Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Guarantee that char has the same size and alignment as u32 #116894

Merged
merged 2 commits into from
Nov 4, 2023

Conversation

joshlf
Copy link
Contributor

@joshlf joshlf commented Oct 18, 2023

No description provided.

@rustbot
Copy link
Collaborator

rustbot commented Oct 18, 2023

r? @m-ou-se

(rustbot has picked a reviewer for you, use r? to override)

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Oct 18, 2023
@joshlf
Copy link
Contributor Author

joshlf commented Oct 18, 2023

A change to add the same text to the Reference is here: rust-lang/reference#1401

@traviscross
Copy link
Contributor

@rustbot labels +T-lang -T-libs +I-lang-nominated

This seems entirely a T-lang question, so I'll adjust the labels that way, but if there is some residual T-libs interest here, please relabel of course.

@rustbot rustbot added I-lang-nominated Nominated for discussion during a lang team meeting. T-lang Relevant to the language team, which will review and decide on the PR/issue. and removed T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Oct 24, 2023
@traviscross
Copy link
Contributor

r? @joshtriplett

@rustbot rustbot assigned joshtriplett and unassigned m-ou-se Oct 24, 2023
@joshtriplett
Copy link
Member

@rfcbot merge

@rfcbot
Copy link

rfcbot commented Oct 25, 2023

Team member @joshtriplett has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
See this document for info about what commands tagged team members can give me.

@rfcbot rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Oct 25, 2023
@nikomatsakis
Copy link
Contributor

@rfcbot reviewed

@rfcbot rfcbot added final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. and removed proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. labels Oct 25, 2023
@rfcbot
Copy link

rfcbot commented Oct 25, 2023

🔔 This is now entering its final comment period, as per the review above. 🔔

@RalfJung
Copy link
Member

RalfJung commented Oct 25, 2023 via email

@traviscross
Copy link
Contributor

@rustbot labels -I-lang-nominated

This was discussed and is now in FCP.

@rustbot rustbot removed the I-lang-nominated Nominated for discussion during a lang team meeting. label Oct 25, 2023
@rfcbot rfcbot added finished-final-comment-period The final comment period is finished for this PR / Issue. and removed final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. labels Nov 4, 2023
@rfcbot rfcbot added the to-announce Announce this issue on triage meeting label Nov 4, 2023
@rfcbot
Copy link

rfcbot commented Nov 4, 2023

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

@RalfJung
Copy link
Member

RalfJung commented Nov 4, 2023

@bors r+ rollup

@bors
Copy link
Contributor

bors commented Nov 4, 2023

📌 Commit c278bc1 has been approved by RalfJung

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Nov 4, 2023
bors added a commit to rust-lang-ci/rust that referenced this pull request Nov 4, 2023
…iaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#110340 (Deref docs: expand and remove "smart pointer" qualifier)
 - rust-lang#116894 (Guarantee that `char` has the same size and alignment as `u32`)
 - rust-lang#117534 (clarify that the str invariant is a safety, not validity, invariant)
 - rust-lang#117562 (triagebot no-merges: exclude different case)
 - rust-lang#117570 (fallback for `construct_generic_bound_failure`)
 - rust-lang#117583 (Remove `'tcx` lifetime on `PlaceholderConst`)

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 805a56f into rust-lang:master Nov 4, 2023
11 checks passed
@rustbot rustbot added this to the 1.75.0 milestone Nov 4, 2023
rust-timer added a commit to rust-lang-ci/rust that referenced this pull request Nov 4, 2023
Rollup merge of rust-lang#116894 - joshlf:patch-12, r=RalfJung

Guarantee that `char` has the same size and alignment as `u32`
bors-ferrocene bot added a commit to ferrocene/ferrocene that referenced this pull request Nov 6, 2023
84: Automated pull from upstream `master` r=Dajamante a=github-actions[bot]


This PR pulls the following changes from the upstream repository:

