable label)

这里是Eric Lippert从这篇文章发表的评论：

现在你知道答案了，你可以解决这个难题：给我写一个程序，其中有一个可到达的goto，它转到一个无法访问的标签。 - Eric Lippert 7月17日7:17

我无法创建一个代码，它可能会指向无法访问的标签。 这甚至有可能吗？ 如果是的话，那么C＃代码会是什么样子？

注意：我们不要讨论'goto'如何坏等。这是一个理论练习。

Here's Eric Lippert's comment from this post:

Now that you know the answer, you can solve this puzzle: write me a program in which there is a reachable goto which goes to an unreachable label. – Eric Lippert Jul 17 at 7:17

I am not able to create a code which will have reachable goto pointing to an unreachable label. Is that even possible? If yes, what would the C# code look like?

Note: Let's not get into discussion about how 'goto' is bad etc. This is a theoretical exercise.

最满意答案

我原来的答案是：

try { goto ILikeCheese; } finally { throw new InvalidOperationException("You only have cottage cheese."); } ILikeCheese: Console.WriteLine("MMM. Cheese is yummy.");

这里没有编译器警告。

bool jumping = false; try { if (DateTime.Now < DateTime.MaxValue) { jumping = (Environment.NewLine != "\t"); goto ILikeCheese; } return; } finally { if (jumping) throw new InvalidOperationException("You only have cottage cheese."); } ILikeCheese: Console.WriteLine("MMM. Cheese is yummy.");

My original answer:

try { goto ILikeCheese; } finally { throw new InvalidOperationException("You only have cottage cheese."); } ILikeCheese: Console.WriteLine("MMM. Cheese is yummy.");

Here is without the compiler warning.

bool jumping = false; try { if (DateTime.Now < DateTime.MaxValue) { jumping = (Environment.NewLine != "\t"); goto ILikeCheese; } return; } finally { if (jumping) throw new InvalidOperationException("You only have cottage cheese."); } ILikeCheese: Console.WriteLine("MMM. Cheese is yummy.");