add regression test for try!
Our widespread internal use of `try` was like a regression test. Now that most of `try!`s have been converted to `?`, lets add a proper regression test.
cc @bstrie
Flatten rustc and rustc_trans module hierarchy slightly.
The following moves were made, in the name of sanity/simplicity:
* `rustc::middle::{cfg, infer, traits, ty}` to `rustc::{cfg, infer, traits, ty}`
* `rustc::middle::subst` to `rustc::ty::subst`
* `rustc_trans::trans::*` to `rustc_trans::*`
* `rustc_trans::save` to `rustc_save_analysis` (cc @nrc)
I've rebased a larger WIP branch on top of this and the only conflicts were in imports, but YMMV.
Adding these "known" values to the table of used ids is only required
when embedding markdown into a rustdoc html page and may yield
unexpected results when rendering a standalone `*.md` file.
This adds checks to ensure that:
* link anchors refer to existing id's on the target page
* id's are unique within an html document
* page redirects are valid
std: Rewrite Once with poisoning
This commit rewrites the `std::sync::Once` primitive with poisoning in mind in
light of #31688. Currently a panic in the initialization closure will cause
future initialization closures to run, but the purpose of a Once is usually to
initialize some global state so it's highly likely that the global state is
corrupt if a panic happened. The same strategy of a mutex is taken where a panic
is propagated by default.
A new API, `call_once_force`, was added to subvert panics like is available on
Mutex as well (for when panicking is handled internally).
Adding this support was a significant enough change to the implementation that
it was just completely rewritten from scratch, primarily to avoid using a
`StaticMutex` which needs to have `destroy()` called on it at some point (a pain
to do).
Closes#31688
This commit rewrites the `std::sync::Once` primitive with poisoning in mind in
light of #31688. Currently a panic in the initialization closure will cause
future initialization closures to run, but the purpose of a Once is usually to
initialize some global state so it's highly likely that the global state is
corrupt if a panic happened. The same strategy of a mutex is taken where a panic
is propagated by default.
A new API, `call_once_force`, was added to subvert panics like is available on
Mutex as well (for when panicking is handled internally).
Adding this support was a significant enough change to the implementation that
it was just completely rewritten from scratch, primarily to avoid using a
`StaticMutex` which needs to have `destroy()` called on it at some point (a pain
to do).
Closes#31688
(1) In contrast to `that`, `so that` expresses `result` indicated by the sentence, not `reason`;
(2) `block` is an expression, and may be have an expression, so I add `optional an expression` to make more precise;
(3) When I read here, I was confused with what `the child` referred to. After modification, it would be better.
Add note on `str` being an unsized type in strings section of book
The book section on Rust strings mentions `&str` and `String` but does not address why `str` is not used directly. This adds a short blurb and a link to the unsized types chapter. The second draft of the book will go more in-depth on this, but this should help a bit for now. Thanks #rust for clarifying this point, and let me know if it needs rewording or different placement 😄.
CC @steveklabnik @Kimundi
Document heap allocation location guarantee
```
14:25 < aidanhs> is there any guarantee that boxes will not move the value on the heap when they are moved?
14:26 <@steveklabnik> aidanhs: ... i'm not sure if it's a guarantee, but it follows, generally
14:26 <@steveklabnik> aidanhs: moves mean memcpy, so you're memcpying the structure of the box itself, which is copying the pointer
14:26 <@steveklabnik> so the pointer won't be updated
14:26 <@steveklabnik> moves cannot do complex things like move the memory around on the heap
14:26 <@kmc> aidanhs: I would say it's guaranteed
14:27 < aidanhs> steveklabnik: yeah, that's what I was thinking, it'd be pretty strange for rust to do something, but I couldn't find any docs one way or the other
14:27 <@steveklabnik> kmc: aidanhs yeah, it's like a borderline thing that we don't explicitly guanratee but i think IS guaranteed by our other guarantees
14:27 <@steveklabnik> mostly that move == memcpy
14:28 < aidanhs> kmc: steveklabnik great thanks! would a PR to the rust reference along these lines be ok?
14:28 < jmesmon> aidanhs: I believe owning_ref has some discussion of that (stable references)
14:29 <@steveklabnik> aidanhs: i would probably take that, yeah
14:29 < aidanhs> jmesmon: thanks, I'll take a look at that
```
https://botbot.me/mozilla/rust/2016-02-22/?msg=60657619&page=18
r? @steveklabnik
The `println!` calls in the previous version were never shown (at least
not in the playpen) because the main thread is finished before all the
spawned child threads were synchronized. This commit adds a join for
each thread handle to wait in the main thread until all child threads
are finished.
