Amend style guide section for formatting where clauses in type aliases
This PR has two parts:
1. Amend wording about breaking before or after the `=`, which is a style guide bugfix to align it with current rustfmt behavior.
2. Explain how to format trailing (#89122) where clauses, which are preferred in both GATs (#90076) and type aliases (#114662).
r? `@joshtriplett`
Update books
## rust-embedded/book
1 commits in 99ad2847b865e96d8ae7b333d3ee96963557e621..eac173690b8cc99094e1d88bd49dd61127fbd285
2023-09-12 07:34:44 UTC to 2023-09-12 07:34:44 UTC
- USB connector-type correction (rust-embedded/book#360)
## rust-lang/nomicon
1 commits in e3f3af69dce71cd37a785bccb7e58449197d940c..ddfa4214487686e91b21aa29afb972c08a8f0d5b
2023-09-22 17:04:10 UTC to 2023-09-22 17:04:10 UTC
- Fill "Beneath `std`" (rust-lang/nomicon#413)
## rust-lang/reference
1 commits in ee7c676fd6e287459cb407337652412c990686c0..5262e1c3b43a2c489df8f6717683a44c7a2260fd
2023-09-18 18:28:31 UTC to 2023-09-18 18:28:31 UTC
- we reserve the right to reduce our amount of UB (rust-lang/reference#1397)
## rust-lang/rustc-dev-guide
8 commits in 08bb147d51e815b96e8db7ba4cf870f201c11ff8..a13b7c28ed705891c681ce5417b3d1cdb12cecd1
2023-09-25 05:14:41 UTC to 2023-09-11 21:29:18 UTC
- Clarify all the `{AP,RP}IT{,IT}` impl trait types (rust-lang/rustc-dev-guide#1798)
- Modify build instructions for optimized build (rust-lang/rustc-dev-guide#1795)
- Remove outdated references to coverage debug code (rust-lang/rustc-dev-guide#1797)
- Add deep dive document about early/late bound parameters interacting with turbofish (rust-lang/rustc-dev-guide#1794)
- explain the MIR const vs TY const situation (rust-lang/rustc-dev-guide#1793)
- fix type name (rust-lang/rustc-dev-guide#1792)
- Clarify that `run-coverage` only runs in some of the CI jobs (rust-lang/rustc-dev-guide#1791)
- Document the `coverage-map` and `run-coverage` test suites (rust-lang/rustc-dev-guide#1790)
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>
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>
style-guide: Document formatting of `as` casts (mostly like a binary operator)
`as` casts currently get formatted like a binary operator, except that
the second line can stack several `as` casts rather than breaking them
each onto their own line. Document this.
As far as I can tell (cc `@calebcartwright` for verification), this is not a 2024 edition change, it just documents current behavior.
rustdoc-search: add support for type parameters
r? `@GuillaumeGomez`
## Preview
* https://notriddle.com/rustdoc-html-demo-4/advanced-search/rustdoc/read-documentation/search.html
* https://notriddle.com/rustdoc-html-demo-4/advanced-search/std/index.html?search=option%3Coption%3CT%3E%3E%20-%3E%20option%3CT%3E
* https://notriddle.com/rustdoc-html-demo-4/advanced-search/std/index.html?search=option%3CT%3E,%20E%20-%3E%20result%3CT,%20E%3E
* https://notriddle.com/rustdoc-html-demo-4/advanced-search/std/index.html?search=-%3E%20option%3CT%3E
## Description
When writing a type-driven search query in rustdoc, specifically one with more than one query element, non-existent types become generic parameters instead of auto-correcting (which is currently only done for single-element queries) or giving no result. You can also force a generic type parameter by writing `generic:T` (and can force it to not use a generic type parameter with something like `struct:T` or whatever, though if this happens it means the thing you're looking for doesn't exist and will give you no results).
There is no syntax provided for specifying type constraints for generic type parameters.
