remove redundant imports
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and removing redundant imports code into two PR.
r? `@petrochenkov`
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
Add emulated TLS support
This is a reopen of https://github.com/rust-lang/rust/pull/96317 . many android devices still only use 128 pthread keys, so using emutls can be helpful.
Currently LLVM uses emutls by default for some targets (such as android, openbsd), but rust does not use it, because `has_thread_local` is false.
This commit has some changes to allow users to enable emutls:
1. add `-Zhas-thread-local` flag to specify that std uses `#[thread_local]` instead of pthread key.
2. when using emutls, decorate symbol names to find thread local symbol correctly.
3. change `-Zforce-emulated-tls` to `-Ztls-model=emulated` to explicitly specify whether to generate emutls.
r? `@Amanieu`
Currently LLVM uses emutls by default
for some targets (such as android, openbsd),
but rust does not use it, because `has_thread_local` is false.
This commit has some changes to allow users to enable emutls:
1. add `-Zhas-thread-local` flag to specify
that std uses `#[thread_local]` instead of pthread key.
2. when using emutls, decorate symbol names
to find thread local symbol correctly.
3. change `-Zforce-emulated-tls` to `-Ztls-model=emulated`
to explicitly specify whether to generate emutls.
Use `unwinding` crate for unwinding on Xous platform
This patch adds support for using [unwinding](https://github.com/nbdd0121/unwinding) on platforms where libunwinding isn't viable. An example of such a platform is `riscv32imac-unknown-xous-elf`.
### Background
The Rust project maintains a fork of llvm at [llvm-project](https://github.com/rust-lang/llvm-project/) where it applies patches on top of the llvm project. This mostly seems to be to get unwinding support for the SGX project, and there may be other patches that I'm unaware of.
There is a lot of machinery in the build system to support compiling `libunwind` on other platforms, and I needed to add additional patches to llvm in order to add support for Xous.
Rather than continuing down this path, it seemed much easier to use a Rust-based library. The `unwinding` crate by `@nbdd0121` fits this description perfectly.
### Future work
This could potentially replace the custom patches for `libunwind` on other platforms such as SGX, and could enable unwinding support on many more exotic platforms.
### Anti-goals
This is not designed to replace `libunwind` on tier-one platforms or those where unwinding support already exists. There is already a well-established approach for unwinding there. Instead, this aims to enable unwinding on new platforms where C++ code may be difficult to compile.
The main() function takes an argument that contains the eh_frame
address. Implement `unwinding` support by looking for unwinding data at
this address.
Signed-off-by: Sean Cross <sean@xobs.io>
std: Invert logic for inclusion of `sys_common::net`
The `library/std/src/sys_common/net.rs` module is intended to define common implementations of networking-related APIs across a variety of platforms that share similar APIs (e.g. Berkeley-style sockets and all). This module is not included for more fringe targets however such as UEFI or "unknown" targets to libstd (those classified as `restricted-std`). Previously the `sys_common/net.rs` file was set up such that an allow-list indicated it shouldn't be used. This commit inverts the logic to have an allow-list of when it should be used instead.
The goal of this commit is to make it a bit easier to experiment with a new Rust target. Currently more esoteric targets are required to get an exception in this `cfg_if` block to use `crate::sys::net` such as for unsupported targets. With this inversion of logic only targets which actually support networking will be listed, where most of those are lumped under `cfg(unix)`.
Given that this change is likely to cause some breakage for some target by accident I've attempted to be somewhat robust with this by following these steps to defining the new predicate for inverted logic.
1. Take all supported targets and filter out all `cfg(unix)` ones as these should all support `sys_common/net.rs`.
2. Take remaining targets and filter out `cfg(windows)` ones.
3. The remaining dozen-or-so targets were all audited by hand. Mostly this included `target_os = "hermit"` and `target_os = "solid_asp3"` which required an allow-list entry, but remaining targets were all already excluded (didn't use `sys_common/net.rs` so they were left out.
If this causes breakage it should be relatively easy to fix and I'd be happy to follow-up with any PRs necessary.
move exposed-provenance APIs into separate feature gate
We have already stated explicitly for all the 'exposed' functions that
> Using this method means that code is *not* following strict provenance rules.
However, they were part of the same feature gate and still described as part of the strict provenance experiment. Unfortunately, their semantics are much less clear and certainly nowhere near stabilization, so in preparation for an attempt to stabilize the strict provenance APIs, I suggest we split the things related to "exposed" into their own feature gate. I also used this opportunity to better explain how Exposed Provenance fits into the larger plan here: this is *one possible candidate* for `as` semantics, but we don't know if it is actually viable, so we can't really promise that it is equivalent to `as`. If it works out we probably want to make `as` equivalent to the 'exposed' APIs; if it doesn't, we will remove them again and try to find some other semantics for `as`.
Add substring API for `OsStr`
This adds a method for taking a substring of an `OsStr`, which in combination with [`OsStr::as_encoded_bytes()`](https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.as_encoded_bytes) makes it possible to implement most string operations in safe code.
API:
```rust
impl OsStr {
pub fn slice_encoded_bytes<R: ops::RangeBounds<usize>>(&self, range: R) -> &Self;
}
```
Motivation, examples and research at https://github.com/rust-lang/libs-team/issues/306.
Tracking issue: #118485
cc `@epage`
r? libs-api
The `library/std/src/sys_common/net.rs` module is intended to define
common implementations of networking-related APIs across a variety of
platforms that share similar APIs (e.g. Berkeley-style sockets and all).
This module is not included for more fringe targets however such as UEFI
or "unknown" targets to libstd (those classified as `restricted-std`).
Previously the `sys_common/net.rs` file was set up such that an
allow-list indicated it shouldn't be used. This commit inverts the logic
to have an allow-list of when it should be used instead.
The goal of this commit is to make it a bit easier to experiment with a
new Rust target. Currently more esoteric targets are required to get an
exception in this `cfg_if` block to use `crate::sys::net` such as for
unsupported targets. With this inversion of logic only targets which
actually support networking will be listed, where most of those are
lumped under `cfg(unix)`.
Given that this change is likely to cause some breakage for some target
by accident I've attempted to be somewhat robust with this by following
these steps to defining the new predicate for inverted logic.
1. Take all supported targets and filter out all `cfg(unix)` ones as
these should all support `sys_common/net.rs`.
2. Take remaining targets and filter out `cfg(windows)` ones.
3. The remaining dozen-or-so targets were all audited by hand. Mostly
this included `target_os = "hermit"` and `target_os = "solid_asp3"`
which required an allow-list entry, but remaining targets were all
already excluded (didn't use `sys_common/net.rs` so they were left
out.
If this causes breakage it should be relatively easy to fix and I'd be
happy to follow-up with any PRs necessary.
Implement thread parking for xous
This follows the pattern set by [the Windows parker](ddef56d5df/library/std/src/sys/windows/thread_parking.rs) when it uses keyed events. An atomic variable is used to track the state and optimize the fast path, while notifications are send via the ticktime server to block and unblock the thread.
ping `@xobs`
`@rustbot` label +T-libs +A-atomic
r? libs
unify read_to_end and io::copy impls for reading into a Vec
This ports over the initial probe (to avoid allocation) and the dynamic read sizing from the io::copy specialization to the `default_read_to_end` implementation which already had its own optimizations for different cases.
I think it should be a best-of-both now.
suggested by `@a1phyr` in https://github.com/rust-lang/rust/pull/117576#issuecomment-1803408492
Use an absolute path to the NUL device
While a bare "NUL" *should* be redirected to the NUL device, especially in this simple case, let's be explicit that we aren't opening a file called "NUL" and instead open it directly.
This will also set a good example for people copying std code.
r? libs
Update windows-bindgen and define `INVALID_HANDLE_VALUE` ourselves
We generate bindings to the Windows API via the `windows-bindgen` crate, which is ultimately what's also used to generate the `windows-sys` and `windows` crates. However, there currently is some custom sauce just for std which makes it a bit different from the vanilla bindings. I would love for us to reduce and eventually remove the differences entirely so that std is using the exact same bindings as everyone else. Maybe in the future we can even just have a normal dependency on `windows-sys`.
This PR removes one of those special things. Our definition of `INVALID_HANDLE_VALUE` relies on an experimental nightly feature for strict provenance, so lets bring that back in house. It also excludes it from the codegen step though that isn't strictly necessary as we override it in any case.
This PR also updates windows-bingen to 0.52.0.
Improve rewind documentation
The persistent use of an internal cursor for readers is expected for buffer data types that aren't read all at once, but for files it leads to the confusing situation where calling `read_to_end` on the same file handle multiple times only returns the contents of the file for the first call. This PR adds a note to the documentation clarifying that in that case, `rewind()` must first be called.
I'm unsure if this is the right location for the docs update. Maybe it should also be duplicated on `File`?
kmc-solid: I/O safety
Adds the I/O safety API (#87329) for socket file descriptors in [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets. All new public items are gated by the `solid_ext` library feature.
This PR adds the following public types and traits:
std::os::solid::io::AsFd
std::os::solid::io::BorrowedFd
std::os::solid::io::OwnedFd
std::os::solid::prelude::AsFd (re-export)
std::os::solid::prelude::BorrowedFd (re-export)
std::os::solid::prelude::OwnedFd (re-export)
And trait implementations:
From<std::net::TcpListener> for std::os::solid::io::OwnedFd
From<std::net::TcpStream> for std::os::solid::io::OwnedFd
From<std::net::UdpSocket> for std::os::solid::io::OwnedFd
From<std::os::solid::io::OwnedFd> for std::net::TcpListener
From<std::os::solid::io::OwnedFd> for std::net::TcpStream
From<std::os::solid::io::OwnedFd> for std::net::UdpSocket
std::fmt::Debug for std::os::solid::io::BorrowedFd<'_>
std::fmt::Debug for std::os::solid::io::OwnedFd
std::io::IsTerminal for std::os::solid::io::BorrowedFd<'_>
std::io::IsTerminal for std::os::solid::io::OwnedFd
std::os::fd::AsRawFd for std::os::solid::io::BorrowedFd<'_>
std::os::fd::AsRawFd for std::os::solid::io::OwnedFd
std::os::fd::FromRawFd for std::os::solid::io::OwnedFd
std::os::fd::IntoRawFd for std::os::solid::io::OwnedFd
std::os::solid::io::AsFd for &impl std::os::solid::io::AsFd
std::os::solid::io::AsFd for &mut impl std::os::solid::io::AsFd
std::os::solid::io::AsFd for Arc<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for Box<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for Rc<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for std::net::TcpListener
std::os::solid::io::AsFd for std::net::TcpStream
std::os::solid::io::AsFd for std::net::UdpSocket
std::os::solid::io::AsFd for std::os::solid::io::BorrowedFd<'_>
std::os::solid::io::AsFd for std::os::solid::io::OwnedFd
Taking advantage of the above change, this PR also refactors the internal details of `std::sys::solid::net` to match the design of other targets, e.g., by redefining `Socket` as a newtype of `OwnedFd`.
This is where our Windows API bindings previously (and incorrectly) used `*mut` instead of `*const` pointers. Now that the bindings have been corrected, the mutable references (which auto-convert to `*mut`) are unnecessary and we can use shared references.
While a bare "NUL" *should* be redirected to the NUL device, especially in this simple case, let's be explicit that we aren't opening a file called "NUL" and instead open it directly.
This will also set a good example for people copying std code.
Adjust frame IP in backtraces relative to image base for SGX target
This is followup to https://github.com/rust-lang/backtrace-rs/pull/566.
The backtraces printed by `panic!` or generated by `std::backtrace::Backtrace` in SGX target are not usable. The frame addresses need to be relative to image base address so they can be used for symbol resolution. Here's an example panic backtrace generated before this change:
```
$ cargo r --target x86_64-fortanix-unknown-sgx
...
stack backtrace:
0: 0x7f8fe401d3a5 - <unknown>
1: 0x7f8fe4034780 - <unknown>
2: 0x7f8fe401c5a3 - <unknown>
3: 0x7f8fe401d1f5 - <unknown>
4: 0x7f8fe401e6f6 - <unknown>
```
Here's the same panic after this change:
```
$ cargo +stage1 r --target x86_64-fortanix-unknown-sgx
stack backtrace:
0: 0x198bf - <unknown>
1: 0x3d181 - <unknown>
2: 0x26164 - <unknown>
3: 0x19705 - <unknown>
4: 0x1ef36 - <unknown>
```
cc `@jethrogb` and `@workingjubilee`
Add Seek::seek_relative
The `BufReader` struct has a `seek_relative` method because its `Seek::seek` implementation involved dumping the internal buffer (https://github.com/rust-lang/rust/issues/31100).
Unfortunately, there isn't really a good way to take advantage of that method in generic code. This PR adds the same method to the main `Seek` trait with the straightforward default method, and an override for `BufReader` that calls its implementation.
_Also discussed in [this](https://internals.rust-lang.org/t/add-seek-seek-relative/19546) internals.rust-lang.org thread._
Add T: ?Sized to `RwLockReadGuard` and `RwLockWriteGuard`'s Debug impls.
For context, `MutexGuard` has `+ ?Sized` on its `Debug` impl, and all three have `+ ?Sized` on their `Display` impls.
It looks like the `?Sized` was just missed when the impls were added (the impl for `MutexGuard` was added in the same PR (https://github.com/rust-lang/rust/pull/38006) with support for `T: Debug + ?Sized`, and `RwLock*Guard`s did allow `T: ?Sized` types already); the `Display` impls were added later (https://github.com/rust-lang/rust/pull/42822) with support for `T: Debug + ?Sized` types.
I think this needs a T-libs-api FCP? I'm not sure if this also needs an ACP. If so I can make one.
These are changes to (stable) trait impls on stable types so will be insta-stable.
`@rustbot` label +T-libs-api
Remove asmjs
Fulfills [MCP 668](https://github.com/rust-lang/compiler-team/issues/668).
`asmjs-unknown-emscripten` does not work as-specified, and lacks essential upstream support for generating asm.js, so it should not exist at all.
Xous as an operating system is compiled with gcc-type personalities when
it comes to unwinding. This enables unwinding inside panics on Xous,
which enables Rust tests.
Signed-off-by: Sean Cross <sean@xobs.io>
Add `std:#️⃣:{DefaultHasher, RandomState}` exports (needs FCP)
This implements rust-lang/libs-team#267 to move the libstd hasher types to `std::hash` where they belong, instead of `std::collections::hash_map`.
<details><summary>The below no longer applies, but is kept for clarity.</summary>
This is a small refactor for #27242, which moves the definitions of `RandomState` and `DefaultHasher` into `std::hash`, but in a way that won't be noticed in the public API.