* rust-lang/rust#117585
* rust-lang/rust#117576
* rust-lang/rust#96979
* rust-lang/rust#117191
* rust-lang/rust#117179
* rust-lang/rust#117574
* rust-lang/rust#117537
* rust-lang/rust#117608
  * rust-lang/rust#117596
  * rust-lang/rust#117588
  * rust-lang/rust#117524
  * rust-lang/rust#116017
* rust-lang/rust#117504
* rust-lang/rust#117469
* rust-lang/rust#116218
* rust-lang/rust#117589
* rust-lang/rust#117581
* rust-lang/rust#117503
* rust-lang/rust#117590
  * rust-lang/rust#117583
  * rust-lang/rust#117570
  * rust-lang/rust#117562
  * rust-lang/rust#117534
  * rust-lang/rust#116894
  * rust-lang/rust#110340
* rust-lang/rust#113343
* rust-lang/rust#117579
* rust-lang/rust#117094
* rust-lang/rust#117566
* rust-lang/rust#117564
  * rust-lang/rust#117554
  * rust-lang/rust#117550
  * rust-lang/rust#117343
* rust-lang/rust#115274
* rust-lang/rust#117540
* rust-lang/rust#116412
* rust-lang/rust#115333
* rust-lang/rust#117507
* rust-lang/rust#117538
  * rust-lang/rust#117533
  * rust-lang/rust#117523
  * rust-lang/rust#117520
  * rust-lang/rust#117505
  * rust-lang/rust#117434
* rust-lang/rust#117535
* rust-lang/rust#117510
* rust-lang/rust#116439
* rust-lang/rust#117508



Co-authored-by: Ben Wiederhake <[email protected]>
Co-authored-by: SabrinaJewson <[email protected]>
Co-authored-by: J-ZhengLi <[email protected]>
Co-authored-by: koka <[email protected]>
Co-authored-by: bjorn3 <[email protected]>
Co-authored-by: Joshua Liebow-Feeser <[email protected]>
Co-authored-by: lengyijun <[email protected]>
Co-authored-by: Zalathar <[email protected]>
Co-authored-by: Oli Scherer <[email protected]>
Co-authored-by: Philipp Krones <[email protected]>
Co-authored-by: y21 <[email protected]>
Co-authored-by: bors <[email protected]>
Co-authored-by: bohan <[email protected]>
@apiraino apiraino removed the to-announce Announce this issue on triage meeting label Nov 9, 2023
@RalfJung
Copy link
Member

Note that this does not imply that char and u32 are ABI compatible (i.e., they are passed between functions the same way). That would probably make sense to guarantee by extending the list in the "fn" ptr type docs. (Needs a new PR since FCP already started here.)

I opened a PR for that: #118032.

bors added a commit to rust-lang-ci/rust that referenced this pull request Dec 11, 2023
guarantee that char and u32 are ABI-compatible

In rust-lang#116894 we added a guarantee that `char` has the same alignment as `u32`, but there is still one axis where these types could differ: function call ABI. So let's nail that down as well: in a function signature, `char` and `u32` are completely equivalent.

This is a new stable guarantee, so it will need t-lang approval.
github-actions bot pushed a commit to rust-lang/miri that referenced this pull request Dec 12, 2023
guarantee that char and u32 are ABI-compatible

In rust-lang/rust#116894 we added a guarantee that `char` has the same alignment as `u32`, but there is still one axis where these types could differ: function call ABI. So let's nail that down as well: in a function signature, `char` and `u32` are completely equivalent.

