Move EH personality functions to std
These were previously in the panic_unwind crate with dummy stubs in the
panic_abort crate. However it turns out that this is insufficient: we
still need a proper personality function even with -C panic=abort to
handle the following cases:
1) `extern "C-unwind"` still needs to catch foreign exceptions with -C
panic=abort to turn them into aborts. This requires landing pads and a
personality function.
2) ARM EHABI uses the personality function when creating backtraces.
The dummy personality function in panic_abort was causing backtrace
generation to get stuck in a loop since the personality function is
responsible for advancing the unwind state to the next frame.
Fixes#41004
Without this change, in <https://doc.rust-lang.org/1.63.0/std/#primitives>,
`reference` is the only entry in that list which does not contain the
syntax by which the type is named in source code. With this change, it
contains them, in roughly the same way as the `pointer` entry does.
Extra documentation for new formatting feature
Documentation of this feature was added in #90473 and released in Rust 1.58. However, high traffic macros did not receive new examples. Namely `println!()` and `format!()`.
The doc comments included in Rust are super important to the community- especially newcomers. I have met several other newbies like myself who are unaware of this recent (well about 7 months old now) update to the language allowing for convenient intra-string identifiers.
Bringing small examples of this feature to the doc comments of `println!()` and `format!()` would be helpful to everyone learning the language.
[Blog Post Announcing Feature](https://blog.rust-lang.org/2022/01/13/Rust-1.58.0.html)
[Feature PR](https://github.com/rust-lang/rust/pull/90473) - includes several instances of documentation of the feature- minus the macros in question for this PR
*This is my first time contributing to a project this large. Feedback would mean the world to me 😄*
---
*Recreated; I violated the [No-Merge Policy](https://rustc-dev-guide.rust-lang.org/git.html#no-merge-policy)*
Optimize `Wtf8Buf::into_string` for the case where it contains UTF-8.
Add a `is_known_utf8` flag to `Wtf8Buf`, which tracks whether the
string is known to contain UTF-8. This is efficiently computed in many
common situations, such as when a `Wtf8Buf` is constructed from a `String`
or `&str`, or with `Wtf8Buf::from_wide` which is already doing UTF-16
decoding and already checking for surrogates.
This makes `OsString::into_string` O(1) rather than O(N) on Windows in
common cases.
And, it eliminates the need to scan through the string for surrogates in
`Args::next` and `Vars::next`, because the strings are already being
translated with `Wtf8Buf::from_wide`.
Many things on Windows construct `OsString`s with `Wtf8Buf::from_wide`,
such as `DirEntry::file_name` and `fs::read_link`, so with this patch,
users of those functions can subsequently call `.into_string()` without
paying for an extra scan through the string for surrogates.
r? `@ghost`
Move Error trait into core
This PR moves the error trait from the standard library into a new unstable `error` module within the core library. The goal of this PR is to help unify error reporting across the std and no_std ecosystems, as well as open the door to integrating the error trait into the panic reporting system when reporting panics whose source is an errors (such as via `expect`).
This PR is a rewrite of https://github.com/rust-lang/rust/pull/90328 using new compiler features that have been added to support error in core.
These were previously in the panic_unwind crate with dummy stubs in the
panic_abort crate. However it turns out that this is insufficient: we
still need a proper personality function even with -C panic=abort to
handle the following cases:
1) `extern "C-unwind"` still needs to catch foreign exceptions with -C
panic=abort to turn them into aborts. This requires landing pads and a
personality function.
2) ARM EHABI uses the personality function when creating backtraces.
The dummy personality function in panic_abort was causing backtrace
generation to get stuck in a loop since the personality function is
responsible for advancing the unwind state to the next frame.
Align android `sigaddset` impl with the reference impl from Bionic
In https://github.com/rust-lang/rust/pull/100737 I noticed we were treating the sigset_t as an array of bytes, while referencing code from android (ad8dcd6023/libc/include/android/legacy_signal_inlines.h) which treats it as an array of unsigned long.
That said, the behavior difference is so subtle here that it's not hard to see why nobody noticed. This fixes the implementation to be equivalent to the one in bionic.
Use pointer `is_aligned*` methods
This PR replaces some manual alignment checks with calls to `pointer::{is_aligned, is_aligned_to}` and removes a useless pointer cast.
r? `@scottmcm`
_split off from #100746_
Guarantee `try_reserve` preserves the contents on error
Update doc comments to make the guarantee explicit. However, some
implementations does not have the statement though.
* `HashMap`, `HashSet`: require guarantees on hashbrown side.
* `PathBuf`: simply redirecting to `OsString`.
Fixes#99606.
Rework Ipv6Addr::is_global to check for global reachability rather than global scope - rebase
Rebasing of pull request #86634 off of master to try and get the feature "ip" stabilized.
I also found a test failure in the rebase that is_global was considering the benchmark space to be globally reachable.
This is related to my other rebasing pull request #99947
Std module docs improvements
My primary goal is to create a cleaner separation between primitive types and primitive type helper modules (fixes#92777). I also changed a few header lines in other top-level std modules (seen at https://doc.rust-lang.org/std/) for consistency.
Some conventions used/established:
* "The \`Box\<T>` type for heap allocation." - if a module mainly provides a single type, name it and summarize its purpose in the module header
* "Utilities for the _ primitive type." - this wording is used for the header of helper modules
* Documentation for primitive types themselves are removed from helper modules
* provided-by-core functionality of primitive types is documented in the primitive type instead of the helper module (such as the "Iteration" section in the slice docs)
I wonder if some content in `std::ptr` should be in `pointer` but I did not address this.
Replace most uses of `pointer::offset` with `add` and `sub`
As PR title says, it replaces `pointer::offset` in compiler and standard library with `pointer::add` and `pointer::sub`. This generally makes code cleaner, easier to grasp and removes (or, well, hides) integer casts.
This is generally trivially correct, `.offset(-constant)` is just `.sub(constant)`, `.offset(usized as isize)` is just `.add(usized)`, etc. However in some cases we need to be careful with signs of things.
r? ````@scottmcm````
_split off from #100746_
add miri-test-libstd support to libstd
- The first commit mirrors what we already have in liballoc.
- The second commit adds some regression tests that only really make sense to be run in Miri, since they rely on Miri's extra checks to detect anything.
- The third commit makes the MPSC tests work in reasonable time in Miri by reducing iteration counts.
- The fourth commit silences some warnings due to code being disabled with `cfg(miri)`
Windows: Load synch functions together
Attempt to load all the required sync functions and fail if any one of them fails.
This fixes a FIXME by going back to optional loading of `WakeByAddressSingle`.
Also reintroduces a macro for optional loading of functions but keeps it separate from the fallback macro rather than having that do two different jobs.
r? `@thomcc`
Expose `Utf8Lossy` as `Utf8Chunks`
This PR changes the feature for `Utf8Lossy` from `str_internals` to `utf8_lossy` and improves the API. This is done to eventually expose the API as stable.
Proposal: rust-lang/libs-team#54
Tracking Issue: #99543
Avoid zeroing a 1kb stack buffer on every call to `std::sys::windows::fill_utf16_buf`
I've also tried to be slightly more careful about integer overflows, although in practice this is likely still not handled ideally.
r? `@ChrisDenton`
