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().
Fix switch_stdout_to on Windows7
The `switch_stdout_to` test was broken on Windows7, as deleting the temporary test folder would fail since the `switch-stdout-output` file we redirected the stdout to is never closed, and it's impossible on Win7 to delete an opened file.
To fix this issue, we make `switch_stdout_to` return the previous handle. Using this, we add a new `switch_stdout_to` call at the end of the test to return the stdio handles to their original state, and recover the handle to the file we opened. This handle is automatically closed at the end of the function, which should allow the temporary test folder to be deleted properly.
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>
The switch_stdout_to test was broken on Windows7, as the test
infrastructure would refuse to delete the temporary test folder because
the switch-stdout-output file we redirected the stdout to was still
opened.
To fix this issue, we make switch_stdout_to return the previous handle,
and add a new switch_stdout_to call at the end of the test to return the
stdio handles to their original state. The handle the second
switch_stdout_to returns will be automatically closed, which should
allow the temporary test folder to be deleted properly.
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
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.`
Tomoaki Kawada