I've opened rust-lang/libs-team#267 as a formal ACP to move these directly into the root of `std::hash`, but for now, they're at least separated out from the collections code in a way that will make moving that around easier.
I decided to simply copy the rustdoc for `std::hash` from `core::hash` since I think it would be ideal for the two to diverge longer-term, especially if the ACP is accepted. However, I would be willing to factor them out into a common markdown document if that's preferred.
</details>
Removes the private type `std::sys::solid::net::FileDesc`, replacing its
only usage in `std::sys::solid::net::Socket` with `std::os::solid::io::
OwnedFd`.
The initial probe-for-empty-source by stack_buffer_copy only detected EOF
if the source was empty but not when it was merely small which lead to
additional calls to read() after Ok(0) had already been returned
in the stack copy routine
It now keeps track of initialized bytes to avoid reinitialization.
It also keeps track of read sizes to avoid initializing more bytes
than the reader needs. This is important when passing a huge vector to a
Read that only has a few bytes to offer and doesn't implement read_buf().
Time in UNIX system calls counts from the epoch, 1970-01-01. The timespec
struct used in various system calls represents this as a number of seconds and
a number of nanoseconds. Nanoseconds are required to be between 0 and
999_999_999, because the portion outside that range should be represented in
the seconds field; if nanoseconds were larger than 999_999_999, the seconds
field should go up instead.
Suppose you ask for the time 1969-12-31, what time is that? On UNIX systems
that support times before the epoch, that's seconds=-86400, one day before the
epoch. But now, suppose you ask for the time 1969-12-31 23:59:00.1. In other
words, a tenth of a second after one minute before the epoch. On most UNIX
systems, that's represented as seconds=-60, nanoseconds=100_000_000. The macOS
bug is that it returns seconds=-59, nanoseconds=-900_000_000.
While that's in some sense an accurate description of the time (59.9 seconds
before the epoch), that violates the invariant of the timespec data structure:
nanoseconds must be between 0 and 999999999. This causes this assertion in the
Rust standard library.
So, on macOS, if we get a Timespec value with seconds less than or equal to
zero, and nanoseconds between -999_999_999 and -1 (inclusive), we can add
1_000_000_000 to the nanoseconds and subtract 1 from the seconds, and then
convert. The resulting timespec value is still accepted by macOS, and when fed
back into the OS, produces the same results. (If you set a file's mtime with
that timestamp, then read it back, you get back the one with negative
nanoseconds again.)
Co-authored-by: Josh Triplett <josh@joshtriplett.org>
Increase the reach of panic_immediate_abort
I wanted to use/abuse this recently as part of another project, and I was surprised how many panic-related things were left in my binaries if I built a large crate with the feature enabled along with LTO. These changes get all the panic-related symbols that I could find out of my set of locally installed Rust utilities.
Create `windows/api.rs` for safer FFI
FFI is inherently unsafe. For memory safety we need to assert that some contract is being upheld on both sides of the FFI, though of course we can only ever check our side. In Rust, `unsafe` blocks are used to assert safety and `// SAFETY` comments describing why it is safe. Currently in sys/windows we have a lot of this unsafety spread all over the place, with variations on the same unsafe patterns repeated. And because of the repitition and frequency, we're a bit lax with the safety comments.
This PR aims to fix this and to make FFI safety more auditable by creating an `api` module with the goal of centralising and consolidating this unsafety. It contains thin wrappers around the Windows API that make most functions safe to call or, if that's not possible, then at least safer. Note that its goal is *only* to address safety. It does not stray far from the Windows API and intentionally does not attempt to make higher lever wrappers around, for example, file handles. This is better left to the existing modules. The windows/api.rs file has a top level comment to help future contributors understand the intent of the module and the design decisions made.
I chose two functions as a first tentative step towards the above goal:
- [`GetLastError`](https://learn.microsoft.com/en-us/windows/win32/api/errhandlingapi/nf-errhandlingapi-getlasterror) is trivially safe. There's no reason to wrap it in an `unsafe` block every time. So I simply created a safe `get_last_error` wrapper.
- [`SetFileInformationByHandle`](https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-setfileinformationbyhandle) is more complex. It essentially takes a generic type but over a C API which necessitates some amount of ceremony. Rather than implementing similar unsafe patterns in multiple places, I provide a safe `set_file_information_by_handle` that takes a Rusty generic type and handles converting that to the form required by the C FFI.
r? libs
Hide internal methods from documentation
The two methods here are perma-unstable and only made public for technical reasons. There is no reason to show them in documentation.
`@rustbot` label +A-docs
Rollup of 6 pull requests
Successful merges:
- #114998 (feat(docs): add cargo-pgo to PGO documentation 📝)
- #116868 (Tweak suggestion span for outer attr and point at item following invalid inner attr)
- #117240 (Fix documentation typo in std::iter::Iterator::collect_into)
- #117241 (Stash and cancel cycle errors for auto trait leakage in opaques)
- #117262 (Create a new ConstantKind variant (ZeroSized) for StableMIR)
- #117266 (replace transmute by raw pointer cast)
r? `@ghost`
`@rustbot` modify labels: rollup
These methods are the pre-stabilized API for obtaining peer credentials
from an `AF_UNIX` socket, part of the `unix_socket_ancillary_data` feature.
Their current behavior is to get/set one of the `SO_PASSCRED` (Linux),
`LOCAL_CREDS_PERSISTENT` (FreeBSD), or `LOCAL_CREDS` (NetBSD) socket
options. On other targets the `{set_}passcred()` methods do not exist.
There are two problems with this approach:
1. Having public methods only exist for certain targets isn't permitted
in a stable `std` API.
2. These options have generally similar purposes, but they are non-POSIX
and their details can differ in subtle and surprising ways (such as
whether they continue to be set after the next call to `recvmsg()`).
Splitting into OS-specific extension traits is the preferred solution to
both problems.
Validate `feature` and `since` values inside `#[stable(…)]`
Previously the string passed to `#[unstable(feature = "...")]` would be validated as an identifier, but not `#[stable(feature = "...")]`. In the standard library there were `stable` attributes containing the empty string, and kebab-case string, neither of which should be allowed.
Pre-existing validation of `unstable`:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![unstable(feature = "kebab-case", issue = "none")]
#[unstable(feature = "kebab-case", issue = "none")]
pub struct Struct;
```
```console
error[E0546]: 'feature' is not an identifier
--> src/lib.rs:5:1
|
5 | #![unstable(feature = "kebab-case", issue = "none")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
For an `unstable` attribute, the need for an identifier is obvious because the downstream code needs to write a `#![feature(...)]` attribute containing that identifier. `#![feature(kebab-case)]` is not valid syntax and `#![feature(kebab_case)]` would not work if that is not the name of the feature.
Having a valid identifier even in `stable` is less essential but still useful because it allows for informative diagnostic about the stabilization of a feature. Compare:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![stable(feature = "kebab-case", since = "1.0.0")]
#[stable(feature = "kebab-case", since = "1.0.0")]
pub struct Struct;
```
```rust
// src/main.rs
#![feature(kebab_case)]
use repro::Struct;
fn main() {}
```
```console
error[E0635]: unknown feature `kebab_case`
--> src/main.rs:3:12
|
3 | #![feature(kebab_case)]
| ^^^^^^^^^^
```
vs the situation if we correctly use `feature = "snake_case"` and `#![feature(snake_case)]`, as enforced by this PR:
```console
warning: the feature `snake_case` has been stable since 1.0.0 and no longer requires an attribute to enable
--> src/main.rs:3:12
|
3 | #![feature(snake_case)]
| ^^^^^^^^^^
|
= note: `#[warn(stable_features)]` on by default
```
Windows: Support sub-millisecond sleep
Use `CreateWaitableTimerExW` with `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`. Does not work before Windows 10, version 1803 so in that case we fallback to using `Sleep`.
I've created a `WaitableTimer` type so it can one day be adapted to also support waiting to an absolute time (which has been talked about). Note though that it currently returns `Err(())` because we can't do anything with the errors other than fallback to the old `Sleep`. Feel free to tell me to do errors properly. It just didn't seem worth constructing an `io::Error` if we're never going to surface it to the user. And it *should* all be infallible anyway unless the OS is too old to support it.
Closes#43376
Remove Apple RNG fallbacks and simplify implementation
Now that we have [higher Apple platform requirements](https://github.com/rust-lang/rust/pull/104385), the RNG code can be simplified a lot. Since `getentropy` still doesn't look to be usable outside macOS this implementation:
- Removes any macOS fallback paths and unconditionally links to `getentropy`
- Minimizes the implementation for everything else (iOS, watchOS, etc).
`CCRandomGenerateBytes` was added in iOS 8 which means that we can use it now. It and `SecRandomCopyBytes` have the exact same functionality, but the former has a simpler API and no longer requires libstd to link to `Security.framework` for one function. Its also available in all the other target's SDKs.
Why care about `getentropy` then though on macOS? Well, its still much more performant. Benchmarking shows it runs at ~2x the speed of `CCRandomGenerateBytes`, which makes sense since it directly pulls from the kernel vs going through its own generator etc.
Semi-related to a previous, but reverted, attempt at improving this logic in https://github.com/rust-lang/rust/pull/101011
time: use clock_gettime on macos
Replace `gettimeofday` with `clock_gettime(CLOCK_REALTIME)` on:
```
all(target_os = "macos", not(target_arch = "aarch64")),
target_os = "ios",
target_os = "watchos",
target_os = "tvos"
))]
```
`gettimeofday` was first used in
cc367edd95
which predated the introduction of `clock_gettime` support in macOS
10.12 Sierra which became the minimum supported version in
58bbca958d.
Replace `mach_{absolute_time,timebase_info}` with
`clock_gettime(CLOCK_REALTIME)` on:
```
all(target_os = "macos", not(target_arch = "aarch64")),
target_os = "ios",
target_os = "watchos",
target_os = "tvos"
))]
```
`mach_{absolute_time,timebase_info}` were first used in
cc367edd95
which predated the introduction of `clock_gettime` support in macOS
10.12 Sierra which became the minimum supported version in
58bbca958d.
Note that this change was made for aarch64 in
5008a317ce which predated 10.12 becoming
the minimum supported version. The discussion took place in
https://github.com/rust-lang/rust/issues/91417 and in particular
https://github.com/rust-lang/rust/issues/91417#issuecomment-992151582
and
https://github.com/rust-lang/rust/issues/91417#issuecomment-1033048064
are relevant.
Rollup of 6 pull requests
Successful merges:
- #107159 (rand use getrandom for freebsd (available since 12.x))
- #116859 (Make `ty::print::Printer` take `&mut self` instead of `self`)
- #117046 (return unfixed len if pat has reported error)
- #117070 (rustdoc: wrap Type with Box instead of Generics)
- #117074 (Remove smir from triage and add me to stablemir)
- #117086 (Update .mailmap to promote my livename)
r? `@ghost`
`@rustbot` modify labels: rollup
report `unused_import` for empty reexports even it is pub
Fixes#116032
An easy fix. r? `@petrochenkov`
(Discovered this issue while reviewing #115993.)
On Windows make `read_dir` error on the empty path
This makes Windows consistent with other platforms. Note that this should not be taken to imply any decision on #114149 has been taken. However it was felt that while there is a lack of libs-api consensus, we should be consistent across platforms in the meantime.
This is a change in behaviour for Windows so will also need an fcp before merging.
r? libs-api
Specialize `Bytes<R>::next` when `R` is a `BufReader`.
This reduces the runtime for a simple program using `Bytes::next` to iterate through a file from 220ms to 70ms on my Linux box.
r? `@the8472`
Make TCP connect handle EINTR correctly
According to the [POSIX](https://pubs.opengroup.org/onlinepubs/009695399/functions/connect.html) standard, if connect() is interrupted by a signal that is caught while blocked waiting to establish a connection, connect() shall fail and set errno to EINTR, but the connection request shall not be aborted, and the connection shall be established asynchronously. When the connection has been established asynchronously, select() and poll() shall indicate that the file descriptor for the socket is ready for writing.
The previous implementation differs from the recomendation: in a case of the EINTR we tried to reconnect in a loop and sometimes get EISCONN error (this problem was originally detected on MacOS).
1. More details about the problem in an [article](http://www.madore.org/~david/computers/connect-intr.html).
2. The original [issue](https://git.picodata.io/picodata/picodata/tarantool-module/-/issues/157).
Panic when the global allocator tries to register a TLS destructor
Using a `RefCell` avoids the undefined behaviour encountered in #116390 and reduces the amount of `unsafe` code in the codebase.
The bug report #27970 has existed for 8 years, the actual bug dates back
to Rust pre-1.0. I documented it since it's in the interest of the user
to be aware of it. The note can be removed once #27970 is fixed.
Updated libc and doc for Vita target
Doc changes:
- Updated Vita target readme. The recommended approach to build artifacts for the platform now is [cargo-vita](https://crates.io/crates/cargo-vita) which wraps all the convoluted steps previously described in a yaml for `cargo-make`
- Updated maintainer list for Vita target. (`@ZetaNumbers` `@pheki` please agree to be added to the list, `@amg98` please let us know if you're still planning on actively maintaining target support)
Code changes:
- ~Updated libc for rust-lang/libc#3284 and rust-lang/libc#3366~ (Already merged in #116527)
- In dupfd changed the flag same as for esp target, there is no CLOEXEC on Vita
- Enabled `new_pair` since we've implemented `socketpair` in Vita newlib
Inline `Bytes::next` and `Bytes::size_hint`.
This greatly increases its speed. On one small test program using `Bytes::next` to iterate over a large file, execution time dropped from ~330ms to ~220ms.
r? `@the8472`
impl Default for ExitCode
As suggested here
https://github.com/rust-lang/rust/pull/106425#issuecomment-1382952598
Needs FCP since this is an insta-stable impl.
Ideally we would have `impl From<ExitCode> for ExitStatus` and implement the default `ExitStatus` using that. That is sadly not so easy because of the various strange confusions about `ExitCode` (unix: exit status) vs `ExitStatus` (unix: wait status) in the not-really-unix platforms in `library//src/sys/unix/process`. I'll try to follow that up.
Implement sys::args for UEFI
- Uses `EFI_LOADED_IMAGE_PROTOCOL`, which is implemented for all loaded images.
Tested on qemu with OVMF
cc ``@nicholasbishop``
cc ``@dvdhrm``
Broaden the consequences of recursive TLS initialization
This PR updates the documentation of `LocalKey` to clearly disallow the behaviour described in [this comment](https://github.com/rust-lang/rust/issues/110897#issuecomment-1525738849). This allows using `OnceCell` for the lazy initialization of TLS variables, which panics on reentrant initialization instead of updating the value like TLS variables currently do.
