Tracking Issue for nonnull_provenance #135243

RalfJung · 2025-01-08T09:49:55Z

Feature gate: #![feature(nonnull_provenance)]

This is a tracking issue for some provenance functions on NonNull that were missed in the initial strict provenance stabilization.

Public API

// core::ptr

impl<T> NonNull<T> {
    pub const fn without_provenance(addr: NonZero<usize>) -> Self;
    pub fn from_exposed_provenance(addr: NonZero<usize>) -> Self;
}
impl<T: ?Sized> NonNull<T> {
    pub fn expose_provenance(self) -> NonZero<usize>;
}

Steps / History

ACP: Add expose_provenance and from_exposed_provenance on NonNull libs-team#518
Implementation: add missing provenance APIs on NonNull #135242
Final comment period (FCP)¹
Stabilization PR

Unresolved Questions

None yet.

https://std-dev-guide.rust-lang.org/feature-lifecycle/stabilization.html ↩

The text was updated successfully, but these errors were encountered:

…ratt add missing provenance APIs on NonNull This adds some provenance APIs that exist on raw pointers but have been forgotten on `NonNull`: ```rust impl<T> NonNull<T> { pub const fn without_provenance(addr: NonZero<usize>) -> Self; pub fn from_exposed_provenance(addr: NonZero<usize>) -> Self; } impl<T: ?Sized> NonNull<T> { pub fn expose_provenance(self) -> NonZero<usize>; } ``` rust-lang/libs-team#518 is the ACP for the two exposed provenance ones; I forgot to include `without_provenance` there but I hope that, too, is uncontroversial (and anyway this PR only adds things unstably). Cc `@rust-lang/libs-api` Tracking issue: rust-lang#135243

…ratt add missing provenance APIs on NonNull This adds some provenance APIs that exist on raw pointers but have been forgotten on `NonNull`: ```rust impl<T> NonNull<T> { pub const fn without_provenance(addr: NonZero<usize>) -> Self; pub fn from_exposed_provenance(addr: NonZero<usize>) -> Self; } impl<T: ?Sized> NonNull<T> { pub fn expose_provenance(self) -> NonZero<usize>; } ``` rust-lang/libs-team#518 is the ACP for the two exposed provenance ones; I forgot to include `without_provenance` there but I hope that, too, is uncontroversial (and anyway this PR only adds things unstably). Cc ``@rust-lang/libs-api`` Tracking issue: rust-lang#135243

Rollup merge of rust-lang#135242 - RalfJung:nonnull-provenance, r=jhpratt add missing provenance APIs on NonNull This adds some provenance APIs that exist on raw pointers but have been forgotten on `NonNull`: ```rust impl<T> NonNull<T> { pub const fn without_provenance(addr: NonZero<usize>) -> Self; pub fn from_exposed_provenance(addr: NonZero<usize>) -> Self; } impl<T: ?Sized> NonNull<T> { pub fn expose_provenance(self) -> NonZero<usize>; } ``` rust-lang/libs-team#518 is the ACP for the two exposed provenance ones; I forgot to include `without_provenance` there but I hope that, too, is uncontroversial (and anyway this PR only adds things unstably). Cc `@rust-lang/libs-api` Tracking issue: rust-lang#135243

scottmcm · 2025-01-10T20:03:29Z

This without_provenance taking NonZero is beautiful, since it means that code (in Rc) that used to be NonNull::new_unchecked(ptr::without_provenance(MAX)) can now be safe 👍

…=jhpratt Use `NonNull::without_provenance` within the standard library This API removes the need for several `unsafe` blocks, and leads to clearer code. It uses feature `nonnull_provenance` (rust-lang#135243). Close rust-lang#135343

Rollup merge of rust-lang#135347 - samueltardieu:push-qvyxtxsqyxyr, r=jhpratt Use `NonNull::without_provenance` within the standard library This API removes the need for several `unsafe` blocks, and leads to clearer code. It uses feature `nonnull_provenance` (rust-lang#135243). Close rust-lang#135343

Less unsafe in `dangling`/`without_provenance` This PR was inspired by the new `NonNull::without_provenance` (cc rust-lang#135243 (comment)) since it made me realize that we could write `NonNull::dangling` in completely-safe code using other existing things. Then doing that led me to a few more places that could be simplified, like now that GVN will optimize Transmute-then-PtrToPtr, we can just implement `ptr::without_provenance` by calling `ptr::without_provenance_mut` since the shipped rlib of `core` ends up with the same single statement as the implementation (thanks to GVN merging the steps) and thus there's no need to duplicate the `transmute` -- and more importantly, no need to repeat a long safety comment. There did end up being a couple of other changes needed to avoid exploding certain bits of MIR, though -- like `<Box<[i32]>>::default()`'s MIR originally got way worse as certain things didn't inline, or had a bunch of extraneous UbChecks -- so there's a couple of other changes to solve that.

