regression: target_feature no longer permitted in some places #78143

Mark-Simulacrum · 2020-10-20T14:31:25Z

Likely caused by #71205

Mark-Simulacrum · 2020-10-20T14:31:58Z

I suspect we'll call this won't fix but I have nominated it for T-lang to get it on the agenda for next triage meeting.

nikomatsakis · 2020-10-26T19:43:13Z

Summary:

unused #[target_feature] attributes appearing in surprising places because of rustc: fix check_attr() for methods, closures and foreign functions #71205, places that have no effect
another case where we have to think about our regression policy
seems clear that the "detect if attributes are used" part of the compiler winds up incorrectly thinking that things are used fairly regularly
given limited impact and the fact that it's clearly a bug, we're inclined to let this change go forward as a bug fix (we can revisit if/when we receive more complaints)

pnkfelix · 2020-11-06T15:13:44Z

assigning to mark to ensure that release notes include the note about this being a bug fix with limited impact.

Mark-Simulacrum · 2020-11-07T18:44:00Z

https://github.com/rust-lang/rust/pull/78364/files#diff-4a00447b47c36ebd3ded77321deff288e424f4605496ee1199fc9953a20f4473R80 (though that link may go stale). Closing.

Clean up some of the pkgsrc Makefile, there's still lots in here that should just be deleted though. Switch SunOS to the illumos bootstrap by default. Version 1.48.0 (2020-11-19) ========================== Language -------- - [The `unsafe` keyword is now syntactically permitted on modules.][75857] This is still rejected *semantically*, but can now be parsed by procedural macros. Compiler -------- - [Stabilised the `-C link-self-contained=<yes|no>` compiler flag.][76158] This tells `rustc` whether to link its own C runtime and libraries or to rely on a external linker to find them. (Supported only on `windows-gnu`, `linux-musl`, and `wasi` platforms.) - [You can now use `-C target-feature=+crt-static` on `linux-gnu` targets.][77386] Note: If you're using cargo you must explicitly pass the `--target` flag. - [Added tier 2\* support for `aarch64-unknown-linux-musl`.][76420] \* Refer to Rust's [platform support page][forge-platform-support] for more information on Rust's tiered platform support. Libraries --------- - [`io::Write` is now implemented for `&ChildStdin` `&Sink`, `&Stdout`, and `&Stderr`.][76275] - [All arrays of any length now implement `TryFrom<Vec<T>>`.][76310] - [The `matches!` macro now supports having a trailing comma.][74880] - [`Vec<A>` now implements `PartialEq<[B]>` where `A: PartialEq<B>`.][74194] - [The `RefCell::{replace, replace_with, clone}` methods now all use `#[track_caller]`.][77055] Stabilized APIs --------------- - [`slice::as_ptr_range`] - [`slice::as_mut_ptr_range`] - [`VecDeque::make_contiguous`] - [`future::pending`] - [`future::ready`] The following previously stable methods are now `const fn`'s: - [`Option::is_some`] - [`Option::is_none`] - [`Option::as_ref`] - [`Result::is_ok`] - [`Result::is_err`] - [`Result::as_ref`] - [`Ordering::reverse`] - [`Ordering::then`] Cargo ----- Rustdoc ------- - [You can now link to items in `rustdoc` using the intra-doc link syntax.][74430] E.g. ``/// Uses [`std::future`]`` will automatically generate a link to `std::future`'s documentation. See ["Linking to items by name"][intradoc-links] for more information. - [You can now specify `#[doc(alias = "<alias>")]` on items to add search aliases when searching through `rustdoc`'s UI.][75740] Compatibility Notes ------------------- - [Promotion of references to `'static` lifetime inside `const fn` now follows the same rules as inside a `fn` body.][75502] In particular, `&foo()` will not be promoted to `'static` lifetime any more inside `const fn`s. - [Associated type bindings on trait objects are now verified to meet the bounds declared on the trait when checking that they implement the trait.][27675] - [When trait bounds on associated types or opaque types are ambiguous, the compiler no longer makes an arbitrary choice on which bound to use.][54121] - [Fixed recursive nonterminals not being expanded in macros during pretty-print/reparse check.][77153] This may cause errors if your macro wasn't correctly handling recursive nonterminal tokens. - [`&mut` references to non zero-sized types are no longer promoted.][75585] - [`rustc` will now warn if you use attributes like `#[link_name]` or `#[cold]` in places where they have no effect.][73461] - [Updated `_mm256_extract_epi8` and `_mm256_extract_epi16` signatures in `arch::{x86, x86_64}` to return `i32` to match the vendor signatures.][73166] - [`mem::uninitialized` will now panic if any inner types inside a struct or enum disallow zero-initialization.][71274] - [`#[target_feature]` will now error if used in a place where it has no effect.][78143] - [Foreign exceptions are now caught by `catch_unwind` and will cause an abort.][70212] Note: This behaviour is not guaranteed and is still considered undefined behaviour, see the [`catch_unwind`] documentation for further information. Internal Only ------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of rustc and related tools. - [Building `rustc` from source now uses `ninja` by default over `make`.][74922] You can continue building with `make` by setting `ninja=false` in your `config.toml`. - [cg_llvm: `fewer_names` in `uncached_llvm_type`][76030] - [Made `ensure_sufficient_stack()` non-generic][76680] [78143]: rust-lang/rust#78143 [76680]: rust-lang/rust#76680 [76030]: rust-lang/rust#76030 [70212]: rust-lang/rust#70212 [27675]: rust-lang/rust#27675 [54121]: rust-lang/rust#54121 [71274]: rust-lang/rust#71274 [77386]: rust-lang/rust#77386 [77153]: rust-lang/rust#77153 [77055]: rust-lang/rust#77055 [76275]: rust-lang/rust#76275 [76310]: rust-lang/rust#76310 [76420]: rust-lang/rust#76420 [76158]: rust-lang/rust#76158 [75857]: rust-lang/rust#75857 [75585]: rust-lang/rust#75585 [75740]: rust-lang/rust#75740 [75502]: rust-lang/rust#75502 [74880]: rust-lang/rust#74880 [74922]: rust-lang/rust#74922 [74430]: rust-lang/rust#74430 [74194]: rust-lang/rust#74194 [73461]: rust-lang/rust#73461 [73166]: rust-lang/rust#73166 [intradoc-links]: https://doc.rust-lang.org/rustdoc/linking-to-items-by-name.html [`catch_unwind`]: https://doc.rust-lang.org/std/panic/fn.catch_unwind.html [`Option::is_some`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_some [`Option::is_none`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_none [`Option::as_ref`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.as_ref [`Result::is_ok`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok [`Result::is_err`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err [`Result::as_ref`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.as_ref [`Ordering::reverse`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.reverse [`Ordering::then`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then [`slice::as_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_ptr_range [`slice::as_mut_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_mut_ptr_range [`VecDeque::make_contiguous`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.make_contiguous [`future::pending`]: https://doc.rust-lang.org/std/future/fn.pending.html [`future::ready`]: https://doc.rust-lang.org/std/future/fn.ready.html

