macros: allow setting unhandled_panic behavior in tokio::{main, test}

[name1e5s]

Motivation

Allow users to set unhandled_panic behavior in those macros directly.

Close #6527.

Solution

This PR parses unhandled_panic in tokio-macros.

[mox692]

I would like to see the documentation for this. Perhaps it will be placed tokio-macros/src/lib.rs, there should already be similar docs there.

[name1e5s]

I would like to see the documentation for this. Perhaps it will be placed tokio-macros/src/lib.rs, there should already be similar docs there.

Thanks for your suggestion. Documantation is added now.

[mox692]

Overall looks good to me, I left some comments regarding the docs.

[mox692]

For consistency with the other examples on this page, can you use no_run instead of ignore?
(The ignore annotation makes the doc a bit scary.)

[name1e5s]

For consistency with the other examples on this page, can you use no_run instead of ignore? (The ignore annotation makes the doc a bit scary.)

I tried and found it break those CI jobs running cargo test without RUSTFLAGS="--cfg tokio_unstable", such as this link. Since we can't use conditional compilation tricks on examples, I think we can only use ignore here to make CI happy.

[Darksonn]

I'm pretty sure that #[cfg(tokio_unstable)] works perfectly fine inside an example.

[name1e5s]

I'm pretty sure that #[cfg(tokio_unstable)] works perfectly fine inside an example.

Yes, it works fine. I mean we can not use words like

```#[cfg(tokio_unstable)]

to disable an example entirely. But your comment reminds me that we can use # lines to make the example works under cargo test without tokio_unstable , I will try it.

[name1e5s]

I'm pretty sure that #[cfg(tokio_unstable)] works perfectly fine inside an example.

Yes, it works fine. I mean we can not use words like

```#[cfg(tokio_unstable)]

to disable an example entirely. But your comment reminds me that we can use # lines to make the example works under cargo test without tokio_unstable , I will try it.

All tests looks fine now.

[mox692]

Looks good to me, thanks.