``@rustbot`` label +T-libs-api
r? ``@m-ou-se``
error[E0711]: feature `process-exitcode-default` is declared stable since 1.74.0-beta.1, but was previously declared stable since 1.73.0
--> library/std/src/process.rs:1964:1
|
1964 | #[stable(feature = "process-exitcode-default", since = "CURRENT_RUSTC_VERSION")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Previously it failed on Windows if the file had the `FILE_ATTRIBUTE_HIDDEN` attribute set. This was inconsistent with `OpenOptions::new().write(true).truncate(true)` which can truncate an existing hidden file.
Make `try_exists` return `Ok(true)` for Windows Unix Sockets
This is a follow up to #109106 but for[ `fs::try_exists`](https://doc.rust-lang.org/std/fs/fn.try_exists.html), which doesn't need to get the metadata of a file (which can fail even if a file exists).
`fs::try_exists` currently fails on Windows if encountering a Unix Domain Socket (UDS). This PR fixes it by checking for an error code that's returned when there's a failure to use a reparse point.
## Reparse points
A reparse point is a way to invoke a filesystem filter on a file instead of the file being opened normally. This is used to implement symbolic links (by redirecting to a different path) but also to implement other types of special files such as Unix domain sockets. If the reparse point is not a link type then opening it with `CreateFileW` may fail with `ERROR_CANT_ACCESS_FILE` because the filesystem filter does not implement that operation. This differs from resolving links which may fail with errors such as `ERROR_FILE_NOT_FOUND` or `ERROR_CANT_RESOLVE_FILENAME`.
So `ERROR_CANT_ACCESS_FILE` means that the file exists but that we can't open it normally. Still, the file does exist on the filesystem so `try_exists` should report that as `Ok(true)`.
r? libs
Fix exit status / wait status on non-Unix cfg(unix) platforms
Fixes#114593
Needs FCP due to behavioural changes (NB only on non-Unix `#[cfg(unix)]` platforms).
Also, I think this is likely to break in CI. I have not been yet able to compile the new bits of `process_unsupported.rs`, although I have compiled the new module. I'd like some help from people familiar with eg emscripten and fuchsia (which are going to be affected, I think).
According to the POSIX standard, if connect() is interrupted by a
signal that is caught while blocked waiting to establish a connection,
connect() shall fail and set errno to EINTR, but the connection
request shall not be aborted, and the connection shall be established
asynchronously.
If asynchronous connection was successfully established after EINTR
and before the next connection attempt, OS returns EISCONN that was
handled as an error before. This behavior is fixed now and we handle
it as success.
The problem affects MacOS users: Linux doesn't return EISCONN in this
case, Windows connect() can not be interrupted without an old-fashoin
WSACancelBlockingCall function that is not used in the library.
So current solution gives connect() as OS specific implementation.
`fs::try_exists` currently fails on Windows if encountering a Unix Domain Socket (UDS). Fix this by checking for an error code that's returned when there's a failure to use a reparse point.
A reparse point is a way to invoke a filesystem filter on a file instead of the file being opened normally. This is used to implement symbolic links (by redirecting to a different path) but also to implement other types of special files such as Unix domain sockets. If the reparse point is not a link type then opening it with `CreateFileW` may fail with `ERROR_CANT_ACCESS_FILE` because the filesystem filter does not implement that operation. This differs from resolving links which may fail with errors such as `ERROR_FILE_NOT_FOUND` or `ERROR_CANT_RESOLVE_FILENAME`.
So `ERROR_CANT_ACCESS_FILE` means that the file exists but that we can't open it normally. Still, the file does exist so `try_exists` should report that as `Ok(true)`.
Remove unnecessary tmp variable in default_read_exact
This `tmp` variable has existed since the original implementation (added in ff81920f03), but it's not necessary (maybe non-lexical lifetimes helped?).
It's common to read std source code to understand how things actually work, and this tripped me up on my first read.
* Entries in the callsite table now use a dedicated function for reading an offset rather than a pointer
* `read_encoded_pointer` uses that new function for reading offsets when the "application" part of the encoding indicates an offset (relative to some pointer)
* It now errors out on nonsensical "application" and "value encoding" combinations
Inspired by @eddyb's comment on zulip about this:
<https://rust-lang.zulipchat.com/#narrow/stream/136281-t-opsem/topic/strict.20provenance.20in.20dwarf.3A.3Aeh/near/276197290>
Rollup of 4 pull requests
Successful merges:
- #116277 (dont call mir.post_mono_checks in codegen)
- #116400 (Detect missing `=>` after match guard during parsing)
- #116458 (Properly export function defined in test which uses global_asm!())
- #116500 (Add tvOS to target_os for register_dtor)
r? `@ghost`
`@rustbot` modify labels: rollup
Rollup of 6 pull requests
Successful merges:
- #115454 (Clarify example in docs of str::char_slice)
- #115522 (Clarify ManuallyDrop bit validity)
- #115588 (Fix a comment in std::iter::successors)
- #116198 (Add more diagnostic items for clippy)
- #116329 (update some comments around swap())
- #116475 (rustdoc-search: fix bug with multi-item impl trait)
r? `@ghost`
`@rustbot` modify labels: rollup
`waitqueue` clarifications for SGX platform
The documentation of `waitqueue` functions on the `x86_64-fortanix-unknown-sgx` platform is incorrect at some places and on others missing. This PR improves upon this.
cc: `@jethrogb`
Use `CreateWaitableTimerExW` with `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`. Does not work before Windows 10, version 1803 so in that case we fallback to using `Sleep`.
Works around #115199 by temporarily disabling CFI for core and std CFI
violations to allow the user rebuild and use both core and std with CFI
enabled using the Cargo build-std feature.
Replace 'mutex' with 'lock' in RwLock documentation
When copying the documentation for `clear_poison` from Mutex, not every occurence of 'mutex' was replaced with 'lock'.
Improve UdpSocket documentation
I tried working with `UdpSocket` and ran into `EINVAL` errors with no clear indication of what causes the error. Also, it was uncharacteristically hard to figure this module out, compared to other Rust `std` modules.
1. `send` and `send_to` return a `usize` This one is just clarity. Usually, returned `usize`s indicate that the buffer might have only been sent partially. This is not the case with UDP. Since that `usize` must always be `buffer.len()`, I have documented that.
2. `bind` limits `connect` and `send_to` When you bind to a limited address space like localhost, you can only `connect` to addresses in that same address space. Error kind: `AddrNotAvailable`.
3. `connect`ing to localhost locks you to localhost On Linux, if you first `connect` to localhost, subsequent `connect`s to
non-localhost addresses fail. Error kind: `InvalidInput`.
For debugging the third one, it was really hard to find someone else who already had that problem. I only managed to find this thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg159519.html
Add missing #[inline] on AsFd impl for sys::unix::fs::File
This operation should be extremely cheap, at most the `mov` of the underlying file descriptor, but due to this missing `#[inline]` it is currently a function call.
Stdio support for UEFI
- Uses Simple Text Output Protocol and Simple Text Input Protocol
- Reading is done one character at a time
- Writing is done with max 4096 characters
# Quirks
## Output Newline
- UEFI uses CRLF for newline. So when running the application in UEFI shell (qemu VGA), the output of `println` looks weird.
- However, since the UEFI shell supports piping output, I am unsure if doing any output post-processing is a good idea. UEFI shell `cat` command seems to work fine with just LF.
## Input Newline
- `Stdin.read_line()` method is broken in UEFI shell. Pressing enter seems to be read as CR, which means LF is never encountered.
- Works fine with input redirection from file.
CC `@dvdhrm`
- Uses Simple Text Output Protocol and Simple Text Input Protocol
- Reading is done one character at a time
- Writing is done with max 4096 characters
Signed-off-by: Ayush Singh <ayushdevel1325@gmail.com>
Document that Instant may or may not include system-suspend time
Since people are still occasionally surprised by this let's make it more explicit. This doesn't add any new guarantees, only documents the status quo.
Related issues: #87906#79462
This operation should be extremely cheap, at most the mov of the underlying
file descriptor, but due to this missing #[inline] it is currently a function
call.
Replace `gettimeofday` with `clock_gettime(CLOCK_REALTIME)` on:
```
all(target_os = "macos", not(target_arch = "aarch64")),
target_os = "ios",
target_os = "watchos",
target_os = "tvos"
))]
```
`gettimeofday` was first used in
cc367edd95
which predated the introduction of `clock_gettime` support in macOS
10.12 Sierra which became the minimum supported version in
58bbca958d.
Update windows ffi bindings
Bump `windows-bindgen` to version 0.51.1. This brings with it some changes to the generated FFI bindings, but little that affects the code.
One change that does have more of an impact is `SOCKET` being `usize` instead of either `u64` or `u32` (as is used in std's public `SOCKET` type). However, it's now easy enough to abstract over that difference.
Finally I added a few new bindings that are likely to be used in pending PRs, mostly to make sure they're ok with the new metadata.
r? libs
Convert `Into<ExitStatus> for ExitStatusError` to `From<ExitStatusError> for ExitStatus` in `std::process`
Implementing suggestion from https://github.com/rust-lang/rust/issues/84908#issuecomment-912352902:
> I believe the impl on ExitStatusError should be
>
> ```rust
> impl From<ExitStatusError> for ExitStatus
> ```
>
> rather than
>
> ```rust
> impl Into<ExitStatus> for ExitStatusError
> ```
>
> (there is generally never anything implemented as `Into` first, because implementing `From` reflexively provides `Into`)
Implement From<OwnedFd/Handle> for ChildStdin/out/err object
## Summary
Comments in `library/std/src/process.rs` ( ab08639e59 ) indicates that `ChildStdin`, `ChildStdout`, `ChildStderr` implements some traits that are not actually implemented: `FromRawFd`, `FromRawHandle`, and the `From<OwnedFd>/From<OwnedHandle>` from the io_safety feature.
In this PR I implement `FromRawHandle` and `FromRawFd` for those 3 objects.
## Usecase
I have a usecase where those implementations are basically needed. I want to customize
in the `Command::spawn` API how the pipes for the parent/child communications are created (mainly to strengthen the security attributes on them). I can properly setup the pipes,
and the "child" handles can be provided to `Child::spawn` easily using `Stdio::from_raw_handle`. However, there is no way to generate the `ChildStd*` objects from the raw handle of the created name pipe, which would be very useful to still expose the same API
than in other OS (basically a `spawn(...) -> (Child, ChildStdin, ChildStdout, ChildSterr)`, where on windows this is customized), and to for example use `tokio::ChildStdin::from_std` afterwards.
## Questions
* Are those impls OK to add? I have searched to see if those impls were missing on purpose, or if it was just never implemented because never needed. I haven't found any indication on why they couldn't be added, although the user clearly has to be very careful that the handle provided makes sense (i think, mainly that it is in overlapped mode for windows).
* If this change is ok, adding the impls for the io_safety feature would probably be best, or should it be done in another PR?
* I just copy-pasted the `#[stable(...)]` attributes, but the `since` value has to be updated, I'm not sure to which value.
fix OS-specific I/O safety docs since the io_safety feature is stable
Looks like this text was forgotten to be updated when `io_safety` got stabilized: it still says "once the io_safety feature is stable".
Also adjust the wording a bit for how these docs relate to the general concept of I/O safety.
Add Minimal Std implementation for UEFI
# Implemented modules:
1. alloc
2. os_str
3. env
4. math
# Related Links
Tracking Issue: https://github.com/rust-lang/rust/issues/100499
API Change Proposal: https://github.com/rust-lang/libs-team/issues/87
# Additional Information
This was originally part of https://github.com/rust-lang/rust/pull/100316. Since that PR was becoming too unwieldy and cluttered, and with suggestion from `@dvdhrm,` I have extracted a minimal std implementation to this PR.
The example in `src/doc/rustc/src/platform-support/unknown-uefi.md` has been tested for `x86_64-unknown-uefi` and `i686-unknown-uefi` in OVMF. It would be great if someone more familiar with AARCH64 can help with testing for that target.
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
Add the `cfg_match!` macro
# Movitation
Adds a match-like version of the `cfg_if` crate without a RFC [for the same reasons that caused `matches!` to be included in the standard library](https://github.com/rust-lang/rust/pull/65479).
* General-purpose (not domain-specific)
* Simple (the implementation is short) and useful (things can become difficult with several `cfg`s)
* Very popular [on crates.io ](https://crates.io/crates/cfg-if) (currently 3th in all-time downloads)
* The two previous points combined make it number three in [left-pad index](https://twitter.com/bascule/status/1184523027888988160) score
```rust
match_cfg! {
cfg(unix) => {
fn foo() { /* unix specific functionality */ }
}
cfg(target_pointer_width = "32") => {
fn foo() { /* non-unix, 32-bit functionality */ }
}
_ => {
fn foo() { /* fallback implementation */ }
}
}
```
# Considerations
A match-like syntax feels more natural in the sense that each macro fragment resembles an arm but I personally don't mind switching to any other desired syntax.
The lack of `#[ ... ]` is intended to reduce typing, nevertheless, the same reasoning described above can also be applied to this aspect.
Since blocks are intended to only contain items, anything but `cfg` is not expected to be supported at the current or future time.
~~Credits goes to `@gnzlbg` because most of the code was shamelessly copied from https://github.com/gnzlbg/match_cfg.~~
Credits goes to `@alexcrichton` because most of the code was shamelessly copied from https://github.com/rust-lang/cfg-if.
Raise minimum supported Apple OS versions
This implements the proposal to raise the minimum supported Apple OS versions as laid out in the now-completed MCP (https://github.com/rust-lang/compiler-team/issues/556).
As of this PR, rustc and the stdlib now support these versions as the baseline:
- macOS: 10.12 Sierra
- iOS: 10
- tvOS: 10
- watchOS: 5 (Unchanged)
In addition to everything this breaks indirectly, these changes also erase the `armv7-apple-ios` target (currently tier 3) because the oldest supported iOS device now uses ARMv7s. Not sure what the policy around tier3 target removal is but shimming it is not an option due to the linker refusing.
[Per comment](https://github.com/rust-lang/compiler-team/issues/556#issuecomment-1297175073), this requires a FCP to merge. cc `@wesleywiser.`
- Some comment fixes.
- Make some functions unsafe.
- Make helpers module private.
- Rebase on master
- Update r-efi to v4.2.0
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
- Make BootServices unavailable if ExitBootServices event is signaled.
