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document that the null pointer has the 0 address #116988
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r? @thomcc (rustbot has picked a reviewer for you, use r? to override) |
Notably these functions only work on @rfcbot fcp merge |
Team member @scottmcm 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. |
@rustbot labels +I-lang-nominated I'm going to nominate even though FCP has been proposed so that this comes up at least once in the meeting. |
@rfcbot reviewed |
@traviscross Doesn't our agenda generator include proposed FCPs already? We already have quite a long list of nominated issues; I don't think nominating every newly proposed FCP is helping with that. (edit: I am specifically pushing back on nominating for the purpose of getting eyes and checkboxes on the FCP. If your goal is to spark a discussion within the lang team meeting, then nominating is good for that.) |
From #116895 (comment) it sounds like you've already considered the implications for provenance. With those aside I think we should go ahead and commit to this. @rfcbot reviewed |
🔔 This is now entering its final comment period, as per the review above. 🔔 |
Yeah, the good thing is that nobody expects to be able to load from a null ptr so provenance basically does not matter. |
Yes, all p-FCPs are included in the meeting in the section that starts with
So I interpreted the nomination here as "please p-fcp merge this", which is why I removed nomination after doing that. Checking boxes is generally something that should be done asynchronously via the https://rfcbot.rs/ list, so that the synchronous time in triage can be spent on things with specific questions in the nomination. |
This is not a blocker for this issue, but could we please get a comment somewhere appropriate that says what code should do in the rare case where it has memory mapped at 0 and needs to write to it? (e.g. low-level hardware programming, or weird userspace programming situations that need the zero page mapped.) We should identify what function will allow such a write without complaint, and point people to that. |
Currently there is no way to write such code in Rust, you have to use inline asm. rust-lang/unsafe-code-guidelines#29 tracks providing support for this.
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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. |
@thomcc this should be ready to land then :) |
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Since this is only a documentation change and the semantic was approved by T-lang, I'll go ahead and merge this. Feel free to r- if you think that a T-libs review is required.
@bors r+ rollup |
☀️ Test successful - checks-actions |
Finished benchmarking commit (b049093): comparison URL. Overall result: no relevant changes - no action needed@rustbot label: -perf-regression Instruction countThis benchmark run did not return any relevant results for this metric. Max RSS (memory usage)ResultsThis is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
CyclesResultsThis is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
Binary sizeThis benchmark run did not return any relevant results for this metric. Bootstrap: 662.908s -> 662.932s (0.00%) |
89: Automated pull from upstream `master` r=Dajamante a=github-actions[bot] This PR pulls the following changes from the upstream repository: * rust-lang/rust#117006 * rust-lang/rust#117511 * rust-lang/rust#117641 * rust-lang/rust#117637 * rust-lang/rust#117631 * rust-lang/rust#117516 * rust-lang/rust#117190 * rust-lang/rust#117292 * rust-lang/rust#117603 * rust-lang/rust#116988 * rust-lang/rust#117630 * rust-lang/rust#117615 * rust-lang/rust#117613 * rust-lang/rust#117592 * rust-lang/rust#117578 * rust-lang/rust#117435 * rust-lang/rust#117607 90: bump serde and serde_derive r=tshepang a=Dajamante Trying to get around the failure seen in #86 Co-authored-by: Ralf Jung <[email protected]> Co-authored-by: Esteban Küber <[email protected]> Co-authored-by: SparrowLii <[email protected]> Co-authored-by: Matthias Krüger <[email protected]> Co-authored-by: Gurinder Singh <[email protected]> Co-authored-by: Michael Goulet <[email protected]> Co-authored-by: Thom Chiovoloni <[email protected]> Co-authored-by: klensy <[email protected]> Co-authored-by: Jack Huey <[email protected]> Co-authored-by: bjorn3 <[email protected]> Co-authored-by: hkalbasi <[email protected]> Co-authored-by: bors <[email protected]> Co-authored-by: Sven Marnach <[email protected]> Co-authored-by: Rémy Rakic <[email protected]> Co-authored-by: aissata <[email protected]>