…ratt add missing provenance APIs on NonNull This adds some provenance APIs that exist on raw pointers but have been forgotten on `NonNull`: ```rust impl<T> NonNull<T> { pub const fn without_provenance(addr: NonZero<usize>) -> Self; pub fn from_exposed_provenance(addr: NonZero<usize>) -> Self; } impl<T: ?Sized> NonNull<T> { pub fn expose_provenance(self) -> NonZero<usize>; } ``` rust-lang/libs-team#518 is the ACP for the two exposed provenance ones; I forgot to include `without_provenance` there but I hope that, too, is uncontroversial (and anyway this PR only adds things unstably). Cc `@rust-lang/libs-api` Tracking issue: rust-lang#135243

…=jhpratt Use `NonNull::without_provenance` within the standard library This API removes the need for several `unsafe` blocks, and leads to clearer code. It uses feature `nonnull_provenance` (rust-lang#135243). Close rust-lang#135343

RalfJung · 2025-05-22T06:24:04Z

@rust-lang/libs-api I'd like to nominate this for stabilization. This is the "obvious" way to fill the gaps in the exposed provenance APIs for NonNull; a few functions have simply been forgotten when we did the original stabilization.

Amanieu · 2025-05-22T13:23:55Z

@rfcbot merge

rfcbot · 2025-05-22T13:23:57Z

Team member @Amanieu 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!

See this document for info about what commands tagged team members can give me.

rfcbot · 2025-05-29T12:23:49Z

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

rfcbot · 2025-06-08T12:28:17Z

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 · 2025-06-09T10:37:00Z

Stabilization PR: #142238

…kingjubilee stabilize nonnull_provenance Fixes rust-lang#135243 FCP passed in rust-lang#135243

Rollup merge of #142238 - RalfJung:nonnull_provenance, r=workingjubilee stabilize nonnull_provenance Fixes #135243 FCP passed in #135243

stabilize nonnull_provenance Fixes rust-lang/rust#135243 FCP passed in rust-lang/rust#135243

RalfJung added C-tracking-issue Category: An issue tracking the progress of sth. like the implementation of an RFC T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. labels Jan 8, 2025

This was referenced Jan 8, 2025

Add expose_provenance and from_exposed_provenance on NonNull rust-lang/libs-team#518

Closed

add missing provenance APIs on NonNull #135242

Merged

scottmcm mentioned this issue Jan 10, 2025

Update the standard library to use the new NonNull::without_provenance #135343

Closed

scottmcm mentioned this issue Jan 10, 2025

Less unsafe in dangling/without_provenance #135344

Merged

samueltardieu mentioned this issue Jan 10, 2025

Use NonNull::without_provenance within the standard library #135347

Merged

RalfJung added the I-libs-api-nominated Nominated for discussion during a libs-api team meeting. label May 22, 2025

rfcbot added the proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. label May 22, 2025

Amanieu removed proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. I-libs-api-nominated Nominated for discussion during a libs-api team meeting. labels May 22, 2025

rfcbot added disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. labels May 22, 2025

rfcbot added the finished-final-comment-period The final comment period is finished for this PR / Issue. label Jun 8, 2025

rfcbot added to-announce Announce this issue on triage meeting and removed final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. labels Jun 8, 2025

rustbot mentioned this issue Jun 8, 2025

Tracking issue for release notes of #135243: Tracking Issue for nonnull_provenance #142190

Open

RalfJung mentioned this issue Jun 9, 2025

stabilize nonnull_provenance #142238

Merged

tgross35 added a commit to tgross35/rust that referenced this issue Jun 9, 2025

Rollup merge of rust-lang#142238 - RalfJung:nonnull_provenance, r=wor…

fd06f6d

…kingjubilee stabilize nonnull_provenance Fixes rust-lang#135243 FCP passed in rust-lang#135243

bors closed this as completed in #142238 Jun 9, 2025

rust-timer added a commit that referenced this issue Jun 9, 2025

Unrolled build for #142238

df121b6

Rollup merge of #142238 - RalfJung:nonnull_provenance, r=workingjubilee stabilize nonnull_provenance Fixes #135243 FCP passed in #135243

tgross35 added a commit to tgross35/compiler-builtins that referenced this issue Jun 9, 2025

Rollup merge of #142238 - RalfJung:nonnull_provenance, r=workingjubilee

d37806c

stabilize nonnull_provenance Fixes rust-lang/rust#135243 FCP passed in rust-lang/rust#135243

github-actions bot pushed a commit to rust-lang/miri that referenced this issue Jun 10, 2025

Rollup merge of #142238 - RalfJung:nonnull_provenance, r=workingjubilee

f87ab39

stabilize nonnull_provenance Fixes rust-lang/rust#135243 FCP passed in rust-lang/rust#135243

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Tracking Issue for nonnull_provenance #135243

Tracking Issue for nonnull_provenance #135243

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Tracking Issue for nonnull_provenance #135243

Tracking Issue for nonnull_provenance #135243

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Public API

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