- Use thread locals for SystemTable and ImageHandle
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
Command: also print removed env vars
There is no real shell syntax for unsetting an env var so easily, so we have to make one up. But we already do that for showing the 'program' name so I hope that's okay here, too. No strong opinion on what that should look like, I went with `unset(VAR_NAME)` for now.
Rename BoxMeUp to PanicPayload.
"BoxMeUp" is not very clear. Let's rename that to a description of what it actually represents: a panic payload.
This PR also renames the structs that implement this trait to have more descriptive names.
Part of https://github.com/rust-lang/rust/issues/116005
r? `@oli-obk`
Simplify/Optimize FileEncoder
FileEncoder is basically a BufWriter except that it exposes access to the not-written-to-yet region of the buffer so that some users can write directly to the buffer. This strategy is awesome because it lets us avoid calling memcpy for small copies, but the previous strategy was based on the writer accessing a `&mut [MaybeUninit<u8>; N]` and returning a `&[u8]` which is an API which currently mandates the use of unsafe code, making that interface in general not that appealing.
So this PR cleans up the FileEncoder implementation and builds on that general idea of direct buffer access in order to prevent `memcpy` calls in a few key places when encoding the dep graph and rmeta tables. The interface used here is now 100% safe, but with the caveat that internally we need to avoid trusting the number of bytes that the provided function claims to have written.
The original primary objective of this PR was to clean up the FileEncoder implementation so that the fix for the following issues would be easy to implement. The fix for these issues is to correctly update self.buffered even when writes fail, which I think it's easy to verify manually is now done, because all the FileEncoder methods are small.
Fixes https://github.com/rust-lang/rust/issues/115298
Fixes https://github.com/rust-lang/rust/issues/114671
Fixes https://github.com/rust-lang/rust/issues/114045
Fixes https://github.com/rust-lang/rust/issues/108100
Fixes https://github.com/rust-lang/rust/issues/106787
Refactor `thread_info` to remove the `RefCell`
`thread_info` currently uses `RefCell`-based initialization. Refactor this to use `OnceCell` instead which is more performant and better suits the needs of one-time initialization.
This is nobody's bottleneck but OnceCell checks are a single `cmp` vs. `RefCell<Option>` needing runtime logic
Don't modify libstd to dump rustc ICEs
Do a much simpler thing and just dump a `std::backtrace::Backtrace` to file.
r? `@estebank` `@oli-obk`
Fixes#115610
Add initial libstd support for Xous
This patchset adds some minimal support to the tier-3 target `riscv32imac-unknown-xous-elf`. The following features are supported:
* alloc
* thread creation and joining
* thread sleeping
* thread_local
* panic_abort
* mutex
* condvar
* stdout
Additionally, internal support for the various Xous primitives surrounding IPC have been added as part of the Xous FFI. These may be exposed as part of `std::os::xous::ffi` in the future, however for now they are not public.
This represents the minimum viable product. A future patchset will add support for networking and filesystem support.
`thread_info` currently uses `RefCell`-based initialization. Refactor
this to use `OnceCell` instead which is more performant and better suits
the needs of one-time initialization.
Allow redirecting subprocess stdout to our stderr etc. (redux)
This is the code from #88561, tidied up, including review suggestions, and with the for-testing-only CI commit removed. FCP for the API completed in #88561.
I have made a new MR to facilitate review. The discussion there is very cluttered and the branch is full of changes (in many cases as a result of changes to other Rust stdlib APIs since then). Assuming this MR is approvedl we should close that one.
### Reviewer doing a de novo review
Just code review these four commits.. FCP discussion starts here: https://github.com/rust-lang/rust/pull/88561#issuecomment-1640527595
Portability tests: you can see that this branch works on Windows too by looking at the CI results in #88561, which has the same code changes as this branch but with an additional "DO NOT MERGE" commit to make the Windows tests run.
### Reviewer doing an incremental review from some version of #88561
Review the new commits since your last review. I haven't force pushed the branch there.
git diff the two branches (eg `git diff 176886197d6..0842b69c219`). You'll see that the only difference is in gitlab CI files. You can also see that *this* MR doesn't touch those files.
This implementation is wrong. Like the impl for From<File>, it is
forced to panic because process::Stdio in unsupported/process.rs
doesn't have a suitable variant.
The root cause of the problem is that process::Stdio in
unsupported/process.rs has any information in it at all.
I'm pretty sure that it should just be a unit struct. However,
making that build on all platforms is going to be a lot of work,
iterating through CI and/or wrestling Docker.
I don't think this extra panic is making things significantly worse.
For now I have added some TODOs.
Move RawOsError defination to sys
This was originally a part of https://github.com/rust-lang/rust/pull/105861, but I feel it should be its own PR since the raw os error is still unstable.
Use std::io::Error::is_interrupted everywhere
In https://github.com/rust-lang/rust/pull/115228 I introduced this helper and started using it, this PR uses it to replace all applicable uses of `std::io::Error::kind`. The justification is the same; for whatever reason LLVM totally flops optimizing `Error::kind` so it's nice to use it less.
FYI ``@mkroening`` I swear the hermit changes look good, but I was so sure about the previous PR.
Also stabilizes saturating_int_assign_impl, gh-92354.
And also make pub fns const where the underlying saturating_*
fns became const in the meantime since the Saturating type was
created.
kmc-solid: Fix `is_interrupted`
Follow-up to #115228. Fixes a build error in [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets.
```
error[E0603]: function `is_interrupted` is private
--> library\std\src\sys\solid\mod.rs:77:12
|
77 | error::is_interrupted(code)
| ^^^^^^^^^^^^^^ private function
|
note: the function `is_interrupted` is defined here
--> library\std\src\sys\solid\error.rs:35:1
|
35 | fn is_interrupted(er: abi::ER) -> bool {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
docs: improve std::fs::read doc
#### What does this PR do
1. Rephrase a confusing sentence in the document of `std::fs::read()`
-----
Closes#114432
cc `@Dexus0` `@saethlin`
Document that SystemTime does not count leap seconds
Fixes#77994
This may not be entirely uncontroversial. I know that `@Ekleog` is going to disagree. However, in support of this docs change:
This documents the current behaviour. The alternative would be to plan to *change* the behaviour.
There are many programs which need to get a POSIX time (a `time_t`). Right now, `duration_since(UNIX_EPOCH)` is the only facility in std that does that. So, that is what programs use. Changing the behaviour would break[1] all of those programs. We would need to define a new API that can be used to get a POSIX time, and get everyone to use it. This seems highly unpalatable.
And, even if we wanted to do that, time with leap seconds is a lot less easy to work with. We would need to arrange to have a leap seconds table available to `std` somehow, and make sure that it was kept up to date. Currently we don't offer to do that for timezone data, which has similar needs. There are other complications. So it seems it would be awkwarrd to *implement* a facility that provides time including leap seconds, and the resulting value would be hard for applications to work with.
Therefore, I think it's clear that we don't want to plan to ever change `SystemTime`. We should plan to keep it the way it is. Providing TAI (for example) should be left to external crates, or additional APIs we may add in the future.
For more discussion see #77994 and in particular `@fanf2's` https://github.com/rust-lang/rust/issues/77994#issuecomment-1409448174
[1] Of course, by "break" we really only mean *future* breakage in the case where there is, in fact, ever another leap second. There may well not be: they are in the process of being abolished (although this is of course being contested). But if we decide that `SystemTime::now().duraton_since(UNIX_EPOCH)` counts leap seconds, it would start to return `Durations`s that are 27s different to the current answers. That's clearly unacceptable. And we can hardly change `UNIX_EPOCH` by 27s.
wasi: round up the size for `aligned_alloc`
C11 `aligned_alloc` requires that the size be a multiple of the
alignment. This is enforced in the wasi-libc emmalloc implementation,
which always returns NULL if the size is not a multiple.
(The default `MALLOC_IMPL=dlmalloc` does not currently check this.)
Correct and expand documentation of `handle_alloc_error` and `set_alloc_error_hook`.
The primary goal of this change is to remove the false claim that `handle_alloc_error` always aborts; instead, code should be prepared for `handle_alloc_error` to possibly unwind, and be sound under that condition.
I saw other opportunities for improvement, so I have added all the following information:
* `handle_alloc_error` may panic instead of aborting. (Fixes#114898)
* What happens if a hook returns rather than diverging.
* A hook may panic. (This was already demonstrated in an example, but not stated in prose.)
* A hook must be sound to call — it cannot assume that it is only called by the runtime, since its function pointer can be retrieved by safe code.
I've checked these statements against the source code of `alloc` and `std`, but there may be nuances I haven't caught, so a careful review is welcome.
C11 `aligned_alloc` requires that the size be a multiple of the
alignment. This is enforced in the wasi-libc emmalloc implementation,
which always returns NULL if the size is not a multiple.
(The default `MALLOC_IMPL=dlmalloc` does not currently check this.)
Add a new helper to avoid calling io::Error::kind
On `cfg(unix)`, `Error::kind` emits an enormous jump table that LLVM seems unable to optimize out. I don't really understand why, but see for yourself: https://godbolt.org/z/17hY496KG
This change lets us check for `ErrorKind::Interrupted` without going through a big match. I've checked the codegen locally, and it has the desired effect on the codegen for `BufReader::read_exact`.
This implements the ability to add arbitrary attributes to a command on Windows targets using a new `raw_attribute` method on the [`CommandExt`](https://doc.rust-lang.org/stable/std/os/windows/process/trait.CommandExt.html) trait. Setting these attributes provides extended configuration options for Windows processes.
Co-authored-by: Tyler Ruckinger <t.ruckinger@gmail.com>
kmc-solid: Import `std::sync::PoisonError` in `std::sys::solid::os`
Follow-up to #114968. Fixes a missing import in [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets.
```
error[E0433]: failed to resolve: use of undeclared type `PoisonError`
C:\Users\xxxxx\.rustup\toolchains\nightly-2023-08-23-x86_64-pc-windows-gnu\lib\rustlib\src\rust\library\std\src\sys\solid\os.rs(85,36)
|
85 | ENV_LOCK.read().unwrap_or_else(PoisonError::into_inner)
| ^^^^^^^^^^^ use of undeclared type `PoisonError`
|
```
This is a pretty basic test but should spot any other platforms which
are `#[cfg(unix)]` but not Unix and where the wait status
representation is wrong. (And any actual Unix platforms where it's
not as expected, but I don't think they exist.)
I tried working with `UdpSocket` and ran into `EINVAL` errors with no
clear indication of what causes the error. Also, it was uncharacteristically
hard to figure this module out, compared to other Rust `std` modules.
1. `send` and `send_to` return a `usize`
This one is just clarity. Usually, returned `usize`s indicate that the
buffer might have only been sent partially. This is not the case with
UDP. Since that `usize` must always be `buffer.len()`, I have documented
that.
2. `bind` limits `connect` and `send_to`
When you bind to a limited address space like localhost, you can only
`connect` to addresses in that same address space. Error kind:
`AddrNotAvailable`.
3. `connect`ing to localhost locks you to localhost
On Linux, if you first `connect` to localhost, subsequent `connect`s to
non-localhost addresses fail. Error kind: `InvalidInput`.
Co-authored-by: Jubilee <46493976+workingjubilee@users.noreply.github.com>
Xous passes slice pointers around in order to manipulate memory.
This is feature-gated behind `slice_ptr_len`. Xous is currently
the only target to use this feature, so gate it behind an OS flag.
Signed-off-by: Sean Cross <sean@xobs.io>
Add an implementation of thread local storage. This uses a container
that is pointed to by the otherwise-unsed `$tp` register. This container
is allocated on-demand, so threads that use no TLS will not allocate
this extra memory.
Signed-off-by: Sean Cross <sean@xobs.io>
Add support for determining the current time. This connects to the
ticktimer server in order to get the system uptime.
Signed-off-by: Sean Cross <sean@xobs.io>
Add support for stdout. This enables basic console printing via
`println!()`. Output is written to the log server.
Signed-off-by: Sean Cross <sean@xobs.io>
Xous has a concept of `services` that provide various features.
Processes may connect to these services by name or by address. Most
services require a name server in order to connect.
Add a file with the most common services, and provide a way to connect
to a service by querying the name server.
Signed-off-by: Sean Cross <sean@xobs.io>
Basic alloc support on Xous is supported by the `dlmalloc` crate. This
necessitates bumping the dlmalloc version to 0.2.4.
Signed-off-by: Sean Cross <sean@xobs.io>
Add the basics to get the operating system running, including how to
exit the operating system.
Since Xous has no libc, there is no default entrypoint. Add a `_start`
entrypoint to the system-specific os module.
Signed-off-by: Sean Cross <sean@xobs.io>
Xous has no C FFI. Instead, all FFI is done via syscalls that are
specified in Rust. Add these FFI calls to libstd, as well as some of the
currently-supported syscalls.
This enables Rust programs to interact with the Xous operating system
while avoiding adding an extra dependency to libstd.
Signed-off-by: Sean Cross <sean@xobs.io>
Fix UB in `std::sys::os::getenv()`
Fixes#114949.
Reduced the loops to 1k iterations (100k was taking way too long), Miri no longer shows any UB.
`@rustbot` label +A-process +C-bug +I-unsound +O-unix
rustdoc: Add lint `redundant_explicit_links`
Closes#87799.
- Lint warns by default
- Reworks link parser to cache original link's display text
r? `@jyn514`
Usage zero as language id for `FormatMessageW()`
This switches the language selection from using system language (note that this might be different than application language, typically stored as thread ui language) to use `FormatMessageW` default search strategy, which is `neutral` first, then `thread ui lang`, then `user language`, then `system language`, then `English`. (See https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-formatmessagew)
This allows the Rust program to take more control of `std::io::Error`'s message field, by setting up thread ui language themselves before hand (which many programs already do).
Increase clarity about Hash - Eq consistency in HashMap and HashSet docs
As discussed [here](https://users.rust-lang.org/t/what-hapens-if-hash-and-partialeq-dont-match-when-using-hashmap/98052/13) the description of logic errors in `HashMap` and `HashSet` does not explicitly apply to
```text
k1 == k2 -> hash(k1) == hash(k2)
```
but this is likely what is intended.
This PR is a small doc change to correct this.
r? rust-lang/libs
Add the following facts:
* `handle_alloc_error` may panic instead of aborting.
* What happens if a hook returns rather than diverging.
* A hook may panic. (This was already demonstrated in an example,
but not stated in prose.)
* A hook must be sound to call — it cannot assume that it is only
called by the runtime, since its function pointer can be retrieved by
safe code.
Add `modulo` and `mod` as doc aliases for `rem_euclid`.