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)
Update Rust toolchain from nightly-2023-11-06 to nightly-2023-11-07 without any other source changes. This is an automatically generated pull request. If any of the CI checks fail, manual intervention is required. In such a case, review the changes at https://github.com/rust-lang/rust from rust-lang@fee5518 up to rust-lang@189d6c7. The log for this commit range is: rust-lang@189d6c71f3 Auto merge of rust-lang#117641 - matthiaskrgr:rollup-f9c12td, r=matthiaskrgr rust-lang@9efe60b1eb Rollup merge of rust-lang#117637 - lqd:trivial-bounds-with-binder-vars, r=compiler-errors rust-lang@2a1f8bccee Rollup merge of rust-lang#117631 - smarnach:error-request-doc-fix, r=ChrisDenton rust-lang@8a34fea835 Rollup merge of rust-lang#117516 - matthiaskrgr:test_effects_113375_oob, r=fee1-dead rust-lang@1683df7d3b Rollup merge of rust-lang#117190 - matthiaskrgr:test_effects_113381, r=fee1-dead rust-lang@fb61292105 Auto merge of rust-lang#117292 - estebank:issue-80446, r=davidtwco rust-lang@4b7aacaa4f Silence redundant error on typo resulting on binop rust-lang@aea82b268a Auto merge of rust-lang#117603 - HKalbasi:make-feature-additive, r=Nilstrieb rust-lang@58351ae03f add test for trivial bound not holding in `soa-derive` rust-lang@2beca157c9 check binders with bound vars for global bounds that don't hold rust-lang@b049093560 Auto merge of rust-lang#116988 - RalfJung:null, r=WaffleLapkin rust-lang@e1fcecb1b9 Auto merge of rust-lang#117630 - matthiaskrgr:rollup-v0d5p3f, r=matthiaskrgr rust-lang@3a096e96fa Documentation cleanup for core::error::Request. rust-lang@b88d62e222 Rollup merge of rust-lang#117615 - bjorn3:misc_changes, r=davidtwco rust-lang@ec35c03143 Rollup merge of rust-lang#117613 - jackh726:vacation, r=compiler-errors rust-lang@60dca87cff Rollup merge of rust-lang#117592 - thomcc:env-span-wrong, r=davidtwco rust-lang@6bf2fb3679 Auto merge of rust-lang#117578 - compiler-errors:derive-encode-in-rustc_type_ir, r=davidtwco rust-lang@f9b644636f Auto merge of rust-lang#117435 - SparrowLii:nightly_parallel, r=oli-obk,davidtwco rust-lang@fcca978aa0 Auto merge of rust-lang#117607 - klensy:clang-17.0.4, r=Mark-Simulacrum rust-lang@152a4e90d1 Auto merge of rust-lang#117585 - dnbln:feat/move-kw-span, r=cjgillot rust-lang@f2a40e99ff use portable AtomicU64 for powerPC and MIPS rust-lang@7a892ab8d8 Auto merge of rust-lang#117576 - the8472:fix-io-copy-vec, r=Mark-Simulacrum rust-lang@c8a25eddfe Make the randomize feature of rustc_abi additive rust-lang@ec29a02071 Update doc comment for CodegenBackend::link rust-lang@ba82056a14 Use the actual computed crate name for -Zprint-vtable-sizes rust-lang@1a1b10fa63 Don't steal the parse query when using --pretty rust-lang@6e33e89337 Remove from vacation and compiler review group rust-lang@38ff91c453 bump clang version for dist-x86_64-linux from 17.0.2 to 17.0.4 rust-lang@86fca873ba Use the correct span when emitting the `env!` result rust-lang@c077147200 fix clippy author and failing test rust-lang@876f698790 Add the vis.visit_capture_by() in noop_visit_expr rust-lang@54ce0346c0 add `fn visit_capture_by` to MutVisitor and fix pprust-expr-roundtrip.rs rust-lang@df85b28b72 fixes for rustfmt + ast visitor rust-lang@a6b41aa6ba fmt rust-lang@241a654c07 Fix remaining uses of `CaptureBy::Value` rust-lang@8de489918b feat(hir): Store the `Span` of the `move` keyword rust-lang@bee7b5889e Derive TyEncodable/TyDecodable implementations that are parameterized over interner rust-lang@78aa5e511c detect EOF earlier rust-lang@8d8f06b277 avoid excessive initialization when copying to a Vec rust-lang@666cad9a5f add test for rust-lang#113375 rust-lang@384f7382ba add test for rust-lang#113381 rust-lang@248dd14fa5 update config.example.toml rust-lang@bf5fb7614b update bootstrap change history rust-lang@ab8101d019 enable parallel rustc in nightly builds rust-lang@231f93524d Detect misparsed binop caused by missing semi rust-lang@98d54da1ee document that the null pointer has the 0 address --------- Co-authored-by: celinval <[email protected]> Co-authored-by: Zyad Hassan <[email protected]> Co-authored-by: Zyad Hassan <[email protected]>
Fixes #116895
Will need t-lang FCP, but I think this is fairly uncontroversial -- there's probably already tons of code out there that relies on this.