When you have a generic type parameter in a search query, it will only match up with generic type parameters in the actual function, not concrete types that match, not concrete types that implement a trait. It also strictly matches based on when they're the same or different, so `option<T>, option<U> -> option<U>` matches `Option::and`, but not `Option::or`. Similarly, `option<T>, option<T> -> option<T>` matches `Option::or`, but not `Option::and`.
## Motivation
This feature is motivated by the many "combinitor"-type functions found in generic libraries, such as Option, Future, Iterator, and Entry. These highly-generic functions have names that are almost completely arbitrary, and a type signature that tells you what it actually does.
This PR is a major step towards[^closure] being able to easily search for generic functions by their type signature instead of by name. Some examples of combinators that can be found using this PR (try them out in the preview):
* `option<option<T>> -> option<T>` returns Option::flatten
* `option<T> -> result<T>` returns Option::ok_or
* `option<result<T>> -> result<option<T>>` returns Option::transpose
* `entry<K, V>, FnOnce -> V` returns `Entry::or_insert_with` (and `or_insert_with_key`, since there's no way to specify the generics on FnOnce)
[^closure]:
For this feature to be as useful as it ought to be, you should be able to search for *trait-associated types* and *closures*. This PR does not implement either of these: they are **Future possibilities**.
Trait-associated types would allow queries like `option<T> -> iterator<item=T>` to return `Option::iter`. We should also allow `option<T> -> iterator<T>` to match the associated type version.
Closures would make a good way to query for things like `Option::map`. Closure support needs associated types to be represented in the search index, since `FnOnce() -> i32` desugars to `FnOnce<Output=i32, ()>`, so associated trait types should be implemented first. Also, we'd want to expose an easy way to query closures without specifying which of the three traits you want.
Rework `no_coverage` to `coverage(off)`
As discussed at the tail of https://github.com/rust-lang/rust/issues/84605 this replaces the `no_coverage` attribute with a `coverage` attribute that takes sub-parameters (currently `off` and `on`) to control the coverage instrumentation.
Allows future-proofing for things like `coverage(off, reason="Tested live", issue="#12345")` or similar.
Add `i686-pc-windows-gnullvm` triple
With various fixes that are already present in the code, a fully working i686 target can join other targets in `*-windows-gnullvm` family. Again this will be mostly useful for MSYS2 right now but I plan to open MCP for providing at least prebuilt std for `windows-gnullvm` as the next step which will expand usability of these targets.
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, MSYS2 is one of interested consumers. Previously added `gnullvm` triples proved there is not much maintenance required.
> 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 triple name is consistent with other targets and was discussed at [`t-compiler/LLVM+mingw-w64 Windows targets`](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/LLVM.2Bmingw-w64.20Windows.20targets)
> 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.
It's even more liberal than already existing `*-pc-windows-gnu`.
> 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.
Again 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 seems to work, at least for cross compilation.
> 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 platform support doc, running tests doesn't work right now (without hacks) because Rust's build system doesn't seem to support testing targets built from `.json`.
Docs will be updated once this lands in beta allowing master branch to build and run tests without `.json` files.
> 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.
MCP661: Move wasm32-wasi-preview1-threads target to Tier 2
https://github.com/rust-lang/compiler-team/issues/661
>A tier 2 target must have value to people other than its maintainers. (It may still be a niche target, but it must not be exclusively useful for an inherently closed group.)
The feature is already implemented in [wasi-sdk(](https://github.com/WebAssembly/wasi-sdk) (C toolchain for WASM), and four different WASM runtimes([Wasmtime](https://github.com/bytecodealliance/wasmtime), [WAMR](https://github.com/bytecodealliance/wasm-micro-runtime), [Wasmer](https://github.com/wasmerio/wasmer), [toywasm](https://github.com/yamt/toywasm)) are compatible with it.
>A tier 2 target must have a designated team of developers (the "target maintainers") available to consult on target-specific build-breaking issues, or if necessary to develop target-specific language or library implementation details. This team must have at least 2 developers.
>The target maintainers should not only fix target-specific issues, but should use any such issue as an opportunity to educate the Rust community about portability to their target, and enhance documentation of the target.
