Add Linux-specific pidfd process extensions (take 2) #81825

voidc · 2021-02-06T13:24:01Z

Continuation of #77168.
I addressed the following concerns from the original PR:

make CommandExt and ChildExt sealed traits
wrap file descriptors in PidFd struct representing ownership over the fd
add take_pidfd to take the fd out of Child
close fd when dropped

Tracking Issue: #82971

rust-highfive · 2021-02-06T13:24:04Z

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Mark-Simulacrum (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

library/std/src/sys/unix/process/process_unix.rs

nicokoch · 2021-02-08T08:09:58Z

library/std/src/sys/unix/process/process_unix.rs

+                            // but that's fine - that just means that multiple threads
+                            // will have tried and failed to execute the same syscall,
+                            // with no other side effects.
+                            Some(libc::ENOSYS) => HAS_CLONE3.store(false, Ordering::Relaxed),


Just checking for ENOSYS is sadly not enough here.
The syscall can also be blocked by seccomp (EPERM).

We have also found cases where new syscalls where randomly broken on some configurations (see the EOPNOTSUPP comment here. Though, I think we can ignore this case for now.

EPERM and EOPNOTSUPP might depend on the arguments of the clone3 call. It would be wrong to set HAS_CLONE3 to false if one of these errors occurred.

In that case the usual approach is to perform the probe separately with arguments that are known to fail with a specific error code, e.g. an invalid combination of flags leading to EINVAL. If that returns EPERM then we know the syscall is filtered. CLONE_SIGHAND | CLONE_CLEAR_SIGHAND could work.

Maybe we could just fallback to fork on EPERM without setting HAS_CLONE3.

That could be considered slightly suboptimal since it'll try again every time in that case, but we already have a preferred path through posix_spawn so this shouldn't be hit too frequently.

My concern was whether it would be possible for clone3 to succeed after having returned EPERM once. In case of ENOSYS we can be certain that any future calls will fail as well. For EPERM, this conclusion does potentially not hold since a seccomp filter could be defined in terms of arbitrary rules.

I don't think we need to account for arbitrary seccomp filters here. seccomp filters should produce ENOSYS, not EPERM.

library/std/src/sys/unix/process/process_unix.rs

library/std/src/os/linux/process.rs

library/std/src/sys/unix/process/process_unix.rs

Mark-Simulacrum · 2021-02-08T23:22:39Z

r? @m-ou-se or perhaps @joshtriplett

library/std/src/sys/unix/process/process_unix.rs

bors · 2021-02-13T06:06:46Z

☔ The latest upstream changes (presumably #82045) made this pull request unmergeable. Please resolve the merge conflicts.

voidc · 2021-03-02T17:37:39Z

@joshtriplett I think you were interested in the original PR. Would you mind taking a look at this?

bors · 2021-03-09T01:57:16Z

☔ The latest upstream changes (presumably #82877) made this pull request unmergeable. Please resolve the merge conflicts.

voidc · 2021-08-01T09:24:46Z

@Aaron1011 Okay, I fixed it! And thanks for seeing to the LLVM fix getting merged so fast! 😃

Aaron1011 · 2021-08-01T16:11:11Z

@bors r=joshtriplett

bors · 2021-08-01T16:11:12Z

📌 Commit 4a832d3 has been approved by joshtriplett

bors · 2021-08-01T16:45:52Z

⌛ Testing commit 4a832d3 with merge 4e21ef2...

bors · 2021-08-01T19:04:31Z

☀️ Test successful - checks-actions
Approved by: joshtriplett
Pushing 4e21ef2 to master...

Aaron1011 · 2021-08-01T19:06:12Z

@voidc: Thanks for all of your work getting this over the finish line!

voidc · 2021-08-01T19:08:53Z

🎉 🎉 Finally! Thanks for your patience @Aaron1011 and @joshtriplett during all of these 200+ comments and 15+ bors runs 😂

brauner · 2021-08-02T07:59:37Z

Thank you all for your work. Very happy to see upstream work make it into this project. :)

Fix `command-create-pidfd` test inside unprivileged Docker containers In `src/test/ui/command/command-create-pidfd.rs` (added rust-lang#81825), the detection code to skip the test on unsupported platforms doesn't account for unprivileged Docker containers (CI uses privileged containers), which leads to a test failure as you can't call the `clone3` syscall in that environment. This PR enhances the detection code to also consider unprivileged containers.