This is a new stable guarantee, so it will need t-lang approval.
netbsd-srcmastr pushed a commit to NetBSD/pkgsrc that referenced this pull request Mar 3, 2024
Pkgsrc changes:
 * Adjust patches and cargo checksums to new versions.
 * For an external LLVM, set dependency of llvm >= 16, in accordance
   with the upstream changes.
 * Mark that on NetBSD we now need >= 9.0, so 8.x is no longer supported.
 * On NetBSD/sparc64 10.x, we now need GCC 12 to build the embedded
   LLVM, which is version 17; apparently GCC 10.4 or 10.5 mis-compiles it,
   resulting in an illegal instruction fault during the build.
   Ref. rust-lang/rust#117231

Upstream changes:

Version 1.75.0 (2023-12-28)
==========================

- [Stabilize `async fn` and return-position `impl Trait` in traits.]
  (rust-lang/rust#115822)
- [Allow function pointer signatures containing `&mut T` in `const` contexts.]
  (rust-lang/rust#116015)
- [Match `usize`/`isize` exhaustively with half-open ranges.]
  (rust-lang/rust#116692)
- [Guarantee that `char` has the same size and alignment as `u32`.]
  (rust-lang/rust#116894)
- [Document that the null pointer has the 0 address.]
  (rust-lang/rust#116988)
- [Allow partially moved values in `match`.]
  (rust-lang/rust#103208)
- [Add notes about non-compliant FP behavior on 32bit x86 targets.]
  (rust-lang/rust#113053)
- [Stabilize ratified RISC-V target features.]
  (rust-lang/rust#116485)

Compiler
--------

- [Rework negative coherence to properly consider impls that only
  partly overlap.] (rust-lang/rust#112875)
- [Bump `COINDUCTIVE_OVERLAP_IN_COHERENCE` to deny, and warn in dependencies.]
  (rust-lang/rust#116493)
- [Consider alias bounds when computing liveness in NLL.]
  (rust-lang/rust#116733)
- [Add the V (vector) extension to the `riscv64-linux-android` target spec.]
  (rust-lang/rust#116618)
- [Automatically enable cross-crate inlining for small functions]
  (rust-lang/rust#116505)
- Add several new tier 3 targets:
    - [`csky-unknown-linux-gnuabiv2hf`]
      (rust-lang/rust#117049)
    - [`i586-unknown-netbsd`]
      (rust-lang/rust#117170)
    - [`mipsel-unknown-netbsd`]
      (rust-lang/rust#117356)

Refer to Rust's [platform support page][platform-support-doc]
for more information on Rust's tiered platform support.

Libraries
---------

- [Override `Waker::clone_from` to avoid cloning `Waker`s unnecessarily.]
  (rust-lang/rust#96979)
- [Implement `BufRead` for `VecDeque<u8>`.]
  (rust-lang/rust#110604)
- [Implement `FusedIterator` for `DecodeUtf16` when the inner iterator does.]
  (rust-lang/rust#110729)
- [Implement `Not, Bit{And,Or}{,Assign}` for IP addresses.]
  (rust-lang/rust#113747)
- [Implement `Default` for `ExitCode`.]
  (rust-lang/rust#114589)
- [Guarantee representation of None in NPO]
  (rust-lang/rust#115333)
- [Document when atomic loads are guaranteed read-only.]
  (rust-lang/rust#115577)
- [Broaden the consequences of recursive TLS initialization.]
  (rust-lang/rust#116172)
- [Windows: Support sub-millisecond sleep.]
  (rust-lang/rust#116461)
- [Fix generic bound of `str::SplitInclusive`'s `DoubleEndedIterator` impl]
  (rust-lang/rust#100806)
- [Fix exit status / wait status on non-Unix `cfg(unix)` platforms.]
  (rust-lang/rust#115108)