We already have a team of 4 developers. See [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/blob/master/src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md). The documentation is being updated in this PR as the first occurrence.
>The target must not place undue burden on Rust developers not specifically concerned with that target. Rust developers are expected to not gratuitously break a tier 2 target, but are not expected to become experts in every tier 2 target, and are not expected to provide target-specific implementations for every tier 2 target.
It doesn't as it’s built on top of existing wasm32-wasi tier-2 target and it only extends stdlib by implementing
std:: thread::spawn/join.
> The target must provide documentation for the Rust community explaining how to build for the target using cross-compilation, and explaining how to run tests for the target. If at all possible, this documentation should show how to run Rust programs and tests for the target using emulation, to allow anyone to do so. If the target cannot be feasibly emulated, the documentation should explain how to obtain and work with physical hardware, cloud systems, or equivalent.
For build and running tests see *Building Rust programs* and *Testing* in [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/blob/master/src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md). Only manual test running is supported at the moment with some tweaks in the test runner codebase.
> The target must document its baseline expectations for the features or versions of CPUs, operating systems, libraries, runtime environments, and similar.
See *Platform requirements* in [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/blob/master/src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md)
> If introducing a new tier 2 or higher target that is identical to an existing Rust target except for the baseline expectations for the features or versions of CPUs, operating systems, libraries, runtime environments, and similar, then the proposed target must document to the satisfaction of the approving teams why the specific difference in baseline expectations provides sufficient value to justify a separate target.
>Note that in some cases, based on the usage of existing targets within the Rust community, Rust developers or a target's maintainers may wish to modify the baseline expectations of a target, or split an existing target into multiple targets with different baseline expectations. A proposal to do so will be treated similarly to the analogous promotion, demotion, or removal of a target, according to this policy, with the same team approvals required.
>For instance, if an OS version has become obsolete and unsupported, a target for that OS may raise its baseline expectations for OS version (treated as though removing a target corresponding to the older versions), or a target for that OS may split out support for older OS versions into a lower-tier target (treated as though demoting a target corresponding to the older versions, and requiring justification for a new target at a lower tier for the older OS versions).
Justified in https://github.com/rust-lang/compiler-team/issues/574 and I acknowledge these requirements and intend to ensure they are met.
> Tier 2 targets must not leave any significant portions of core or the standard library unimplemented or stubbed out, unless they cannot possibly be supported on the target.
>The right approach to handling a missing feature from a target may depend on whether the target seems likely to develop the feature in the future. In some cases, a target may be co-developed along with Rust support, and Rust may gain new features on the target as that target gains the capabilities to support those features.
>As an exception, a target identical to an existing tier 1 target except for lower baseline expectations for the OS, CPU, or similar, may propose to qualify as tier 2 (but not higher) without support for std if the target will primarily be used in no_std applications, to reduce the support burden for the standard library. In this case, evaluation of the proposed target's value will take this limitation into account.
It does not, as it’s built as an extension of the existing tier 2 target (wasm32-wasi).
> The code generation backend for the target should not have deficiencies that invalidate Rust safety properties, as evaluated by the Rust compiler team. (This requirement does not apply to arbitrary security enhancements or mitigations provided by code generation backends, only to those properties needed to ensure safe Rust code cannot cause undefined behavior or other unsoundness.) If this requirement does not hold, the target must clearly and prominently document any such limitations as part of the target's entry in the target tier list, and ideally also via a failing test in the testsuite. The Rust compiler team must be satisfied with the balance between these limitations and the difficulty of implementing the necessary features.
>For example, if Rust relies on a specific code generation feature to ensure that safe code cannot overflow the stack, the code generation for the target should support that feature.
>If the Rust compiler introduces new safety properties (such as via new capabilities of a compiler backend), the Rust compiler team will determine if they consider those new safety properties a best-effort improvement for specific targets, or a required property for all Rust targets. In the latter case, the compiler team may require the maintainers of existing targets to either implement and confirm support for the property or update the target tier list with documentation of the missing property.
