[backtraces]: look for the `begin` symbol only after seeing `end`
On `x86_64-pc-windows-msvc`, we often get backtraces which look like
this:
```
10: 0x7ff77e0e9be5 - std::panicking::rust_panic_with_hook
11: 0x7ff77e0e11b4 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
12: 0x7ff77e0e116f - std::sys_common::backtrace::__rust_end_short_backtrace::h61c7ecb1b55338ae
13: 0x7ff77e0f89dd - std::panicking::begin_panic::h8e60ef9f82a41805
14: 0x7ff77e0e108c - d
15: 0x7ff77e0e1069 - c
16: 0x7ff77e0e1059 - b
17: 0x7ff77e0e1049 - a
18: 0x7ff77e0e1039 - core::ptr::drop_in_place<std::rt::lang_start<()>::{{closure}}>::h1bfcd14d5e15ba81
19: 0x7ff77e0e1186 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
20: 0x7ff77e0e100c - std::rt::lang_start::{{closure}}::ha054184bbf9921e3
```
Notice that `__rust_begin_short_backtrace` appears on frame 11 before
`__rust_end_short_backtrace` on frame 12. This is because in typical
release binaries without debug symbols, dbghelp.dll, which we use to walk
and symbolize the stack, does not know where CGU internal functions
start or end and so the closure invoked by `__rust_end_short_backtrace`
is incorrectly described as `__rust_begin_short_backtrace` because it
happens to be near that symbol.
While that can obviously change, this has been happening quite
consistently since #75048. Since this is a very small change to the std
and the change makes sense by itself, I think this is worth doing.
This doesn't completely resolve the situation for release binaries on
Windows, since without debug symbols, the stack printed can still show
incorrect symbol names (this is why the test uses `#[no_mangle]`) but it
does slightly improve the situation in that you see the same backtrace
you would see with `RUST_BACKTRACE=full` or in a debugger (without the
uninteresting bits at the top and bottom).
Fixes part of #87481
Fix may not to appropriate might not or must not
I went through and changed occurrences of `may not` to be more explicit with `might not` and `must not`.
On `x86_64-pc-windows-msvc`, we often get backtraces which look like
this:
```
10: 0x7ff77e0e9be5 - std::panicking::rust_panic_with_hook
11: 0x7ff77e0e11b4 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
12: 0x7ff77e0e116f - std::sys_common::backtrace::__rust_end_short_backtrace::h61c7ecb1b55338ae
13: 0x7ff77e0f89dd - std::panicking::begin_panic::h8e60ef9f82a41805
14: 0x7ff77e0e108c - d
15: 0x7ff77e0e1069 - c
16: 0x7ff77e0e1059 - b
17: 0x7ff77e0e1049 - a
18: 0x7ff77e0e1039 - core::ptr::drop_in_place<std::rt::lang_start<()>::{{closure}}>::h1bfcd14d5e15ba81
19: 0x7ff77e0e1186 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5769736bdb11136c
20: 0x7ff77e0e100c - std::rt::lang_start::{{closure}}::ha054184bbf9921e3
```
Notice that `__rust_begin_short_backtrace` appears on frame 11 before
`__rust_end_short_backtrace` on frame 12. This is because in typical
release binaries without debug symbols, dbghelp.dll, which we use to walk
and symbolize the stack, does not know where CGU internal functions
start or end and so the closure invoked by `__rust_end_short_backtrace`
is incorrectly described as `__rust_begin_short_backtrace` because it
happens to be near that symbol.
While that can obviously change, this has been happening quite
consistently since #75048. Since this is a very small change to the std
and the change makes sense by itself, I think this is worth doing.
This doesn't completely resolve the situation for release binaries on
Windows, since without debug symbols, the stack printed can still show
incorrect symbol names (this is why the test uses `#[no_mangle]`) but it
does slightly improve the situation in that you see the same backtrace
you would see with `RUST_BACKTRACE=full` or in a debugger (without the
uninteresting bits at the top and bottom).
I looked in stdlib and as @BurntSushi thought, `raw` is generally
used for raw pointers, or other hazardous kinds of thing. stdlib does
not have `into_parts` apart from the one I added to `IntoInnerError`.