When I was learning Rust I looked for “a modulo function” and couldn’t find one, so thought I had to write my own; it wasn't at all obvious that a function with “rem” in the name was the function I wanted. Hopefully this will save the next learner from that.
However, it does have the disadvantage that the top results in rustdoc for “mod” are now these aliases instead of the Rust keyword, which probably isn't ideal.
Add doc aliases for trigonometry and other f32,f64 methods.
These are common alternate names, usually a less-abbreviated form, for the operation; e.g. `arctan` instead of `atan`. Prompted by <https://users.rust-lang.org/t/64-bit-trigonometry/98599>
When I was learning Rust I looked for “a modulo function” and couldn’t
find one, so thought I had to write my own; it wasn't at all obvious
that a function with “rem” in the name was the function I wanted.
Hopefully this will save the next learner from that.
However, it does have the disadvantage that the top results in rustdoc
for “mod” are now these aliases instead of the Rust keyword, which
probably isn't ideal.
Synchronize with all calls to `unpark` in id-based thread parker
[The documentation for `thread::park`](https://doc.rust-lang.org/nightly/std/thread/fn.park.html#memory-ordering) guarantees that "park synchronizes-with all prior unpark operations". In the id-based thread parking implementation, this is not implemented correctly, as the state variable is reset with a simple store, so there will not be a *synchronizes-with* edge if an `unpark` happens just before the reset. This PR corrects this, replacing the load-check-reset sequence with a single `compare_exchange`.
Partially revert #107200
`Ok(0)` is indeed something the caller may interpret as an error, but
that's the *correct* thing to return if the writer can't accept any more
bytes.
Improve docs for impl Default for ExitStatus
This addresses a review comment in #106425 (which is on the way to being merged I think).
Some of the other followup work is more complicated so I'm going to do individual MRs.
~~Note this branch is on top of #106425~~
std: add some missing repr(transparent)
For some types we don't want to stably guarantee this, so hide the `repr` from rustdoc. This nice approach was suggested by `@thomcc.`
add a csky-unknown-linux-gnuabiv2 target
This is the rustc side changes to support csky based Linux target(`csky-unknown-linux-gnuabiv2`).
Tier 3 policy:
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
I pledge to do my best maintaining it.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
This `csky` section is the arch name and the `unknown-linux` section is the same as other linux target, and `gnuabiv2` is from the cross-compile toolchain of `gcc`
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
I think the explanation in platform support doc is enough to make this aspect clear.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
It's using open source tools only.
> The target must not introduce license incompatibilities.
No new license
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
Understood.
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
There are no new dependencies/features required.
> Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
As previously said it's using open source tools only.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
There are no such terms present/
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
I'm not the reviewer here.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
I'm not the reviewer here.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
It supports for std
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
I have added the documentation, and I think it's clear.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Understood.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
I believe I didn't break any other target.
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
I think there are no such problems in this PR.
* remove `impl Provider for Error`
* rename `Demand` to `Request`
* update docstrings to focus on the conceptual API provided by `Request`
* move `core::any::{request_ref, request_value}` functions into `core::error`
* move `core::any::tag`, `core::any::Request`, an `core::any::TaggedOption` into `core::error`
* replace `provide_any` feature name w/ `error_generic_member_access`
* move `core::error::request_{ref,value} tests into core::tests::error module
* update unit and doc tests
reduce deps for windows-msvc targets for backtrace
(eventually) mirrors https://github.com/rust-lang/backtrace-rs/pull/543
Some dependencies of backtrace don't used on windows-msvc targets, so exclude them:
miniz_oxide (+ adler)
addr2line (+ gimli)
object (+ memchr)
This saves about 30kb of std.dll + 17.5mb of rlibs
[library/std] Replace condv while loop with `cvar.wait_while`.
`wait_while` takes care of spurious wake-ups in centralized place, reducing chances for mistakes and potential future optimizations (who knows, maybe in future there will be no spurious wake-ups? :)
Inline trivial (noop) flush calls
At work I noticed that `writer.flush()?` didn't get optimized away in cases where the flush is obviously a no-op, which I had expected (well, desired).
I went through and added `#[inline]` to a bunch of cases that were obviously noops, or delegated to ones that were obviously noops. I omitted platforms I don't have access to (some tier3). I didn't do this very scientifically, in cases where it was non-obvious I left `#[inline]` off.
Rollup of 6 pull requests
Successful merges:
- #113939 (open pidfd in child process and send to the parent via SOCK_SEQPACKET+CMSG)
- #114548 (Migrate a trait selection error to use diagnostic translation)
- #114606 (fix: not insert missing lifetime for `ConstParamTy`)
- #114634 (Mention riscv64-linux-android support in Android documentation)
- #114638 (Remove old RPITIT tests (revisions were removed))
- #114641 (Rename copying `ascii::Char` methods from `as_` to `to_`)
r? `@ghost`
`@rustbot` modify labels: rollup
open pidfd in child process and send to the parent via SOCK_SEQPACKET+CMSG
This avoids using `clone3` when a pidfd is requested while still getting it in a 100% race-free manner by passing it up from the child process.
This should solve most concerns in #82971
Make ExitStatus implement Default
And, necessarily, make it inhabited even on platforms without processes.
I noticed while preparing https://github.com/rust-lang/rfcs/pull/3362 that there was no way for anyone to construct an `ExitStatus`.
This would be insta-stable so needs an FCP.
unix/kernel_copy.rs: copy_file_range_candidate allows empty output files
This is for https://github.com/rust-lang/rust/issues/114341
The `meta.len() > 0` condition here is intended for inputs only, ie. when input is in the `/proc` filesystem as documented.
That inaccurately included empty output files which are then shunted to the sendfile() routine leading to higher than nescessary IO util in some cases, specifically with CoW filesystems like btrfs.
Simply, determine what is input or output given the passed boolean.
This is for https://github.com/rust-lang/rust/issues/114341
The `meta.len() > 0` condition here is intended for inputs only,
ie. when input is in the `/proc` filesystem as documented.
That inaccurately included empty output files which are then shunted to
the sendfile() routine leading to higher than nescessary IO util in some
cases, specifically with CoW filesystems like btrfs.
Further, `NoneObtained` is not relevant in this context, so remove it.
Simply, determine what is input or output given the passed enum Unit.
It lints against features that are inteded to be internal to the
compiler and standard library. Implements MCP #596.
We allow `internal_features` in the standard library and compiler as those
use many features and this _is_ the standard library from the "internal to the compiler and
standard library" after all.
Marking some features as internal wasn't exactly the most scientific approach, I just marked some
mostly obvious features. While there is a categorization in the macro,
it's not very well upheld (should probably be fixed in another PR).
We always pass `-Ainternal_features` in the testsuite
About 400 UI tests and several other tests use internal features.
Instead of throwing the attribute on each one, just always allow them.
There's nothing wrong with testing internal features^^
The extra `\0` in this commit is needed because the assertion on line 49 will fail otherwise (as `skip_until` stops reading on EOF and therefore does not read a trailing `\0`, returning 6 read bytes rather than the expected 7)
`wait_while` takes care of spurious wake-ups in centralized place,
reducing chances for mistakes and potential future optimizations
(who knows, maybe in future there will be no spurious wake-ups? :)
WASI threads, implementation of wasm32-wasi-preview1-threads target
This PR adds a target proposed in https://github.com/rust-lang/compiler-team/issues/574 by `@abrown` and implementation of `std:🧵:spawn` for the target `wasm32-wasi-preview1-threads`
### Tier 3 Target Policy
As tier 3 targets, the new targets are required to adhere to [the tier 3 target policy](https://doc.rust-lang.org/nightly/rustc/target-tier-policy.html#tier-3-target-policy) requirements. This section quotes each requirement in entirety and describes how they are met.
> - A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
See [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/pull/112922/files#diff-a48ee9d94f13e12be24eadd08eb47b479c153c340eeea4ef22276d876dfd4f3e).
> - Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
> - Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
If possible, use only letters, numbers, dashes and underscores for the name. Periods (.) are known to cause issues in Cargo.
The target is using the same name for $ARCH=wasm32 and $OS=wasi as existing Rust targets. The suffix `preview1` introduced to accurately set expectations because eventually this target will be deprecated and follows [MCP 607](https://github.com/rust-lang/compiler-team/issues/607). The suffix `threads` indicates that it’s an extension that enables threads to the existing target and it follows [MCP 574](https://github.com/rust-lang/compiler-team/issues/574) which describes the rationale behind introducing a separate target.
> - Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
> - The target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
> - The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
> - Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
> - "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
This PR does not introduce any new dependency.
The new target doesn’t support building host tools.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
The full standard library is available for this target as it’s an extension to an existing target that has already supported it.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
Only manual test running is supported at the moment with some tweaks in the test runner codebase. For build and running tests see [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/pull/112922/files#diff-a48ee9d94f13e12be24eadd08eb47b479c153c340eeea4ef22276d876dfd4f3e).
> - Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> - This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
> - Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
> - Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
> - Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> - In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
I acknowledge these requirements and intend to ensure they are met.
Change default panic handler message format.
This changes the default panic hook's message format from:
```
thread '{thread}' panicked at '{message}', {location}
```
to
```
thread '{thread}' panicked at {location}:
{message}
```
This puts the message on its own line without surrounding quotes, making it easiser to read. For example:
Before:
```
thread 'main' panicked at 'env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`', src/main.rs:4:6
```
After:
```
thread 'main' panicked at src/main.rs:4:6:
env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`
```
---
See this PR by `@nyurik,` which does that for only multi-line messages (specifically because of `assert_eq`): https://github.com/rust-lang/rust/pull/111071
This is the change that does that for *all* panic messages.
Re-export core::ffi::FromBytesUntilNulError in std::ffi
Like the other CStr and CString error types, make a re-export for std::ffi::FromBytesUntilNulError.
This seems to have slipped through the cracks in the cstr_from_bytes_until_nul implementation and core_c_str migration.
Tracking Issue: #95027
Make `Debug` representations of `[Lazy, Once]*[Cell, Lock]` consistent with `Mutex` and `RwLock`
`Mutex` prints `<locked>` as a field value when its inner value cannot be accessed, but the lazy types print a fixed string like "`OnceCell(Uninit)`". This could cause confusion if the inner type is a unit type named `Uninit` and does not respect the pretty-printing flag. With this change, the format message is now "`OnceCell(<uninit>)`", consistent with `Mutex`.
Use `LazyLock` to lazily resolve backtraces
By using TAIT to name the initializing closure, `LazyLock` can be used to replace the current `LazilyResolvedCapture`.
merge functionality of `io::Sink` into `io::Empty`
Many times, there is a need for a simple dummy `io::Read`er + `io::Write`r, but currently the only options are `io::Empty` and `io::Sink` respectively. Having both of their functionality together requires writing your own boilerplate for something that makes sense to have in the standard library. This PR adds the functionality of `io::Sink` to `io::Empty`, making `io::Empty` be able to perform the tasks of both of the previous structs. (This idea was first mentioned in #24235)
Note: I also updated some doc comments in `io::utils` in this pull request to fix inconsistencies between `io::Sink` and `io::Empty`.
API Change Proposal: https://github.com/rust-lang/libs-team/issues/49
Make std tests pass on newer Android
Newer versions of Android forbid the creation of hardlinks as well as Unix domain sockets in the /data filesystem via SELinux rules, which causes several tests depending on this behavior to fail. So let's skip these tests on Android if we see an EACCES from one of these syscalls. To achieve this, introduce a macro with the horrible name of or_panic_or_skip_on_android_eacces (better suggestions welcome) which skips (returns from) the test if an EACCES return value is seen on Android.
Add `x86_64-unikraft-linux-musl` target
This introduces `x86_64-unikraft-linux-musl` as the first Rust target for the [Unikraft] Unikernel Development Kit.
[Unikraft]: https://unikraft.org/
Unikraft imitates Linux and uses musl as libc.
It is extremely configurable, and does not even provide a `poll` implementation or a network stack, unless enabled by the end user who compiles the application.
Our approach for integrating the build process with `rustc` is to hide the build process as well as the actual final linking step behind a linker-shim (`kraftld`, see https://github.com/unikraft/kraftkit/issues/612).
## Tier 3 target policy
> - A tier 3 target must have a designated developer or developers (the "target
> maintainers") on record to be CCed when issues arise regarding the target.
> (The mechanism to track and CC such developers may evolve over time.)
I will be the target maintainer.
> - Targets must use naming consistent with any existing targets; for instance, a
> target for the same CPU or OS as an existing Rust target should use the same
> name for that CPU or OS. Targets should normally use the same names and
> naming conventions as used elsewhere in the broader ecosystem beyond Rust
> (such as in other toolchains), unless they have a very good reason to
> diverge. Changing the name of a target can be highly disruptive, especially
> once the target reaches a higher tier, so getting the name right is important
> even for a tier 3 target.
> - Target names should not introduce undue confusion or ambiguity unless
> absolutely necessary to maintain ecosystem compatibility. For example, if
> the name of the target makes people extremely likely to form incorrect
> beliefs about what it targets, the name should be changed or augmented to
> disambiguate it.
> - If possible, use only letters, numbers, dashes and underscores for the name.
> Periods (`.`) are known to cause issues in Cargo.
The target name `x86_64-unikraft-linux-musl` was derived from `x86_64-unknown-linux-musl`, setting Unikraft as vendor.
Unikraft exactly imitates Linux + musl.
> - Tier 3 targets may have unusual requirements to build or use, but must not
> create legal issues or impose onerous legal terms for the Rust project or for
> Rust developers or users.
> - The target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust
> license (`MIT OR Apache-2.0`).
> - The target must not cause the Rust tools or libraries built for any other
> host (even when supporting cross-compilation to the target) to depend
> on any new dependency less permissive than the Rust licensing policy. This
> applies whether the dependency is a Rust crate that would require adding
> new license exceptions (as specified by the `tidy` tool in the
> rust-lang/rust repository), or whether the dependency is a native library
> or binary. In other words, the introduction of the target must not cause a
> user installing or running a version of Rust or the Rust tools to be
> subject to any new license requirements.
> - Compiling, linking, and emitting functional binaries, libraries, or other
> code for the target (whether hosted on the target itself or cross-compiling
> from another target) must not depend on proprietary (non-FOSS) libraries.
> Host tools built for the target itself may depend on the ordinary runtime
> libraries supplied by the platform and commonly used by other applications
> built for the target, but those libraries must not be required for code
> generation for the target; cross-compilation to the target must not require
> such libraries at all. For instance, `rustc` built for the target may
> depend on a common proprietary C runtime library or console output library,
> but must not depend on a proprietary code generation library or code
> optimization library. Rust's license permits such combinations, but the
> Rust project has no interest in maintaining such combinations within the
> scope of Rust itself, even at tier 3.