Pkgsrc changes: * Remove one now-longer-applicable patch, adjust a few others * Bump bootstrap requirements to 1.55.0. Upstream changes: Version 1.56.0 (2021-10-21) ======================== Language -------- - [The 2021 Edition is now stable.][rust#88100] See [the edition guide][rust-2021-edition-guide] for more details. - [The pattern in `binding @ pattern` can now also introduce new bindings.] [rust#85305] - [Union field access is permitted in `const fn`.][rust#85769] [rust-2021-edition-guide]: https://doc.rust-lang.org/nightly/edition-guide/rust-2021/index.html Compiler -------- - [Upgrade to LLVM 13.][rust#87570] - [Support memory, address, and thread sanitizers on aarch64-unknown-freebsd.][rust#88023] - [Allow specifying a deployment target version for all iOS targets][rust#87699] - [Warnings can be forced on with `--force-warn`.][rust#87472] This feature is primarily intended for usage by `cargo fix`, rather than end users. - [Promote `aarch64-apple-ios-sim` to Tier 2\*.][rust#87760] - [Add `powerpc-unknown-freebsd` at Tier 3\*.][rust#87370] - [Add `riscv32imc-esp-espidf` at Tier 3\*.][rust#87666] \* Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Allow writing of incomplete UTF-8 sequences via stdout/stderr on Windows.] [rust#83342] The Windows console still requires valid Unicode, but this change allows splitting a UTF-8 character across multiple write calls. This allows, for instance, programs that just read and write data buffers (e.g. copying a file to stdout) without regard for Unicode or character boundaries. - [Prefer `AtomicU{64,128}` over Mutex for Instant backsliding protection.] [rust#83093] For this use case, atomics scale much better under contention. - [Implement `Extend<(A, B)>` for `(Extend<A>, Extend<B>)`][rust#85835] - [impl Default, Copy, Clone for std::io::Sink and std::io::Empty][rust#86744] - [`impl From<[(K, V); N]>` for all collections.][rust#84111] - [Remove `P: Unpin` bound on impl Future for Pin.][rust#81363] - [Treat invalid environment variable names as non-existent.][rust#86183] Previously, the environment functions would panic if given a variable name with an internal null character or equal sign (`=`). Now, these functions will just treat such names as non-existent variables, since the OS cannot represent the existence of a variable with such a name. Stabilised APIs --------------- - [`std::os::unix::fs::chroot`] - [`UnsafeCell::raw_get`] - [`BufWriter::into_parts`] - [`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`] These APIs were previously stable in `std`, but are now also available in `core`. - [`Vec::shrink_to`] - [`String::shrink_to`] - [`OsString::shrink_to`] - [`PathBuf::shrink_to`] - [`BinaryHeap::shrink_to`] - [`VecDeque::shrink_to`] - [`HashMap::shrink_to`] - [`HashSet::shrink_to`] These APIs are now usable in const contexts: - [`std::mem::transmute`] - [`[T]::first`][`slice::first`] - [`[T]::split_first`][`slice::split_first`] - [`[T]::last`][`slice::last`] - [`[T]::split_last`][`slice::split_last`] Cargo ----- - [Cargo supports specifying a minimum supported Rust version in Cargo.toml.] [`rust-version`] This has no effect at present on dependency version selection. We encourage crates to specify their minimum supported Rust version, and we encourage CI systems that support Rust code to include a crate's specified minimum version in the text matrix for that crate by default. Compatibility notes ------------------- - [Update to new argument parsing rules on Windows.][rust#87580] This adjusts Rust's standard library to match the behavior of the standard libraries for C/C++. The rules have changed slightly over time, and this PR brings us to the latest set of rules (changed in 2008). - [Disallow the aapcs calling convention on aarch64][rust#88399] This was already not supported by LLVM; this change surfaces this lack of support with a better error message. - [Make `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` warn by default][rust#87385] - [Warn when an escaped newline skips multiple lines.][rust#87671] - [Calls to `libc::getpid` / `std::process::id` from `Command::pre_exec` may return different values on glibc <= 2.24.][rust#81825] Rust now invokes the `clone3` system call directly, when