I did an ad-hoc search of the rustdocs for my current game project
Otter, which includes quite a large number of dependencies.
`into_parts` seems heavily used for things quite like this.
So change this name.
Suggested-by: Andrew Gallant <jamslam@gmail.com>
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
I didn't notice the submodule, which means I failed to re-export this
to make it actually-public.
Reported-by: Andrew Gallant <jamslam@gmail.com>
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
Make const panic!("..") work in Rust 2021.
During const eval, this replaces calls to core::panicking::panic_fmt and std::panicking::being_panic_fmt with a call to a new const fn: core::panicking::const_panic_fmt. That function uses fmt::Arguments::as_str() to get the str and calls panic_str with that instead.
panic!() invocations with formatting arguments are still not accepted, as the creation of such a fmt::Arguments cannot be done in constant functions right now.
r? `@RalfJung`
Stabilize core::task::ready!
_Tracking issue: https://github.com/rust-lang/rust/issues/70922_
This PR stabilizes the `task::ready!` macro. Similar to https://github.com/rust-lang/rust/pull/80886, this PR was waiting on https://github.com/rust-lang/rust/issues/74355 to be fixed.
The `task::ready!` API has existed in the futures ecosystem for several years, and was added on nightly last year in https://github.com/rust-lang/rust/pull/70817. The motivation for this macro is the same as it was back then: virtually every single manual future implementation makes use of this; so much so that it's one of the few things included in the [futures-core](https://docs.rs/futures-core/0.3.12/futures_core) library.
r? ``@tmandry``
cc/ ``@rust-lang/wg-async-foundations`` ``@rust-lang/libs``
## Example
```rust
use core::task::{Context, Poll};
use core::future::Future;
use core::pin::Pin;
async fn get_num() -> usize {
42
}
pub fn do_poll(cx: &mut Context<'_>) -> Poll<()> {
let mut f = get_num();
let f = unsafe { Pin::new_unchecked(&mut f) };
let num = ready!(f.poll(cx));
// ... use num
Poll::Ready(())
}
```
During const eval, this replaces calls to core::panicking::panic_fmt and
std::panicking::being_panic_fmt with a call to a new const fn:
core::panicking::const_panic_fmt. That function uses
fmt::Arguments::as_str() to get the str and calls panic_str with that
instead.
panic!() invocations with formatting arguments are still not accepted,
as the creation of such a fmt::Arguments cannot be done in constant
functions right now.
Use hashbrown's `extend_reserve()` in `HashMap`
When we added `extend_reserve()` to our implementation of `Extend` for `HashMap`, hashbrown didn't have a version we could use. Now that hashbrown has added it, we should use its version instead of implementing it ourself.
Update VxWork's UNIX support
1. VxWorks does not provide glibc
2. VxWorks does provide `sigemptyset` and `sigaddset`
Note: these changes are concurrent to [this PR](https://github.com/rust-lang/libc/pull/2295) in libc.
Stabilize `impl From<[(K, V); N]> for HashMap` (and friends)
In addition to allowing HashMap to participate in Into/From conversion, this adds the long-requested ability to use constructor-like syntax for initializing a HashMap:
```rust
let map = HashMap::from([
(1, 2),
(3, 4),
(5, 6)
]);
```
This addition is highly motivated by existing precedence, e.g. it is already possible to similarly construct a Vec from a fixed-size array:
```rust
let vec = Vec::from([1, 2, 3]);
```
...and it is already possible to collect a Vec of tuples into a HashMap (and vice-versa):
```rust
let vec = Vec::from([(1, 2)]);
let map: HashMap<_, _> = vec.into_iter().collect();
let vec: Vec<(_, _)> = map.into_iter().collect();
```
...and of course it is likewise possible to collect a fixed-size array of tuples into a HashMap ([but not vice-versa just yet](https://github.com/rust-lang/rust/issues/81615)):
```rust
let arr = [(1, 2)];
let map: HashMap<_, _> = std::array::IntoIter::new(arr).collect();
```
Therefore this addition seems like a no-brainer.
As for any impl, this would be insta-stable.
Stabilize `into_parts()` and `into_error()`
This stabilizes `IntoInnerError`'s `into_parts()` and `into_error()` methods, currently gated behind the `io_into_inner_error_parts` feature. The FCP has [already completed.](https://github.com/rust-lang/rust/issues/79704#issuecomment-880652967)
Closes#79704.