> - "onerous" here is an intentionally subjective term. At a minimum, "onerous"
> legal/licensing terms include but are *not* limited to: non-disclosure
> requirements, non-compete requirements, contributor license agreements
> (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms,
> requirements conditional on the employer or employment of any particular
> Rust developers, revocable terms, any requirements that create liability
> for the Rust project or its developers or users, or any requirements that
> adversely affect the livelihood or prospects of the Rust project or its
> developers or users.
No dependencies were added to Rust.
Requirements for linking are [Unikraft] and [KraftKit] (both BSD-3-Clause), but none of these are added to Rust.
[KraftKit]: https://github.com/unikraft/kraftkit
> - Neither this policy nor any decisions made regarding targets shall create any
> binding agreement or estoppel by any party. If any member of an approving
> Rust team serves as one of the maintainers of a target, or has any legal or
> employment requirement (explicit or implicit) that might affect their
> decisions regarding a target, they must recuse themselves from any approval
> decisions regarding the target's tier status, though they may otherwise
> participate in discussions.
> - This requirement does not prevent part or all of this policy from being
> cited in an explicit contract or work agreement (e.g. to implement or
> maintain support for a target). This requirement exists to ensure that a
> developer or team responsible for reviewing and approving a target does not
> face any legal threats or obligations that would prevent them from freely
> exercising their judgment in such approval, even if such judgment involves
> subjective matters or goes beyond the letter of these requirements.
Understood.
I am not a member of a Rust team.
> - Tier 3 targets should attempt to implement as much of the standard libraries
> as possible and appropriate (`core` for most targets, `alloc` for targets
> that can support dynamic memory allocation, `std` for targets with an
> operating system or equivalent layer of system-provided functionality), but
> may leave some code unimplemented (either unavailable or stubbed out as
> appropriate), whether because the target makes it impossible to implement or
> challenging to implement. The authors of pull requests are not obligated to
> avoid calling any portions of the standard library on the basis of a tier 3
> target not implementing those portions.
Understood.
`std` is supported.
> - The target must provide documentation for the Rust community explaining how
> to build for the target, using cross-compilation if possible. If the target
> supports running binaries, or running tests (even if they do not pass), the
> documentation must explain how to run such binaries or tests for the target,
> using emulation if possible or dedicated hardware if necessary.
Building is described in the platform support doc.
It will be updated once proper `kraftld` support has landed.
> - Tier 3 targets must not impose burden on the authors of pull requests, or
> other developers in the community, to maintain the target. In particular,
> do not post comments (automated or manual) on a PR that derail or suggest a
> block on the PR based on a tier 3 target. Do not send automated messages or
> notifications (via any medium, including via ``@`)` to a PR author or others
> involved with a PR regarding a tier 3 target, unless they have opted into
> such messages.
> - Backlinks such as those generated by the issue/PR tracker when linking to
> an issue or PR are not considered a violation of this policy, within
> reason. However, such messages (even on a separate repository) must not
> generate notifications to anyone involved with a PR who has not requested
> such notifications.
Understood.
> - Patches adding or updating tier 3 targets must not break any existing tier 2
> or tier 1 target, and must not knowingly break another tier 3 target without
> approval of either the compiler team or the maintainers of the other tier 3
> target.
> - In particular, this may come up when working on closely related targets,
> such as variations of the same architecture with different features. Avoid
> introducing unconditional uses of features that another variation of the
> target may not have; use conditional compilation or runtime detection, as
> appropriate, to let each target run code supported by that target.
I don't think this PR breaks anything.
r? compiler-team
fix docs & example for `std::os::unix::prelude::FileExt::write_at`
Changelog:
* used `File::create` instead of `File::read` to get a writeable file
* explicity mentioned the bug with `pwrite64` in docs
Unfortunately, I don't think that there is really much we can do about this since the feature has already been stabilised.
We could potentially add a clippy lint warning people on Linux that using `write_at` with the `O_APPEND` flag does not exhibit the behaviour that they would have assumed.
fixes#113627
Allow limited access to `OsString` bytes
This extends #109698 to allow no-cost conversion between `Vec<u8>` and `OsString` as suggested in feedback from `os_str_bytes` crate in #111544.
std: remove an allocation in `Path::with_extension`
`Path::with_extension` used to reallocate (and copy) paths twice per call, now it does it once, by checking the size of the previous and new extensions it's possible to call `PathBuf::with_capacity` and pass the exact capacity required.
This also reduces the memory consumption of the path returned from `Path::with_extension` by using exact capacity instead of using amortized exponential growth.
Update documentation for std::process::Command's new method
In the current documentation, it's not specified that when creating a Command, the .exe extension can be omitted for Windows executables. However, for other types of executable files like .bat or .cmd, the complete filename including the extension must be provided.
I encountered it by noticing that `Command::new("wt").spawn().unwrap()` succeeds on my machine while `Command::new("code").spawn().unwrap()` panics. Turns out VS Code's entrypoint is .cmd file.
`resolve_exe` method mentions this behaviour in [a comment](e7fda447e7/library/std/src/sys/windows/process.rs (L425)), but it makes sense to mention it at a more visible place.
I've added this clarification to the documentation, which should make it more accurate and helpful for Rust developers working on the Windows platform.
Implement rust-lang/compiler-team#578.
When an ICE is encountered on nightly releases, the new rustc panic
handler will also write the contents of the backtrace to disk. If any
`delay_span_bug`s are encountered, their backtrace is also added to the
file. The platform and rustc version will also be collected.
In the current documentation, it's not specified that when creating
a Command, the .exe extension can be omitted for Windows executables.
However, for other types of executable files like .bat or .cmd,
the complete filename including the extension must be provided.
I encountered it by noticing that `Command::new("wt").spawn().unwrap()`
succeeds on my machine while `Command::new("code").spawn().unwrap()`
panics. Turns out VS Code's entrypoint is .cmd file.
`resolve_exe` method mentions this behaviour in a comment[1], but it
makes sense to mention it at more visible place.
I've added this clarification to the documentation, which should
make it more accurate and helpful for Rust developers
working on the Windows platform.
[1] e7fda447e7/library/std/src/sys/windows/process.rs (L425)
Like the other CStr and CString error types, make a re-export for
std::ffi::FromBytesUntilNulError.
This seems to have slipped through the cracks in the
cstr_from_bytes_until_nul implementation and core_c_str migration.
Tracking Issue: #95027
Adjustments for RustyHermit
The interface between `libstd` and the OS changed and some changes are not correctly merged for RustHermit. For instance, the crate `hermit_abi` isn't defined as public, although it provided the socket interface for the application.
In addition, the support of thread::available_parallelism is realized. It returns the number of available processors.
Add `Read`, `Write` and `Seek` impls for `Arc<File>` where appropriate
If `&T` implements these traits, `Arc<T>` has no reason not to do so
either. This is useful for operating system handles like `File` or
`TcpStream` which don't need a mutable reference to implement these
traits.
CC #53835.
CC #94744.
move pal cfgs in f32 and f64 to sys
I'd like to push forward on `sys` being a separate crate. To start with, most of these PAL exception cases are very simple little bits of code like this, so I thought I would try tidying them up.
Revert the lexing of `c"…"` string literals
Fixes \[after beta-backport\] #113235.
Further progress is tracked in #113333.
This PR *manually* reverts parts of #108801 (since a git-revert would've been too coarse-grained & messy)
and git-reverts #111647.
CC `@fee1-dead` (#108801) `@klensy` (#111647)
r? `@compiler-errors`
`@rustbot` label F-c_str_literals beta-nominated
`Path::with_extension` used to reallocate (and copy) paths twice per
call, now it does it once, by checking the size of the previous and new
extensions it's possible to call `PathBuf::with_capacity` and pass the
exact capacity it takes.
Also reduce the memory consumption of the path returned from
`Path::with_extension` by using exact capacity instead of using
amortized exponential growth.
Move windows-sys arm32 shim to c.rs
This moves the arm32 shim in to c.rs instead of appending to the generated file itself.
This makes it simpler to change these workarounds if/when needed. The downside is we need to exclude a couple of functions from being generated (see the comment). A metadata solution could help here but they'll be easy enough to add back if that happens.
Remove unnecessary `path` attribute
Follow up to #111401. I missed this at the time but it should now be totally unnecessary since the other include was removed.
r? `@workingjubilee`
Implement `Sync` for `mpsc::Sender`
`mpsc::Sender` is currently `!Sync` because the previous implementation contained an optimization where the channel started out as single-producer and was dynamically upgraded on the first clone, which relied on a unique reference to the sender. This optimization is one of the main reasons the old implementation was so complex and was removed in #93563. `mpsc::Sender` can now soundly implement `Sync`.
Note for any potential confusion, this chance does *not* add MPMC behavior. This only affects the already `Send + Clone` *sender*, not *receiver*.
It's technically possible to rely on the `!Sync` behavior in the same way as a `PhantomData<*mut T>`, but that seems very unlikely in practice. Either way, this change is insta-stable and needs an FCP.
`@rustbot` label +T-libs-api -T-libs
If `&T` implements these traits, `Arc<T>` has no reason not to do so
either. This is useful for operating system handles like `File` or
`TcpStream` which don't need a mutable reference to implement these
traits.
CC #53835.
CC #94744.
Document memory orderings of `thread::{park, unpark}`
Document `thread::park/unpark` as having acquire/release synchronization. Without that guarantee, even the example in the documentation can deadlock:
```rust
let flag = Arc::new(AtomicBool::new(false));
let t2 = thread::spawn(move || {
while !flag.load(Ordering::Acquire) {
thread::park();
}
});
flag.store(true, Ordering::Release);
t2.thread().unpark();
// t1: flag.store(true)
// t1: thread.unpark()
// t2: flag.load() == false
// t2 now parks, is immediately unblocked but never
// acquires the flag, and thus spins forever
```
Multiple calls to `unpark` should also maintain a release sequence to make sure operations released by previous `unpark`s are not lost:
```rust
let a = Arc::new(AtomicBool::new(false));
let b = Arc::new(AtomicBool::new(false));
let t2 = thread::spawn(move || {
while !a.load(Ordering::Acquire) || !b.load(Ordering::Acquire) {
thread::park();
}
});
thread::spawn(move || {
a.store(true, Ordering::Release);
t2.thread().unpark();
});
b.store(true, Ordering::Release);
t2.thread().unpark();
// t1: a.store(true)
// t1: t2.unpark()
// t3: b.store(true)
// t3: t2.unpark()
// t2 now parks, is immediately unblocked but never
// acquires the store of `a`, only the store of `b` which
// was released by the most recent unpark, and thus spins forever
```
This is of course a contrived example, but is reasonable to rely upon in real code.
Note that all implementations of park/unpark already comply with the rules, it's just undocumented.
io: soften ‘at most one write attempt’ requirement in io::Write::write
At the moment, documentation of std::io::Write::write indicates that
call to it ‘represents at most one attempt to write to any wrapped
object’. It seems that such wording was put there to contrast it with
pre-1.0 interface which attempted to write all the data (it has since
been changed in [RFC 517]).
However, the requirement puts unnecessary constraints and may
complicate adaptors which perform non-trivial transformations on the
data. For example, they may maintain an internal buffer which needs
to be written out before the write method accepts more data. It might
be natural to code the method such that it flushes the buffer and then
grabs another chunk of user data. With the current wording in the
documentation, the adaptor would be forced to return Ok(0).
This commit softens the wording such that implementations can choose
code structure which makes most sense for their particular use case.
While at it, elaborate on the meaning of `Ok(0)` return pointing out
that the write_all methods interprets it as an error.
[RFC 517]: https://rust-lang.github.io/rfcs/0517-io-os-reform.html
fix: get the l4re target working again
This is based on work from https://github.com/rust-lang/rust/pull/103966, addressing the review comment by `@m-ou-se` at the time and "fixing" the (probably newly) missing read_buf.
Rollup of 6 pull requests
Successful merges:
- #112352 (Fix documentation build on FreeBSD)
- #112644 (Correct types in method descriptions of `NonZero*` types)
- #112683 (fix ICE on specific malformed asm clobber_abi)
- #112707 ([rustdoc] Fix invalid handling of "going back in history" when "go to only search result" setting is enabled)
- #112719 (Replace fvdl with ffx, allow test without install)
- #112728 (Add `<meta charset="utf-8">` to `-Zdump-mir-spanview` output)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix documentation build on FreeBSD
After the socket ancillary data implementation was introduced, the documentation build was broken on FreeBSD hosts, add the same workaround as for the existing implementations.
Fixes the doc build after #91793
previously it was only able to use BufWriter. This was due to a limitation in the
BufReader generics that prevented specialization. This change works around the issue
by using `where Self: Read` instead of `where I: Read`. This limits our options, e.g.
we can't access BufRead methods, but it happens to work out if we rely on some
implementation details.
Fix building libstd documentation on FreeBSD.
It fixes the following error:
```
error[E0412]: cannot find type `sockcred2` in module `libc`
--> library/std/src/os/unix/net/ancillary.rs:211:29
|
211 | pub struct SocketCred(libc::sockcred2);
| ^^^^^^^^^ not found in `libc`
```
Implement `TryFrom<&OsStr>` for `&str`
Recently when trying to work with `&OsStr` I was surprised to find this `impl` missing.
Since the `to_str` method already existed the actual implementation is fairly non-controversial, except for maybe the choice of the error type. I chose an opaque error here instead of something like `std::str::Utf8Error`, since that would already make a number of assumption about the underlying implementation of `OsStr`.
As this is a trait implementation, it is insta-stable, if I'm not mistaken?
Either way this will need an FCP.
I chose "1.64.0" as the version, since this is unlikely to land before the beta cut-off.
`@rustbot` modify labels: +T-libs-api
API Change Proposal: rust-lang/rust#99031 (accepted)
It fixes the following error:
error[E0412]: cannot find type `sockcred2` in module `libc`
--> library/std/src/os/unix/net/ancillary.rs:211:29
|
211 | pub struct SocketCred(libc::sockcred2);
| ^^^^^^^^^ not found in `libc`
Avoid unwind across `extern "C"` in `thread_local::fast_local`
This is a minimal fix for #112285, in case we want a simple patch that can be easily to backported if that's desirable.
*(Note: I have another broader cleanup which I've mostly omitted from here to avoid clutter, except for the `Cell` change, which isn't needed to fix UB, but simplifies safety comments).*
The only tier-1 target that this occurs on in a way that seems likely to cause problems in practice linux-gnu, although I believe some folks care about that platform somewhat 😉. I'm unsure how big of an issue this is. I've seen stuff like this behave quite badly, but there's a number of reasons to think this might actually be "fine in practice".