available, to use new functionality available via that system call. Older versions of glibc cache the result of `getpid`, and only update that cache when calling glibc's clone/fork functions, so a direct system call bypasses that cache update. glibc 2.25 and newer no longer cache `getpid` for exactly this reason. Internal changes ---------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of rustc and related tools. - [LLVM is compiled with PGO in published x86_64-unknown-linux-gnu artifacts.][rust#88069] This improves the performance of most Rust builds. - [Unify representation of macros in internal data structures.][rust#88019] This change fixes a host of bugs with the handling of macros by the compiler, as well as rustdoc. [`std::os::unix::fs::chroot`]: https://doc.rust-lang.org/stable/std/os/unix/fs/fn.chroot.html [`Iterator::intersperse`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse [`Iterator::intersperse_with`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse [`UnsafeCell::raw_get`]: https://doc.rust-lang.org/stable/std/cell/struct.UnsafeCell.html#method.raw_get [`BufWriter::into_parts`]: https://doc.rust-lang.org/stable/std/io/struct.BufWriter.html#method.into_parts [`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`]: rust-lang/rust#84662 [`Vec::shrink_to`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.shrink_to [`String::shrink_to`]: https://doc.rust-lang.org/stable/std/string/struct.String.html#method.shrink_to [`OsString::shrink_to`]: https://doc.rust-lang.org/stable/std/ffi/struct.OsString.html#method.shrink_to [`PathBuf::shrink_to`]: https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.shrink_to [`BinaryHeap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.BinaryHeap.html#method.shrink_to [`VecDeque::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.shrink_to [`HashMap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_map/struct.HashMap.html#method.shrink_to [`HashSet::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_set/struct.HashSet.html#method.shrink_to [`std::mem::transmute`]: https://doc.rust-lang.org/stable/std/mem/fn.transmute.html [`slice::first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first [`slice::split_first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first [`slice::last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.last [`slice::split_last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_last [`rust-version`]: https://doc.rust-lang.org/nightly/cargo/reference/manifest.html#the-rust-version-field [rust#87671]: rust-lang/rust#87671 [rust#86183]: rust-lang/rust#86183 [rust#87385]: rust-lang/rust#87385 [rust#88100]: rust-lang/rust#88100 [rust#86860]: rust-lang/rust#86860 [rust#84039]: rust-lang/rust#84039 [rust#86492]: rust-lang/rust#86492 [rust#88363]: rust-lang/rust#88363 [rust#85305]: rust-lang/rust#85305 [rust#87832]: rust-lang/rust#87832 [rust#88069]: rust-lang/rust#88069 [rust#87472]: rust-lang/rust#87472 [rust#87699]: rust-lang/rust#87699 [rust#87570]: rust-lang/rust#87570 [rust#88023]: rust-lang/rust#88023 [rust#87760]: rust-lang/rust#87760 [rust#87370]: rust-lang/rust#87370 [rust#87580]: rust-lang/rust#87580 [rust#83342]: rust-lang/rust#83342 [rust#83093]: rust-lang/rust#83093 [rust#88177]: rust-lang/rust#88177 [rust#88548]: rust-lang/rust#88548 [rust#88551]: rust-lang/rust#88551 [rust#88299]: rust-lang/rust#88299 [rust#88220]: rust-lang/rust#88220 [rust#85835]: rust-lang/rust#85835 [rust#86879]: rust-lang/rust#86879 [rust#86744]: rust-lang/rust#86744 [rust#84662]: rust-lang/rust#84662 [rust#86593]: rust-lang/rust#86593 [rust#81050]: rust-lang/rust#81050 [rust#81363]: rust-lang/rust#81363 [rust#84111]: rust-lang/rust#84111 [rust#85769]: rust-lang/rust#85769 (comment) [rust#88490]: rust-lang/rust#88490 [rust#88269]: rust-lang/rust#88269 [rust#84176]: rust-lang/rust#84176 [rust#88399]: rust-lang/rust#88399 [rust#88227]: rust-lang/rust#88227 [rust#88200]: rust-lang/rust#88200 [rust#82776]: rust-lang/rust#82776 [rust#88077]: rust-lang/rust#88077 [rust#87728]: rust-lang/rust#87728 [rust#87050]: rust-lang/rust#87050 [rust#87619]: rust-lang/rust#87619 [rust#81825]: rust-lang/rust#81825 (comment) [rust#88019]: rust-lang/rust#88019 [rust#87666]: rust-lang/rust#87666