Document iteration order of `retain` functions
For `HashSet` and `HashMap`, this simply copies the comment from
`BinaryHeap::retain`.
For `BTreeSet` and `BTreeMap`, this adds an additional guarantee that
wasn't previously documented. I think that because these data structures
are inherently ordered and other functions guarantee ordered iteration,
it makes sense to provide this guarantee for `retain` as well.
Add comments explaining the unix command-line argument support.
Following up on #87236, add comments to the unix command-line argument
support explaining that the code doesn't mutate the system-provided
argc/argv, and that this is why the code doesn't need a lock or special
memory ordering.
r? ```@RalfJung```
add `Stdin::lines`, `Stdin::split` forwarder methods
Add forwarder methods `Stdin::lines` and `Stdin::split`, which consume
and lock a `Stdin` handle, and forward on to the corresponding `BufRead`
methods. This should make it easier for beginners to use those iterator
constructors without explicitly dealing with locks or lifetimes.
Replaces #86412.
~~Based on #86846 to get the tracking issue number for the `stdio_locked` feature.~~ Rebased after merge, so it's only one commit now.
r? `@joshtriplett`
`@rustbot` label +A-io +C-enhancement +D-newcomer-roadblock +T-libs-api
Following up on #87236, add comments to the unix command-line argument
support explaining that the code doesn't mutate the system-provided
argc/argv, and that this is why the code doesn't need a lock or special
memory ordering.
Simplify command-line argument initialization on unix
Simplify Rust's command-line argument initialization code on unix:
- The cleanup code isn't needed, because it was just zeroing out non-owning variables at runtime cleanup time. After 91c3eee173, Rust's command-line initialization code on unix no longer allocates `CString`s and a `Vec` at startup time.
- The `Mutex` isn't needed; if there's somehow a call to `args()` before argument initialization has happened, the code returns return an empty list, which we can do with a null check.
With these changes, a simple cdylib that doesn't use threads avoids getting `pthread_mutex_lock`/`pthread_mutex_unlock` in its symbol table.
Move asm! and global_asm! to core::arch
Follow-up to https://github.com/rust-lang/stdarch/pull/1183 .
Implements the libs-api team decision from rust-lang/rust#84019 (comment) .
In order to not break nightly users, this PR also adds the newly-moved items to the prelude. However, a decision will need to be made before stabilization as to whether these items should remain in the prelude. I will file an issue for this separately.
Fixes#84019 .
r? `@Amanieu`
Add diagnostic items for Clippy
This adds a bunch of diagnostic items to `std`/`core`/`alloc` functions, structs and traits used in Clippy. The actual refactorings in Clippy to use these items will be done in a different PR in Clippy after the next sync.
This PR doesn't include all paths Clippy uses, I've only gone through the first 85 lines of Clippy's [`paths.rs`](ecf85f4bdc/clippy_utils/src/paths.rs) (after rust-lang/rust-clippy#7466) to get some feedback early on. I've also decided against adding diagnostic items to methods, as it would be nicer and more scalable to access them in a nicer fashion, like adding a `is_diagnostic_assoc_item(did, sym::Iterator, sym::map)` function or something similar (Suggested by `@camsteffen` [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/147480-t-compiler.2Fwg-diagnostics/topic/Diagnostic.20Item.20Naming.20Convention.3F/near/225024603))
There seems to be some different naming conventions when it comes to diagnostic items, some use UpperCamelCase (`BinaryHeap`) and some snake_case (`hashmap_type`). This PR uses UpperCamelCase for structs and traits and snake_case with the module name as a prefix for functions. Any feedback on is this welcome.
cc: rust-lang/rust-clippy#5393
r? `@Manishearth`
In the command-line argument initialization code, remove the Mutex
around the `ARGV` and `ARGC` variables, and simply check whether
ARGV is non-null before dereferencing it. This way, if either of
ARGV or ARGC is not initialized, we'll get an empty argument list.
This allows simple cdylibs to avoid having
`pthread_mutex_lock`/`pthread_mutex_unlock` appear in their symbol
tables if they don't otherwise use threads.