I've hedged my bets and assumed we'll backport this at least to beta but my feeling is that there's not enough evidence this is a problem worth backporting further than that.
### More details
This issue seems to have existed since `thread_local!`'s `const` init functionality was added. It occurs if you have a `const`-initialized thread local for a type that `needs_drop`, the drop panics, and you're on a target with support for static thread locals. In this case, we will end up defining an `extern "C"` function in the user crate rather than in libstd, and because the user crate will not have `#![feature(c_unwind)]` enabled, their panic will not be caught by an auto-inserted abort guard.
In practice, the actual situation where problems are likely[^ub] is somewhat narrower.
On most targets with static thread locals, we manage the TLS dtor list by hand (for reentrancy reasons among others). In these cases, while the users code may panic, we're calling it inside our own `extern "C"` (or `extern "system"`) function, which seems to (at least in practice) catch the panic and convert it to an abort.
However, on a few targets, most notably linux-gnu with recent glibc (but also fuchsia and redox), a tls dtor registration mechanism exists which we can actually use directly, [`__cxa_thread_atexit_impl`](https://github.com/rust-lang/rust/blob/master/library/std/src/sys/unix/thread_local_dtor.rs#L26-L36).
This is the case that seems most likely to be a cause for concern, as now we're passing a function to the system library and panicking out of it in a case where there are may not be Rust frames above it on the call stack (since it's running thread shutdown), and even if there were, it may not be prepared to handle such unwinding. If that's the case, it'd be bad.
Is it? Dunno. The fact that it's a `__cxa_*` function makes me think they probably have considered that the callback could throw but I have no evidence here and it doesn't seem to be written down anywhere, so it's just a guess. (I would not be surprised if someone comes into this thread to tell me how definitely-bad-news it is).
That said, as I said, all this is actually UB! If this isn't a "technically UB but fine in practice", but all bets are off if this is the kind of thing we are telling LLVM about.
[^ub]: This is UB so take that with a grain of salt -- I'm absolutely making assumptions about how the UB will behave "in practice" here, which is almost certainly a mistake.
After the socket ancillary data implementation was introduced, the
build was broken on FreeBSD, add the same workaround as for the
existing implementations.
QNX Neutrino: exponential backoff when fork/spawn needs a retry
Fixes#108594: When retrying, sleep with an exponential duration. When sleep duration is lower than minimum possible sleeping time, yield instead (this will not be often due to the exponential increase of duration).
Minimum possible sleeping time is determined using `libc::clock_getres` but only when spawn/fork failed the first time in a request. This is cached using a LazyLock.
CC `@gh-tr`
r? `@workingjubilee`
`@rustbot` label +O-neutrino
use c literals in compiler and library
Use c literals #108801 in compiler and library
currently blocked on:
* <strike>rustfmt: don't know how to format c literals</strike> nope, nightly one works.
* <strike>bootstrap</strike>
r? `@ghost`
`@rustbot` blocked
This fixes the behavior of sending EOF by pressing Ctrl+Z => Enter in a
windows console.
Previously, that would trip the unpaired surrogate error, whereas now we
correctly detect EOF.
Mark internal functions and traits unsafe to reflect preconditions
No semantics are changed in this PR; I only mark some functions and and a trait `unsafe` which already had implicit preconditions. Although it seems somewhat redundant for `numfmt::Part::Copy` to contain a `&[u8]` instead of a `&str`, given that all of its current consumers ultimately expect valid UTF-8. Is the type also intended to work for byte-slice formatting in the future?
Add creation time support to `FileTimes` on apple and windows
Adds support for setting file creation times on platforms which support changing it directly (currently only Apple and Windows). Based on top of #110093 (which was split from this PR).
ACP: rust-lang/libs-team#199 (currently still in progress)
Tracking issue: #98245
`@rustbot` label +T-libs-api -T-libs
Shorten even more panic temporary lifetimes
Followup to #104134. As pointed out by `@bjorn3` in https://github.com/rust-lang/rust/pull/104134#pullrequestreview-1425585948, there are other cases in the panic macros which would also benefit from dropping their non-Send temporaries as soon as possible, avoiding pointlessly holding them across an await point.
For the tests added in this PR, here are the failures you get today on master without the macro changes in this PR:
<details>
<summary>tests/ui/macros/panic-temporaries-2018.rs</summary>
```console
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries-2018.rs:52:18
|
LL | require_send(panic_display());
| ^^^^^^^^^^^^^^^ future returned by `panic_display` is not `Send`
|
= help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries-2018.rs:35:31
|
LL | f(panic!("{}", NOT_SEND)).await;
| -------- ^^^^^- `NOT_SEND` is later dropped here
| | |
| | await occurs here, with `NOT_SEND` maybe used later
| has type `NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries-2018.rs:48:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries-2018.rs:52:18
|
LL | require_send(panic_display());
| ^^^^^^^^^^^^^^^ future returned by `panic_display` is not `Send`
|
= help: within `NotSend`, the trait `Sync` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries-2018.rs:35:31
|
LL | f(panic!("{}", NOT_SEND)).await;
| ---------------------- ^^^^^- the value is later dropped here
| | |
| | await occurs here, with the value maybe used later
| has type `&NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries-2018.rs:48:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries-2018.rs:53:18
|
LL | require_send(panic_str());
| ^^^^^^^^^^^ future returned by `panic_str` is not `Send`
|
= help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries-2018.rs:40:36
|
LL | f(panic!((NOT_SEND, "...").1)).await;
| -------- ^^^^^- `NOT_SEND` is later dropped here
| | |
| | await occurs here, with `NOT_SEND` maybe used later
| has type `NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries-2018.rs:48:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries-2018.rs:54:18
|
LL | require_send(unreachable_display());
| ^^^^^^^^^^^^^^^^^^^^^ future returned by `unreachable_display` is not `Send`
|
= help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries-2018.rs:45:31
|
LL | f(unreachable!(NOT_SEND)).await;
| -------- ^^^^^- `NOT_SEND` is later dropped here
| | |
| | await occurs here, with `NOT_SEND` maybe used later
| has type `NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries-2018.rs:48:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries-2018.rs:54:18
|
LL | require_send(unreachable_display());
| ^^^^^^^^^^^^^^^^^^^^^ future returned by `unreachable_display` is not `Send`
|
= help: within `NotSend`, the trait `Sync` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries-2018.rs:45:31
|
LL | f(unreachable!(NOT_SEND)).await;
| ---------------------- ^^^^^- the value is later dropped here
| | |
| | await occurs here, with the value maybe used later
| has type `&NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries-2018.rs:48:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: aborting due to 5 previous errors
```
</details>
<details>
<summary>tests/ui/macros/panic-temporaries.rs</summary>
```console
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries.rs:42:18
|
LL | require_send(panic_display());
| ^^^^^^^^^^^^^^^ future returned by `panic_display` is not `Send`
|
= help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries.rs:35:31
|
LL | f(panic!("{}", NOT_SEND)).await;
| -------- ^^^^^- `NOT_SEND` is later dropped here
| | |
| | await occurs here, with `NOT_SEND` maybe used later
| has type `NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries.rs:38:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: future cannot be sent between threads safely
--> tests/ui/macros/panic-temporaries.rs:42:18
|
LL | require_send(panic_display());
| ^^^^^^^^^^^^^^^ future returned by `panic_display` is not `Send`
|
= help: within `NotSend`, the trait `Sync` is not implemented for `*const u8`
note: future is not `Send` as this value is used across an await
--> tests/ui/macros/panic-temporaries.rs:35:31
|
LL | f(panic!("{}", NOT_SEND)).await;
| ---------------------- ^^^^^- the value is later dropped here
| | |
| | await occurs here, with the value maybe used later
| has type `&NotSend` which is not `Send`
note: required by a bound in `require_send`
--> tests/ui/macros/panic-temporaries.rs:38:25
|
LL | fn require_send(_: impl Send) {}
| ^^^^ required by this bound in `require_send`
error: aborting due to 2 previous errors
```
</details>
r? bjorn3
add examples of port 0 binding behavior
Was trying to find the method to specify the IP address but not the port, and there wasn't information easily accessible about it in the `TcpListener` or `SocketAddr`. Adding examples to `TcpListener` and `UdpSocket` for clarity.
Don't claim `LocalKey::with` prevents a reference to be sent across threads
The documentation for `LocalKey` claims that `with` yields a reference that cannot be sent across threads, but this is false since you can easily do that with scoped threads. What it actually prevents is the reference from outliving the current thread.
Implement `AsHandle`/`AsSocket` for `Arc`/`Rc`/`Box` on Windows
Implement the Windows counterpart to #97437 and #107317: Implement `AsHandle` and `AsSocket` for `Arc<T>`, `Rc<T>`, and `Box<T>`.
Uplift `clippy::{drop,forget}_{ref,copy}` lints
This PR aims at uplifting the `clippy::drop_ref`, `clippy::drop_copy`, `clippy::forget_ref` and `clippy::forget_copy` lints.
Those lints are/were declared in the correctness category of clippy because they lint on useless and most probably is not what the developer wanted.
## `drop_ref` and `forget_ref`
The `drop_ref` and `forget_ref` lint checks for calls to `std::mem::drop` or `std::mem::forget` with a reference instead of an owned value.
### Example
```rust
let mut lock_guard = mutex.lock();
std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
// still locked
operation_that_requires_mutex_to_be_unlocked();
```
### Explanation
Calling `drop` or `forget` on a reference will only drop the reference itself, which is a no-op. It will not call the `drop` or `forget` method on the underlying referenced value, which is likely what was intended.
## `drop_copy` and `forget_copy`
The `drop_copy` and `forget_copy` lint checks for calls to `std::mem::forget` or `std::mem::drop` with a value that derives the Copy trait.
### Example
```rust
let x: i32 = 42; // i32 implements Copy
std::mem::forget(x) // A copy of x is passed to the function, leaving the
// original unaffected
```
### Explanation
Calling `std::mem::forget` [does nothing for types that implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the value will be copied and moved into the function on invocation.
-----
Followed the instructions for uplift a clippy describe here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
cc `@m-ou-se` (as T-libs-api leader because the uplifting was discussed in a recent meeting)
Start using `windows sys` for Windows FFI bindings in std
Switch to using windows-sys for FFI. In order to avoid some currently contentious issues, this uses windows-bindgen to generate a smaller set of bindings instead of using the full crate.
Unlike the windows-sys crate, the generated bindings uses `*mut c_void` for handle types instead of `isize`. This to sidestep opsem concerns about mixing pointer types and integers between languages. Note that `SOCKET` remains defined as an integer but instead of being a usize, it's changed to fit the [standard library definition](a41fc00eaf/library/std/src/os/windows/raw.rs (L12-L16)):
```rust
#[cfg(target_pointer_width = "32")]
pub type SOCKET = u32;
#[cfg(target_pointer_width = "64")]
pub type SOCKET = u64;
```
The generated bindings also customizes the `#[link]` imports. I hope to switch to using raw-dylib but I don't want to tie that too closely with the switch to windows-sys.
---
Changes outside of the bindings are, for the most part, fairly minimal (e.g. some differences in `*mut` vs. `*const` or a few types differ). One issue is that our own bindings sometimes mix in higher level types, like `BorrowedHandle`. This is pretty adhoc though.
STD support for PSVita
This PR adds std support for `armv7-sony-vita-newlibeabihf` target.
The work here is fairly similar to #95897, just for a different target platform.
This depends on the following pull requests:
rust-lang/backtrace-rs#523rust-lang/libc#3209
enable `rust_2018_idioms` lint group for doctests
With this change, `rust_2018_idioms` lint group will be enabled for compiler/libstd doctests.
Resolves#106086Resolves#99144
Signed-off-by: ozkanonur <work@onurozkan.dev>
Fix MXCSR configuration dependent timing
Dependent on the (potentially secret) data some vector instructions operate on, and the content in MXCSR, instruction retirement may be delayed by one cycle. This is a potential side channel.
This PR fixes this vulnerability for the `x86_64-fortanix-unknown-sgx` platform by loading MXCSR with `0x1fbf` through an `xrstor` instruction when the enclave is entered and executing an `lfence` immediately after. Other changes of the MXCSR happen only when the enclave is about to be exited and no vector instructions will be executed before it will actually do so. Users of EDP who change the MXCSR and do wish to defend against this side channel, will need to implement the software mitigation described [here](https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/best-practices/mxcsr-configuration-dependent-timing.html).
cc: `@jethrogb` `@monokles`
Add FreeBSD cpuset support to `std:🧵:available_concurrency`
Use libc::cpuset_getaffinity to determine the CPUs available to the current process.
The existing sysconf and sysctl paths are left as fallback.
Fix `checked_{add,sub}_duration` incorrectly returning `None` when `other` has more than `i64::MAX` seconds
Use `checked_{add,sub}_unsigned` in `checked_{add,sub}_duration` so that the correct result is returned when adding/subtracting durations with more than `i64::MAX` seconds.
avoid duplicating TLS state between test std and realstd
This basically re-lands https://github.com/rust-lang/rust/pull/100201 and https://github.com/rust-lang/rust/pull/106638, which got reverted by https://github.com/rust-lang/rust/pull/110861. This works around 2 Miri limitations:
- Miri doesn't support the magic linker section that our Windows TLS support relies on, and instead knows where in std to find the symbol that stores the thread callback.
- For macOS, Miri only supports at most one destructor to be registered per thread.
The 2nd would not be very hard to fix (though the intended destructor order is unclear); the first would be a lot of work to fix. Neither of these is a problem for regular Rust code, but in the std test suite we have essentially 2 copies of the std code and then these both become issues. To avoid that we have the std test crate import the TLS code from the real std instead of having its own copy.
r? ``````@m-ou-se``````
Replace generic thread parker with explicit no-op parker
With #98391 merged, all platforms supporting threads now have their own parking implementations. Therefore, the generic implementation can be removed. On the remaining platforms (really just WASM without atomics), parking is not supported, so calls to `thread::park` now return instantly, which is [allowed by their API](https://doc.rust-lang.org/nightly/std/thread/fn.park.html). This is a change in behaviour, as spurious wakeups do not currently occur since all platforms guard against them. It is invalid to depend on this, but I'm still going to tag this as libs-api for confirmation.