Pkgsrc changes: * Bump bootstrap kit version to 1.55.0. * Adjust patches as needed, some no longer apply (so removed) * Update checksum adjustments. * Avoid rust-llvm on SunOS * Optionally build docs * Remove reference to closed/old PR#54621 Upstream changes: Version 1.56.1 (2021-11-01) =========================== - New lints to detect the presence of bidirectional-override Unicode codepoints in the compiled source code ([CVE-2021-42574]) [CVE-2021-42574]: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-42574 Version 1.56.0 (2021-10-21) ======================== Language -------- - [The 2021 Edition is now stable.][rust#88100] See [the edition guide][rust-2021-edition-guide] for more details. - [The pattern in `binding @ pattern` can now also introduce new bindings.] [rust#85305] - [Union field access is permitted in `const fn`.][rust#85769] [rust-2021-edition-guide]: https://doc.rust-lang.org/nightly/edition-guide/rust-2021/index.html Compiler -------- - [Upgrade to LLVM 13.][rust#87570] - [Support memory, address, and thread sanitizers on aarch64-unknown-freebsd.] [rust#88023] - [Allow specifying a deployment target version for all iOS targets][rust#87699] - [Warnings can be forced on with `--force-warn`.][rust#87472] This feature is primarily intended for usage by `cargo fix`, rather than end users. - [Promote `aarch64-apple-ios-sim` to Tier 2\*.][rust#87760] - [Add `powerpc-unknown-freebsd` at Tier 3\*.][rust#87370] - [Add `riscv32imc-esp-espidf` at Tier 3\*.][rust#87666] \* Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Allow writing of incomplete UTF-8 sequences via stdout/stderr on Windows.] [rust#83342] The Windows console still requires valid Unicode, but this change allows splitting a UTF-8 character across multiple write calls. This allows, for instance, programs that just read and write data buffers (e.g. copying a file to stdout) without regard for Unicode or character boundaries. - [Prefer `AtomicU{64,128}` over Mutex for Instant backsliding protection.] [rust#83093] For this use case, atomics scale much better under contention. - [Implement `Extend<(A, B)>` for `(Extend<A>, Extend<B>)`][rust#85835] - [impl Default, Copy, Clone for std::io::Sink and std::io::Empty][rust#86744] - [`impl From<[(K, V); N]>` for all collections.][rust#84111] - [Remove `P: Unpin` bound on impl Future for Pin.][rust#81363] - [Treat invalid environment variable names as non-existent.][rust#86183] Previously, the environment functions would panic if given a variable name with an internal null character or equal sign (`=`). Now, these functions will just treat such names as non-existent variables, since the OS cannot represent the existence of a variable with such a name. Stabilised APIs --------------- - [`std::os::unix::fs::chroot`] - [`UnsafeCell::raw_get`] - [`BufWriter::into_parts`] - [`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`] These APIs were previously stable in `std`, but are now also available in `core`. - [`Vec::shrink_to`] - [`String::shrink_to`] - [`OsString::shrink_to`] - [`PathBuf::shrink_to`] - [`BinaryHeap::shrink_to`] - [`VecDeque::shrink_to`] - [`HashMap::shrink_to`] - [`HashSet::shrink_to`] These APIs are now usable in const contexts: - [`std::mem::transmute`] - [`[T]::first`][`slice::first`] - [`[T]::split_first`][`slice::split_first`] - [`[T]::last`][`slice::last`] - [`[T]::split_last`][`slice::split_last`] Cargo ----- - [Cargo supports specifying a minimum supported Rust version in Cargo.toml.] [`rust-version`] This has no effect at present on dependency version selection. We encourage crates to specify their minimum supported Rust version, and we encourage CI systems that support Rust code to include a crate's specified minimum version in the text matrix for that crate by default. Compatibility