Stabilized APIs
---------------

- [`Atomic*::from_ptr`]
  (https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicUsize.html#method.from_ptr)
- [`FileTimes`]
  (https://doc.rust-lang.org/stable/std/fs/struct.FileTimes.html)
- [`FileTimesExt`]
  (https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTimesExt.html)
- [`File::set_modified`]
  (https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_modified)
- [`File::set_times`]
  (https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_times)
- [`IpAddr::to_canonical`]
  (https://doc.rust-lang.org/stable/core/net/enum.IpAddr.html#method.to_canonical)
- [`Ipv6Addr::to_canonical`]
  (https://doc.rust-lang.org/stable/core/net/struct.Ipv6Addr.html#method.to_canonical)
- [`Option::as_slice`]
  (https://doc.rust-lang.org/stable/core/option/enum.Option.html#method.as_slice)
- [`Option::as_mut_slice`]
  (https://doc.rust-lang.org/stable/core/option/enum.Option.html#method.as_mut_slice)
- [`pointer::byte_add`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.byte_add)
- [`pointer::byte_offset`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.byte_offset)
- [`pointer::byte_offset_from`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.byte_offset_from)
- [`pointer::byte_sub`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.byte_sub)
- [`pointer::wrapping_byte_add`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.wrapping_byte_add)
- [`pointer::wrapping_byte_offset`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.wrapping_byte_offset)
- [`pointer::wrapping_byte_sub`]
  (https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.wrapping_byte_sub)

These APIs are now stable in const contexts:

- [`Ipv6Addr::to_ipv4_mapped`]
  (https://doc.rust-lang.org/stable/core/net/struct.Ipv6Addr.html#method.to_ipv4_mapped)
- [`MaybeUninit::assume_init_read`]
  (https://doc.rust-lang.org/stable/core/mem/union.MaybeUninit.html#method.assume_init_read)
- [`MaybeUninit::zeroed`]
  (https://doc.rust-lang.org/stable/core/mem/union.MaybeUninit.html#method.zeroed)
- [`mem::discriminant`]
  (https://doc.rust-lang.org/stable/core/mem/fn.discriminant.html)
- [`mem::zeroed`]
  (https://doc.rust-lang.org/stable/core/mem/fn.zeroed.html)

Cargo
-----

- [Add new packages to `[workspace.members]` automatically.]
  (rust-lang/cargo#12779)
- [Allow version-less `Cargo.toml` manifests.]
  (rust-lang/cargo#12786)
- [Make browser links out of HTML file paths.]
  (rust-lang/cargo#12889)

Rustdoc
-------

- [Accept less invalid Rust in rustdoc.]
  (rust-lang/rust#117450)
- [Document lack of object safety on affected traits.]
  (rust-lang/rust#113241)
- [Hide `#[repr(transparent)]` if it isn't part of the public ABI.]
  (rust-lang/rust#115439)
- [Show enum discriminant if it is a C-like variant.]
  (rust-lang/rust#116142)

Compatibility Notes
-------------------

- [FreeBSD targets now require at least version 12.]
  (rust-lang/rust#114521)
- [Formally demote tier 2 MIPS targets to tier 3.]
  (rust-lang/rust#115238)
- [Make misalignment a hard error in `const` contexts.]
  (rust-lang/rust#115524)
- [Fix detecting references to packed unsized fields.]
  (rust-lang/rust#115583)
- [Remove support for compiler plugins.]
  (rust-lang/rust#116412)
lnicola pushed a commit to lnicola/rust-analyzer that referenced this pull request Apr 7, 2024
guarantee that char and u32 are ABI-compatible

In rust-lang/rust#116894 we added a guarantee that `char` has the same alignment as `u32`, but there is still one axis where these types could differ: function call ABI. So let's nail that down as well: in a function signature, `char` and `u32` are completely equivalent.

This is a new stable guarantee, so it will need t-lang approval.
RalfJung pushed a commit to RalfJung/rust-analyzer that referenced this pull request Apr 27, 2024
guarantee that char and u32 are ABI-compatible

In rust-lang/rust#116894 we added a guarantee that `char` has the same alignment as `u32`, but there is still one axis where these types could differ: function call ABI. So let's nail that down as well: in a function signature, `char` and `u32` are completely equivalent.

This is a new stable guarantee, so it will need t-lang approval.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. finished-final-comment-period The final comment period is finished for this PR / Issue. S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-lang Relevant to the language team, which will review and decide on the PR/issue.
Projects
None yet
Development

Successfully merging this pull request may close these issues.