Doesn't apply, the target re-uses existing backend and doesn't extend it
> If the target supports C code, and the target has an interoperable calling convention for C code, the Rust target must support that C calling convention for the platform via extern "C". The C calling convention does not need to be the default Rust calling convention for the target, however.
Target does not support C code
>The target must build reliably in CI, for all components that Rust's CI considers mandatory.
The target reliably builds in CI already https://github.com/rust-lang/rust/blob/master/src/ci/docker/host-x86_64/dist-various-2/Dockerfile#L143.
>The approving teams may additionally require that a subset of tests pass in CI, such as enough to build a functional "hello world" program, ./x.py test --no-run, or equivalent "smoke tests". In particular, this requirement may apply if the target builds host tools, or if the tests in question provide substantial value via early detection of critical problems.
The existing tier-2 target and this target as its extension [pass](https://github.com/rust-lang/rust/pull/112922#issuecomment-1634514924) for 14.5k+ tests/ui when tests are run manually(described in *Testing* in in [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/blob/master/src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md). Can be tested in the CI as soon as the original target does.
> Building the target in CI must not take substantially longer than the current slowest target in CI, and should not substantially raise the maintenance burden of the CI infrastructure. This requirement is subjective, to be evaluated by the infrastructure team, and will take the community importance of the target into account.
It doesn’t as it only slightly extends standard library of the existing target
> Tier 2 targets should, if at all possible, support cross-compiling. Tier 2 targets should not require using the target as the host for builds, even if the target supports host tools.
N/a given as it only extends stdlib of the existing target.
> In addition to the legal requirements for all targets (specified in the tier 3 requirements), because a tier 2 target typically involves the Rust project building and supplying various compiled binaries, incorporating the target and redistributing any resulting compiled binaries (e.g. built libraries, host tools if any) must not impose any onerous license requirements on any members of the Rust project, including infrastructure team members and those operating CI systems. This is a subjective requirement, to be evaluated by the approving teams.
>As an exception to this, if the target's primary purpose is to build components for a Free and Open Source Software (FOSS) project licensed under "copyleft" terms (terms which require licensing other code under compatible FOSS terms), such as kernel modules or plugins, then the standard libraries for the target may potentially be subject to copyleft terms, as long as such terms are satisfied by Rust's existing practices of providing full corresponding source code. Note that anything added to the Rust repository itself must still use Rust's standard license terms.
Requirement are met, no legal issues.
> Tier 2 targets must not impose burden on the authors of pull requests, or other developers in the community, to ensure that tests pass for 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 tests failing for the target. Do not send automated messages or notifications (via any medium, including via `````@)````` to a PR author or others involved with a PR regarding the PR breaking tests on a tier 2 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.
I acknowledge these requirements and intend to ensure they are met.
> The target maintainers should regularly run the testsuite for the target, and should fix any test failures in a reasonably timely fashion.
The tests are run manually every week by `````@g0djan````` now.
While target has been in Tier 3, 2 issues(https://github.com/rust-lang/rust/issues/114608 and https://github.com/rust-lang/rust/issues/114610) have been raised. Both issues were addressed the same day and fixes has been merged by now.
> All requirements for tier 3 apply.
Target was initially accepted as a Tier 3 target in https://github.com/rust-lang/rust/pull/112922 .
Description of the `PATH` option:
> A filepath may optionally be specified for each requested information
> kind, in the format `--print KIND=PATH`, just like for `--emit`. When
> a path is specified, information will be written there instead of to
> stdout.
Reassign sparc-unknown-none-elf to tier 3
It should never have been moved to tier 2. It is a new platform and the maintainer has agreed to do tier 3 maintenance for it, not tier 2.
r? `@jonathanpallant`
Fix table issues in platform support documentation (closes#115047)
mdBook needs an empty line before and after the table block.
In addition, in the tier-3 list three targets forgot about the host column and therefore showed the notes in the host column.
Closes#115047