notes ------------------- - [Update to new argument parsing rules on Windows.][rust#87580] This adjusts Rust's standard library to match the behavior of the standard libraries for C/C++. The rules have changed slightly over time, and this PR brings us to the latest set of rules (changed in 2008). - [Disallow the aapcs calling convention on aarch64][rust#88399] This was already not supported by LLVM; this change surfaces this lack of support with a better error message. - [Make `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` warn by default][rust#87385] - [Warn when an escaped newline skips multiple lines.][rust#87671] - [Calls to `libc::getpid` / `std::process::id` from `Command::pre_exec` may return different values on glibc <= 2.24.][rust#81825] Rust now invokes the `clone3` system call directly, when available, to use new functionality available via that system call. Older versions of glibc cache the result of `getpid`, and only update that cache when calling glibc's clone/fork functions, so a direct system call bypasses that cache update. glibc 2.25 and newer no longer cache `getpid` for exactly this reason. Internal changes ---------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of rustc and related tools. - [LLVM is compiled with PGO in published x86_64-unknown-linux-gnu artifacts.] [rust#88069] This improves the performance of most Rust builds. - [Unify representation of macros in internal data structures.][rust#88019] This change fixes a host of bugs with the handling of macros by the compiler, as well as rustdoc. [`std::os::unix::fs::chroot`]: https://doc.rust-lang.org/stable/std/os/unix/fs/fn.chroot.html [`Iterator::intersperse`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse [`Iterator::intersperse_with`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.intersperse [`UnsafeCell::raw_get`]: https://doc.rust-lang.org/stable/std/cell/struct.UnsafeCell.html#method.raw_get [`BufWriter::into_parts`]: https://doc.rust-lang.org/stable/std/io/struct.BufWriter.html#method.into_parts [`core::panic::{UnwindSafe, RefUnwindSafe, AssertUnwindSafe}`]: rust-lang/rust#84662 [`Vec::shrink_to`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.shrink_to [`String::shrink_to`]: https://doc.rust-lang.org/stable/std/string/struct.String.html#method.shrink_to [`OsString::shrink_to`]: https://doc.rust-lang.org/stable/std/ffi/struct.OsString.html#method.shrink_to [`PathBuf::shrink_to`]: https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.shrink_to [`BinaryHeap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.BinaryHeap.html#method.shrink_to [`VecDeque::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.shrink_to [`HashMap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_map/struct.HashMap.html#method.shrink_to [`HashSet::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_set/struct.HashSet.html#method.shrink_to [`std::mem::transmute`]: https://doc.rust-lang.org/stable/std/mem/fn.transmute.html [`slice::first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first [`slice::split_first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first [`slice::last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.last [`slice::split_last`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_last [`rust-version`]: https://doc.rust-lang.org/nightly/cargo/reference/manifest.html#the-rust-version-field [rust#87671]: rust-lang/rust#87671 [rust#86183]: rust-lang/rust#86183 [rust#87385]: rust-lang/rust#87385 [rust#88100]: rust-lang/rust#88100 [rust#86860]: rust-lang/rust#86860 [rust#84039]: rust-lang/rust#84039 [rust#86492]: rust-lang/rust#86492 [rust#88363]: rust-lang/rust#88363 [rust#85305]: rust-lang/rust#85305 [rust#87832]: rust-lang/rust#87832 [rust#88069]: rust-lang/rust#88069 [rust#87472]: rust-lang/rust#87472 [rust#87699]: rust-lang/rust#87699 [rust#87570]: rust-lang/rust#87570 [rust#88023]: rust-lang/rust#88023 [rust#87760]: rust-lang/rust#87760 [rust#87370]: rust-lang/rust#87370 [rust#87580]: rust-lang/rust#87580 [rust#83342]: rust-lang/rust#83342 [rust#83093]: rust-lang/rust#83093 [rust#88177]: rust-lang/rust#88177 [rust#88548]: rust-lang/rust#88548 [rust#88551]: rust-lang/rust#88551 [rust#88299]: rust-lang/rust#88299 [rust#88220]: rust-lang/rust#88220 [rust#85835]: rust-lang/rust#85835 [rust#86879]: rust-lang/rust#86879 [rust#86744]: rust-lang/rust#86744 [rust#84662]: rust-lang/rust#84662 [rust#86593]: rust-lang/rust#86593 [rust#81050]: rust-lang/rust#81050 [rust#81363]: rust-lang/rust#81363 [rust#84111]: rust-lang/rust#84111 [rust#85769]: rust-lang/rust#85769 (comment) [rust#88490]: rust-lang/rust#88490 [rust#88269]: rust-lang/rust#88269 [rust#84176]: rust-lang/rust#84176 [rust#88399]: rust-lang/rust#88399 [rust#88227]: rust-lang/rust#88227 [rust#88200]: rust-lang/rust#88200 [rust#82776]: rust-lang/rust#82776 [rust#88077]: rust-lang/rust#88077 [rust#87728]: rust-lang/rust#87728 [rust#87050]: rust-lang/rust#87050 [rust#87619]: rust-lang/rust#87619 [rust#81825]: rust-lang/rust#81825 (comment) [rust#88019]: rust-lang/rust#88019 [rust#87666]: rust-lang/rust#87666 Version 1.55.0 (2021-09-09) ============================ Language -------- - [You can now write open "from" range patterns (`X..`), which will start at `X` and will end at the maximum value of the integer.][83918] - [You can now explicitly import the prelude of different editions through `std::prelude` (e.g. `use std::prelude::rust_2021::*;`).][86294] Compiler -------- - [Added tier 3\* support for `powerpc64le-unknown-freebsd`.][83572] \* Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Updated std's float parsing to use the Eisel-Lemire algorithm.][86761] These improvements should in general provide faster string parsing of floats, no longer reject certain valid floating point values, and reduce the produced code size for non-stripped artifacts. - [`string::Drain` now implements `AsRef<str>` and `AsRef<[u8]>`.][86858] Stabilised APIs --------------- - [`Bound::cloned`] - [`Drain::as_str`] - [`IntoInnerError::into_error`] - [`IntoInnerError::into_parts`] - [`MaybeUninit::assume_init_mut`] - [`MaybeUninit::assume_init_ref`] - [`MaybeUninit::write`] - [`array::map`] - [`ops::ControlFlow`] - [`x86::_bittest`] - [`x86::_bittestandcomplement`] - [`x86::_bittestandreset`] - [`x86::_bittestandset`] - [`x86_64::_bittest64`] - [`x86_64::_bittestandcomplement64`] - [`x86_64::_bittestandreset64`] - [`x86_64::_bittestandset64`] The following previously stable functions are now `const`. - [`str::from_utf8_unchecked`] Cargo ----- - [Cargo will now deduplicate compiler diagnostics to the terminal when invoking rustc in parallel such as when using `cargo test`.][cargo/9675] - [The package definition in `cargo metadata` now includes the `"default_run"` field from the manifest.][cargo/9550] - [Added `cargo d` as an alias for `cargo doc`.][cargo/9680] - [Added `{lib}` as formatting option for `cargo tree` to print the `"lib_name"` of packages.][cargo/9663] Rustdoc ------- - [Added "Go to item on exact match" search option.][85876] - [The "Implementors" section on traits no longer shows redundant method definitions.][85970] - [Trait implementations are toggled open by default.][86260] This should make the implementations more searchable by tools like `CTRL+F` in your browser. - [Intra-doc links should now correctly resolve associated items (e.g. methods) through type aliases.][86334] - [Traits which are marked with `#[doc(hidden)]` will no longer appear in the "Trait Implementations" section.][86513] Compatibility Notes ------------------- - [std functions that return an `io::Error` will