guarantee that char and u32 are ABI-compatible #118032
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(rustbot has picked a reviewer for you, use r? to override) |
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Some changes occurred to the CTFE / Miri engine cc @rust-lang/miri The Miri subtree was changed cc @rust-lang/miri |
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Cc @rust-lang/opsem |
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We discussed this in the T-Lang triage meeting today. There was some discussion about whether it'd ever be reasonable to want to do something more optimal here -- maybe passing three But as I understood it, the takeaway was that those were considered too unusual to be worth doing, vs the simple rule that people are probably already expecting to be the case (given the size+align match), so let's get confirmation of that: @rfcbot fcp merge |
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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. |
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🔔 This is now entering its final comment period, as per the review above. 🔔 |
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Hey @rust-lang/project-exploit-mitigations , is it okay to guarantee that |
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@pnkfelix thanks for pinging us! I've a few questions so I have a bit more context:
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Yes.
This is a guarantee for all our ABIs. This is similar to how we e.g. already guarantee that
Yes. I am not sure if we are currently officially documenting anywhere that |
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Thank you for all the information, @RalfJung! Np, I think this should be added to the CFI integer normalization option then. Just let me know by when it needs to be done. |
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Well this PR will hopefully land in around 10 days. :) |
Adds char to CFI integer normalization to conform to rust-lang#118032 for cross-language CFI support.
…s-118032, r=compiler-errors CFI: Add char to CFI integer normalization Adds char to CFI integer normalization to conform to rust-lang#118032 for cross-language CFI support.
Rollup merge of rust-lang#118719 - rcvalle:rust-cfi-normalize-integers-118032, r=compiler-errors CFI: Add char to CFI integer normalization Adds char to CFI integer normalization to conform to rust-lang#118032 for cross-language CFI support.
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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. |
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@Mark-Simulacrum this is back in your court for review now. |
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@bors r+ |
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☀️ Test successful - checks-actions |
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ping @rcvalle directly as requested in #118032 (comment) |
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Finished benchmarking commit (e299752): comparison URL. Overall result: ❌ regressions - no action needed@rustbot label: -perf-regression Instruction countThis is a highly reliable metric that was used to determine the overall result at the top of this comment.
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.
CyclesThis benchmark run did not return any relevant results for this metric. Binary sizeThis benchmark run did not return any relevant results for this metric. Bootstrap: 668.219s -> 668.003s (-0.03%) |
Pkgsrc changes: * Adapt checksums and patches. Upstream chnages: Version 1.76.0 (2024-02-08) ========================== Language -------- - [Document Rust ABI compatibility between various types] (rust-lang/rust#115476) - [Also: guarantee that char and u32 are ABI-compatible] (rust-lang/rust#118032) - [Warn against ambiguous wide pointer comparisons] (rust-lang/rust#117758) Compiler -------- - [Lint pinned `#[must_use]` pointers (in particular, `Box<T>` where `T` is `#[must_use]`) in `unused_must_use`.] (rust-lang/rust#118054) - [Soundness fix: fix computing the offset of an unsized field in a packed struct] (rust-lang/rust#118540) - [Soundness fix: fix dynamic size/align computation logic for packed types with dyn Trait tail] (rust-lang/rust#118538) - [Add `$message_type` field to distinguish json diagnostic outputs] (rust-lang/rust#115691) - [Enable Rust to use the EHCont security feature of Windows] (rust-lang/rust#118013) - [Add tier 3 {x86_64,i686}-win7-windows-msvc targets] (rust-lang/rust#118150) - [Add tier 3 aarch64-apple-watchos target] (rust-lang/rust#119074) - [Add tier 3 arm64e-apple-ios & arm64e-apple-darwin targets] (rust-lang/rust#115526) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Add a column number to `dbg!()`] (rust-lang/rust#114962) - [Add `std::hash::{DefaultHasher, RandomState}` exports] (rust-lang/rust#115694) - [Fix rounding issue with exponents in fmt] (rust-lang/rust#116301) - [Add T: ?Sized to `RwLockReadGuard` and `RwLockWriteGuard`'s Debug impls.] (rust-lang/rust#117138) - [Windows: Allow `File::create` to work on hidden files] (rust-lang/rust#116438) Stabilized APIs --------------- - [`Arc::unwrap_or_clone`] (https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.unwrap_or_clone) - [`Rc::unwrap_or_clone`] (https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.unwrap_or_clone) - [`Result::inspect`] (https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.inspect) - [`Result::inspect_err`] (https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.inspect_err) - [`Option::inspect`] (https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.inspect) - [`type_name_of_val`] (https://doc.rust-lang.org/stable/std/any/fn.type_name_of_val.html) - [`std::hash::{DefaultHasher, RandomState}`] (https://doc.rust-lang.org/stable/std/hash/index.html#structs) These were previously available only through `std::collections::hash_map`. - [`ptr::{from_ref, from_mut}`] (https://doc.rust-lang.org/stable/std/ptr/fn.from_ref.html) - [`ptr::addr_eq`](https://doc.rust-lang.org/stable/std/ptr/fn.addr_eq.html) Cargo ----- See [Cargo release notes] (https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-176-2024-02-08). Rustdoc ------- - [Don't merge cfg and doc(cfg) attributes fo B9FE r re-exports] (rust-lang/rust#113091) - [rustdoc: allow resizing the sidebar / hiding the top bar] (rust-lang/rust#115660) - [rustdoc-search: add support for traits and associated types] (rust-lang/rust#116085) - [rustdoc: Add highlighting for comments in items declaration] (rust-lang/rust#117869) Compatibility Notes ------------------- - [Add allow-by-default lint for unit bindings] (rust-lang/rust#112380) This is expected to be upgraded to a warning by default in a future Rust release. Some macros emit bindings with type `()` with user-provided spans, which means that this lint will warn for user code. - [Remove x86_64-sun-solaris target.] (rust-lang/rust#118091) - [Remove asmjs-unknown-emscripten target] (rust-lang/rust#117338) - [Report errors in jobserver inherited through environment variables] (rust-lang/rust#113730) This [may warn](rust-lang/rust#120515) on benign problems too. - [Update the minimum external LLVM to 16.] (rust-lang/rust#117947) - [Improve `print_tts`](rust-lang/rust#114571) This change can break some naive manual parsing of token trees in proc macro code which expect a particular structure after `.to_string()`, rather than just arbitrary Rust code. - [Make `IMPLIED_BOUNDS_ENTAILMENT` into a hard error from a lint] (rust-lang/rust#117984) - [Vec's allocation behavior was changed when collecting some iterators] (rust-lang/rust#110353) Allocation behavior is currently not specified, nevertheless changes can be surprising. See [`impl FromIterator for Vec`] (https://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#impl-FromIterator%3CT%3E-for-Vec%3CT%3E) for more details. - [Properly reject `default` on free const items] (rust-lang/rust#117818)
Adds char to CFI integer normalization to conform to rust-lang#118032 for cross-language CFI support.
In #116894 we added a guarantee that
charhas the same alignment asu32, 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,charandu32are completely equivalent.This is a new stable guarantee, so it will need t-lang approval.