Use `LazyLock` to lazily resolve backtraces
By using TAIT to name the initializing closure, `LazyLock` can be used to replace the current `LazilyResolvedCapture`.
Stabilize const-weak-new
This is a fairly uncontroversial library stabilization, so I'm going ahead and proposing it to ride the trains to stable.
This stabilizes the following APIs, which are defined to be non-allocating constructors.
```rust
// alloc::rc
impl<T> Weak<T> {
pub const fn new() -> Weak<T>;
}
// alloc::sync
impl<T> Weak<T> {
pub const fn new() -> Weak<T>;
}
```
Closes#95091
``@rustbot`` modify labels: +needs-fcp
Bump its stabilization version several times along
the way to accommodate changes in release processes.
Co-authored-by: Mara Bos <m-ou.se@m-ou.se>
Co-authored-by: Trevor Gross <t.gross35@gmail.com>
`const`-stablilize `NonNull::as_ref`
A bunch of pointer to reference methods have been made unstably const some time ago in #91823 under the feature gate `const_ptr_as_ref`.
Out of these, `NonNull::as_ref` can be implemented as a `const fn` in stable rust today, so i hereby propose to const stabilize this function only.
Tracking issue: #91822
``@rustbot`` label +T-libs-api -T-libs
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
Documentation: Fix Stilted Language in Vec->Indexing
Problem
Language in the Vec->Indexing documentation sounds stilted due to incorrect word ordering: "... type allows to access values by index."
Solution
Reorder words in the Vec->Indexing documentation to flow better: "... type allows access to values by index." The phrase "allows access to" also matches other existing documentation.
Updated lines doc to include trailing carriage return note
Updated `str::lines` doc to include explicit info about (trailing) carriage returns.
Reference: #100311
Clarify behavior of inclusive bounds in BTreeMap::{lower,upper}_bound
It wasn’t quite clear to me how these methods would interpret inclusive bounds so I added examples for those.
Remove redundant example of `BTreeSet::iter`
The usage and that `Values returned by the iterator are returned in ascending order` are already demonstrated by the other example and the description, so I removed the useless one.
Problem
Language in the Vec->Indexing documentation sounds stilted due to
incorrect word ordering: "... type allows to access values by index."
Solution
Reorder words in the Vec->Indexing documentation to flow better:
"... type allows access to values by index." The phrase "allows access to"
also matches other existing documentation.
fix(resolve): update the ambiguity glob binding as warning recursively
Fixes#47525Fixes#56593, but `issue-56593-2.rs` is not fixed to ensure backward compatibility.
Fixes#98467Fixes#105235Fixes#112713
This PR had added a field called `warn_ambiguous` in `NameBinding` which is only for back compatibly reason and used for lint.
More details: https://github.com/rust-lang/rust/pull/112743
r? `@petrochenkov`
Rollup of 7 pull requests
Successful merges:
- #113773 (Don't attempt to compute layout of type referencing error)
- #114107 (Prevent people from assigning me as a PR reviewer)
- #114124 (tests/ui/proc-macro/*: Migrate FIXMEs to check-pass)
- #114171 (Fix switch-stdout test for none unix/windows platforms)
- #114172 (Fix issue_15149 test for the SGX target)
- #114173 (btree/map.rs: remove "Basic usage" text)
- #114174 (doc: replace wrong punctuation mark)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix issue_15149 test for the SGX target
PR https://github.com/rust-lang/rust/pull/112390 moved tests to std. Unfortunately, this caused the `issue_15149` test to be enabled for the SGX target. This is incorrect as the SGX target does not support the `env::current_exe()` call.
Fix switch-stdout test for none unix/windows platforms
PR #112390 moved tests to std. Unfortunately, there is a typo which causes issues on platforms other than unix and windows.
Move two tests from `tests/ui/std` to `library/std/tests`
Hi, there,
This pull request comes from this issue (#99417), sorry I made some mistakes creating the pull request, it's my first one.
docs: fmt::Debug*: Fix comments for finish method.
In the code sample for the `finish` method on `DebugList`, `DebugMap`, and `DebugSet`, refer to finishing the list, map, or set, rather than struct as it did.
Optimize `AtomicBool` for target that don't support byte-sized atomics
`AtomicBool` is defined to have the same layout as `bool`, which means that we guarantee that it has a size of 1 byte. However on certain architectures such as RISC-V, LLVM will emulate byte atomics using a masked CAS loop on an aligned word.
We can take advantage of the fact that `bool` only ever has a value of 0 or 1 to replace `swap` operations with `and`/`or` operations that LLVM can lower to word-sized atomic `and`/`or` operations. This takes advantage of the fact that the incoming value to a `swap` or `compare_exchange` for `AtomicBool` is often a compile-time constant.
### Example
```rust
pub fn swap_true(atomic: &AtomicBool) -> bool {
atomic.swap(true, Ordering::Relaxed)
}
```
### Old
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 255
sllw a2, a2, a0
li a3, 1
sllw a3, a3, a0
slli a3, a3, 32
srli a3, a3, 32
.LBB1_1:
lr.w a4, (a1)
mv a5, a3
xor a5, a5, a4
and a5, a5, a2
xor a5, a5, a4
sc.w a5, a5, (a1)
bnez a5, .LBB1_1
srlw a0, a4, a0
andi a0, a0, 255
snez a0, a0
ret
```
### New
```asm
andi a1, a0, -4
slli a0, a0, 3
li a2, 1
sllw a2, a2, a0
amoor.w a1, a2, (a1)
srlw a0, a1, a0
andi a0, a0, 255
snez a0, a0
ret
```
In the code sample for the `finish` method on `DebugList`,
`DebugMap`, and `DebugSet`, refer to finishing the list, map, or
set, rather than struct as it did.
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.
`AtomicBool` is defined to have the same layout as `bool`, which means
that we guarantee that it has a size of 1 byte. However on certain
architectures such as RISC-V, LLVM will emulate byte atomics using a
masked CAS loop on an aligned word.
We can take advantage of the fact that `bool` only ever has a value of 0
or 1 to replace `swap` operations with `and`/`or` operations that LLVM
can lower to word-sized atomic `and`/`or` operations. This takes
advantage of the fact that the incoming value to a `swap` or
`compare_exchange` for `AtomicBool` is often a compile-time constant.
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