````@rustbot```` label +T-libs +T-libs-api +A-atomic
r? rust-lang/libs
Implement tuple<->array convertions via `From`
This PR adds the following impls that convert between homogeneous tuples and arrays of the corresponding lengths:
```rust
impl<T> From<[T; 1]> for (T,) { ... }
impl<T> From<[T; 2]> for (T, T) { ... }
/* ... */
impl<T> From<[T; 12]> for (T, T, T, T, T, T, T, T, T, T, T, T) { ... }
impl<T> From<(T,)> for [T; 1] { ... }
impl<T> From<(T, T)> for [T; 2] { ... }
/* ... */
impl<T> From<(T, T, T, T, T, T, T, T, T, T, T, T)> for [T; 12] { ... }
```
IMO these are quite uncontroversial but note that they are, just like any other trait impls, insta-stable.
Some data-independent timing vector instructions may have subtle data-dependent
timing due to MXCSR configuration; dependent on (potentially secret) data
instruction retirement may be delayed by one cycle.
This can be done by simply changing the `\??\` prefix to `\\?\` and then attempting to convert to a user path.
Currently it simply strips off the prefix which could lead to the wrong path being returned (e.g. if it's not a drive path or if the path contains trailing spaces, etc).
Remove `all` in target_thread_local cfg
I think it was left there by mistake after the previous refactoring. I just came across it while rebasing to master.
Make sure the implementation of TcpStream::as_raw_fd is fully inlined
Currently the following function:
```rust
use std::os::fd::{AsRawFd, RawFd};
use std::net::TcpStream;
pub fn as_raw_fd(socket: &TcpStream) -> RawFd {
socket.as_raw_fd()
}
```
Is optimized to the following:
```asm
example::as_raw_fd:
push rax
call qword ptr [rip + <std::net::tcp::TcpStream as std::sys_common::AsInner<std::sys_common::net::TcpStream>>::as_inner@GOTPCREL]
mov rdi, rax
call qword ptr [rip + std::sys_common::net::TcpStream::socket@GOTPCREL]
mov rdi, rax
pop rax
jmp qword ptr [rip + _ZN73_$LT$std..sys..unix..net..Socket$u20$as$u20$std..os..fd..raw..AsRawFd$GT$9as_raw_fd17h633bcf7e481df8bbE@GOTPCREL]
```
I think it would make more sense to inline trivial functions used within `TcpStream::AsRawFd`.
update wasi_clock_time_api ref.
Closes#110809
>Preview0 corresponded to the import module name wasi_unstable. It was also called snapshot_0 in some places. It was short-lived, and the changes to preview1 were minor, so the focus here is on preview1.
we use the `preview1` doc according to the above quote form [WASI legacy Readme](https://github.com/WebAssembly/WASI/blob/main/legacy/README.md) .
Add 64-bit `time_t` support on 32-bit glibc Linux to `set_times`
Add support to `set_times` for 64-bit `time_t` on 32-bit glibc Linux platforms which have a 32-bit `time_t`. Split from #109773.
Tracking issue: #98245
std docs: edit `PathBuf::set_file_name` example
To make explicit that `set_file_name` might replace or remove the
extension, not just the file stem.
Also edit docs for `Path::with_file_name`, which calls `set_file_name`.
Document `const {}` syntax for `std::thread_local`.
It exists and is pretty cool. More people should use it.
It was added in #83416 and stabilized in #91355 with the tracking issue #84223.
If opening a directory with `FILE_LIST_DIRECTORY` access fails then we should try opening without requesting that access. We may still be able to delete it if it's empty or a link.
Change memory ordering in System wrapper example
Currently, the `SeqCst` ordering is used, which seems unnecessary:
+ Even `Relaxed` ordering guarantees that all updates are atomic and are executed in total order
+ User code only reads atomic for monitoring purposes, no "happens-before" relationships with actual allocations and deallocations are needed for this
If argumentation above is correct, I propose changing ordering to `Relaxed` to clarify that no synchronization is required here, and improve performance (if somebody copy-pastes this example into their code).
Correct `std::prelude` comment
(Read the changed file first for context.)
First, `alloc` has no prelude.
Second, the docs for `v1` don't matter since the [prelude module] already has all the doc links. The `rust_2021` module for instance also doesnt have a convenient doc page. However as I understand glob imports still cant be used because the items dont have the same stabilisation versions.
[prelude module]: https://doc.rust-lang.org/std/prelude/index.html
docs(std): clarify remove_dir_all errors
When using `remove_dir_all`, I assumed that the function was idempotent and that I could always call it to remove a directory if it existed. That's not the case and it bit me in production, so I figured I'd submit this to clarify the docs.
Restructure and rename std thread_local internals to make it less of a maze
Every time I try to work on std's thread local internals, it feels like I'm trying to navigate a confusing maze made of macros, deeply nested modules, and types with multiple names/aliases. Time to clean it up a bit.
This PR:
- Exports `Key` with its own name (`Key`), instead of `__LocalKeyInner`
- Uses `pub macro` to put `__thread_local_inner` into a (unstable, hidden) module, removing `#[macro_export]`, removing it from the crate root.
- Removes the `__` from `__thread_local_inner`.
- Removes a few unnecessary `allow_internal_unstable` features from the macros
- Removes the `libstd_thread_internals` feature. (Merged with `thread_local_internals`.)
- And removes it from the unstable book
- Gets rid of the deeply nested modules for the `Key` definitions (`mod fast` / `mod os` / `mod statik`).
- Turns a `#[cfg]` mess into a single `cfg_if`, now that there's no `#[macro_export]` anymore that breaks with `cfg_if`.
- Simplifies the `cfg_if` conditions to not repeat the conditions.
- Removes useless `normalize-stderr-test`, which were left over from when the `Key` types had different names on different platforms.
- Removes a seemingly unnecessary `realstd` re-export on `cfg(test)`.
This PR changes nothing about the thread local implementation. That's for a later PR. (Which should hopefully be easier once all this stuff is a bit cleaned up.)
Spelling library
Split per https://github.com/rust-lang/rust/pull/110392
I can squash once people are happy w/ the changes. It's really uncommon for large sets of changes to be perfectly acceptable w/o at least some changes.
I probably won't have time to respond until tomorrow or the next day
Fix `std` compilation error for wasi+atomics
Fix https://github.com/rust-lang/rust/issues/109727
It seems that the `unsupported/once.rs` module isn't meant to exist at the same time as the `futex` module, as they have conflicting definitions.
I've solved this by defining the `once` module only if `not(target_feature = "atomics")`.
The `wasm32-unknown-unknown` target [similarly only defines the `once` module if `not(target_feature = "atomics")`](01c4f31927/library/std/src/sys/wasm/mod.rs (L69-L70)).
As show in [this block of code](01c4f31927/library/std/src/sys_common/once/mod.rs (L10-L34)), the `sys::once` module doesn't need to exist if `all(target_arch = "wasm32", target_feature = "atomics")`.
Update documentation wording on path 'try_exists' functions
Just eliminate the quadruple negation in `doesn't silently ignore errors unrelated to ... not existing.`
Limit read size in `File::read_to_end` loop
Fixes#110650.
Windows file reads have perf overhead that's proportional to the buffer size. When we have a reasonable expectation that we know the file size, we can set a reasonable upper bound for the size of the buffer in one read call.
Report allocation errors as panics
OOM is now reported as a panic but with a custom payload type (`AllocErrorPanicPayload`) which holds the layout that was passed to `handle_alloc_error`.
This should be review one commit at a time:
- The first commit adds `AllocErrorPanicPayload` and changes allocation errors to always be reported as panics.
- The second commit removes `#[alloc_error_handler]` and the `alloc_error_hook` API.
ACP: https://github.com/rust-lang/libs-team/issues/192Closes#51540Closes#51245
`Mutex` prints `<locked>` as a field value when its inner value cannot be accessed, but the lazy types print a fixed string like "`OnceCell(Uninit)`". This could cause confusion if the inner type is a unit type named `Uninit` and does not respect the pretty-printing flag. With this change, the format message is now "`OnceCell(<uninit>)`", consistent with `Mutex`.
NotFound errors:
* `ERROR_INVALID_DRIVE`: The system cannot find the drive specified
* `ERROR_BAD_NETPATH`: The network path was not found
* `ERROR_BAD_NET_NAME`: The network name cannot be found.
InvalidFilename:
* `ERROR_BAD_PATHNAME`: The specified path is invalid.
to show this method might replace or remove the extension, not just the
file stem
also edit docs of `Path::with_file_name` because it calls
`PathBuf::set_file_name`
Add Command environment variable inheritance docs
The interaction between the environment variable methods can be confusing. Specifically `env_clear` and `remove_env` have a side effects not mentioned: they disable inheriting environment variables from the parent process. I wanted to fully document this behavior as well as explain relevant edge cases in each of the `Command` env methods.
This is further confused by the return of `get_envs` which will return key/None if `remove_env` has been used, but an empty iterator if `env_clear` has been called. Or a non-empty iterator if `env_clear` was called and later explicit mappings are added. Currently there is no way (that I'm able to find) of observing whether or not the internal `env_clear=true` been toggled on the `Command` struct via its public API.
Ultimately environment variable mappings can be in one of several states:
- Explicitly set value (via `envs` / `env`) will take precedence over parent mapping
- Not explicitly set, will inherit mapping from parent
- Explicitly removed via `remove_env`, this single mapping will not inherit from parent
- Implicitly removed via `env_clear`, no mappings will inherit from parent
I tried to represent this in the relevant sections of the docs.
This is my second-ever doc PR (whoop!). I'm happy to take specific or general doc feedback. Also happy to explain the logic behind any changes or additions I made.
Add `tidy-alphabetical` to features in `alloc` & `std`
So that people have to keep them sorted in future, rather than just sticking them on the end where they conflict more often.
Follow-up to #110269
cc `@jyn514`
Rollup of 9 pull requests
Successful merges:
- #109225 (Clarify that RUST_MIN_STACK may be internally cached)
- #109800 (Improve safe transmute error reporting)
- #110158 (Remove obsolete test case)
- #110180 (don't uniquify regions when canonicalizing)
- #110207 (Assemble `Unpin` candidates specially for generators in new solver)
- #110276 (Remove all but one of the spans in `BoundRegionKind::BrAnon`)
- #110279 (rustdoc: Correctly handle built-in compiler proc-macros as proc-macro and not macro)
- #110298 (Cover edge cases for {f32, f64}.hypot() docs)
- #110299 (Switch to `EarlyBinder` for `impl_subject` query)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Cover edge cases for {f32, f64}.hypot() docs
Fixes#88944
The Euclidean distance is a more general way to express what these functions do, and covers the edge cases of zero and negative inputs.
Does not cover the case of non-normal input values (as the [POSIX docs](https://pubs.opengroup.org/onlinepubs/9699919799.2008edition/) do), but the docs for the rest of the functions in these modules do not address this, I assumed it was not desired.
Clarify that RUST_MIN_STACK may be internally cached
For larger applications it's important that users set `RUST_MIN_STACK` at the start of their program because [`min_stack`](7d3e03666a/library/std/src/sys_common/thread.rs) caches the value. Not doing so can lead to their `env::set_var` call surprisingly not having any effect.
In my own testing `RUST_MIN_STACK` had no effect until I moved it to the top of `main()`. Hopefully this clarification in the docs will help others going forward.
linkat() not available in the system headers of Solaris 10
I've installed rustup on x86_64-unknown-linux-gnu and would like to use the target sparcv9-sun-solaris. For this, I have built a gcc from the source code for cross-compiling to sparcv9-sun-solaris2.10 with system headers of Solaris 10.
With the following hello word example:
main.rs:
```rust
fn main() {
println!("Hello, world!");
}
```
I had a compilation error:
```
$ rustc -v --target sparcv9-sun-solaris -C linker=/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc main.rs
error: linking with `/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc` failed: exit status: 1
|
= note: "/opt/cross-solaris/gcc730/bin/sparcv9-sun-solaris2.10-gcc" "-m64" "/tmp/rustcgebYgj/symbols.o" "main.main.89363361-cgu.0.rcgu.o" "main.main.89363361-cgu.1.rcgu.o" "main.main.89363361-cgu.2.rcgu.o" "main.main.89363361-cgu.3.rcgu.o" "main.main.89363361-cgu.4.rcgu.o" "main.main.89363361-cgu.5.rcgu.o" "main.csypsau9u2r8348.rcgu.o" "-Wl,-z,ignore" "-L" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib" "-Wl,-Bstatic" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd-fa47c8247d587714.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libpanic_unwind-5c87bbe223e6c2a3.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libobject-d484934062ff9fbb.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libmemchr-e8dbd5835abcbf43.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libaddr2line-909ad09329bde2f9.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libgimli-4d74a3be929697ac.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_demangle-47cbe1d7f7271ae1.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd_detect-239fd2d25fb32a00.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libhashbrown-c4a7ce45fb9dec19.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libminiz_oxide-fa6bc3d9bfb4e402.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libadler-419f5a82ddd339a3.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_std_workspace_alloc-7672b378962c11be.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libunwind-0f9e07f0a032c000.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcfg_if-ede7757c356dfb28.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/liblibc-808d56fbc668148a.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/liballoc-784767fe059ad3fe.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/librustc_std_workspace_core-aa31d7ef0556bbe1.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcore-81d07df07db18847.rlib" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libcompiler_builtins-313a510e63006db2.rlib" "-Wl,-Bdynamic" "-lsocket" "-lposix4" "-lpthread" "-lresolv" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lsendfile" "-llgrp" "-L" "/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib" "-o" "main" "-nodefaultlibs"
= note: /opt/cross-solaris/gcc730/lib/gcc/sparcv9-sun-solaris2.10/7.3.0/../../../../sparcv9-sun-solaris2.10/bin/ld: warning: -z ignore ignored.
/home/dlaugt/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/sparcv9-sun-solaris/lib/libstd-fa47c8247d587714.rlib(std-fa47c8247d587714.std.5c42d2c1-cgu.0.rcgu.o): In function `std::sys::unix::fs:🔗:h3683dfbfbb4995cb':
/rustc/897e37553bba8b42751c67658967889d11ecd120/library/std/src/sys/unix/fs.rs:1407: undefined reference to `linkat'
collect2: error: ld returned 1 exit status
= help: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
= note: use the `-l` flag to specify native libraries to link
= note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)
```
linkat() is not available in the system headers of Solaris 10. The hello word example works fine when I build/use rust with this PR change.
don't splice from files into pipes in io::copy
This fixes potential data ordering issue where a write performed after a copy operation could become visible in the copy even though it signaled completion.
I assumed that by not setting `SPLICE_F_MOVE` we would be safe and the kernel would do a copy in kernel space and we could avoid the read-write syscall and copy-to/from-userspace costs. But apparently that flag only makes a difference when splicing from a pipe, but not when splicing into it.
Context: https://lkml.org/lkml/2023/2/9/673