no longer use the `ErrorKind::Other` variant.][85746] This is to better reflect that these kinds of errors could be categorised [into newer more specific `ErrorKind` variants][79965], and that they do not represent a user error. - [Using environment variable names with `process::Command` on Windows now behaves as expected.][85270] Previously using envionment variables with `Command` would cause them to be ASCII-uppercased. - [Rustdoc will now warn on using rustdoc lints that aren't prefixed with `rustdoc::`][86849] [86849]: rust-lang/rust#86849 [86513]: rust-lang/rust#86513 [86334]: rust-lang/rust#86334 [86260]: rust-lang/rust#86260 [85970]: rust-lang/rust#85970 [85876]: rust-lang/rust#85876 [83572]: rust-lang/rust#83572 [86294]: rust-lang/rust#86294 [86858]: rust-lang/rust#86858 [86761]: rust-lang/rust#86761 [85769]: rust-lang/rust#85769 [85746]: rust-lang/rust#85746 [85305]: rust-lang/rust#85305 [85270]: rust-lang/rust#85270 [84111]: rust-lang/rust#84111 [83918]: rust-lang/rust#83918 [79965]: rust-lang/rust#79965 [87370]: rust-lang/rust#87370 [87298]: rust-lang/rust#87298 [cargo/9663]: rust-lang/cargo#9663 [cargo/9675]: rust-lang/cargo#9675 [cargo/9550]: rust-lang/cargo#9550 [cargo/9680]: rust-lang/cargo#9680 [cargo/9663]: rust-lang/cargo#9663 [`array::map`]: https://doc.rust-lang.org/stable/std/primitive.array.html#method.map [`Bound::cloned`]: https://doc.rust-lang.org/stable/std/ops/enum.Bound.html#method.cloned [`Drain::as_str`]: https://doc.rust-lang.org/stable/std/string/struct.Drain.html#method.as_str [`IntoInnerError::into_error`]: https://doc.rust-lang.org/stable/std/io/struct.IntoInnerError.html#method.into_error [`IntoInnerError::into_parts`]: https://doc.rust-lang.org/stable/std/io/struct.IntoInnerError.html#method.into_parts [`MaybeUninit::assume_init_mut`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.assume_init_mut [`MaybeUninit::assume_init_ref`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.assume_init_ref [`MaybeUninit::write`]: https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.write [`Seek::rewind`]: https://doc.rust-lang.org/stable/std/io/trait.Seek.html#method.rewind [`ops::ControlFlow`]: https://doc.rust-lang.org/stable/std/ops/enum.ControlFlow.html [`str::from_utf8_unchecked`]: https://doc.rust-lang.org/stable/std/str/fn.from_utf8_unchecked.html [`x86::_bittest`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittest.html [`x86::_bittestandcomplement`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandcomplement.html [`x86::_bittestandreset`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandreset.html [`x86::_bittestandset`]: https://doc.rust-lang.org/stable/core/arch/x86/fn._bittestandset.html [`x86_64::_bittest64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittest64.html [`x86_64::_bittestandcomplement64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandcomplement64.html [`x86_64::_bittestandreset64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandreset64.html [`x86_64::_bittestandset64`]: https://doc.rust-lang.org/stable/core/arch/x86_64/fn._bittestandset64.html

The initial stdlib modifications for L4Re just used the linux specifics directly because they were reasonably close to L4Re's behavior. However, this breaks when Linux-specific code relies on code that is only available for the linux target, such as in rust-lang#81825. Put L4Re into its own platform to avoid such breakage in the future. This uses the Linux-specific code as a starting point, which seems to be in line with other OSes with a unix-y interface such as Fuchsia.

rust-highfive assigned Mark-Simulacrum Feb 6, 2021

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 6, 2021

This comment has been minimized.

Sign in to view

voidc commented Feb 6, 2021

View reviewed changes