Pkgsrc changes: * Compensate for files being moved around upstream. * Introduce optional, on-by-default semi-static building of cargo, using the internal curl and openssl sources. This reduces the dynamic dependencies of cargo and therefore the rust package itself. Ref. options.mk. * The 1.47.0 bootstrap kits have been re-built with the above option turned on, so no longer depends on curl or openssl from pkgsrc and/or from earlier OS or pkgsrc versions. This should hopefully fix installation of rust with non-default PREFIX, ref. PR#54453. Upstream changes: Version 1.48.0 (2020-11-19) ========================== Language -------- - [The `unsafe` keyword is now syntactically permitted on modules.][75857] This is still rejected *semantically*, but can now be parsed by procedural macros. Compiler -------- - [Stabilised the `-C link-self-contained=<yes|no>` compiler flag.][76158] This tells `rustc` whether to link its own C runtime and libraries or to rely on a external linker to find them. (Supported only on `windows-gnu`, `linux-musl`, and `wasi` platforms.) - [You can now use `-C target-feature=+crt-static` on `linux-gnu` targets.] [77386] Note: If you're using cargo you must explicitly pass the `--target` flag. - [Added tier 2\* support for `aarch64-unknown-linux-musl`.][76420] \* Refer to Rust's [platform support page][forge-platform-support] for more information on Rust's tiered platform support. Libraries --------- - [`io::Write` is now implemented for `&ChildStdin` `&Sink`, `&Stdout`, and `&Stderr`.][76275] - [All arrays of any length now implement `TryFrom<Vec<T>>`.][76310] - [The `matches!` macro now supports having a trailing comma.][74880] - [`Vec<A>` now implements `PartialEq<[B]>` where `A: PartialEq<B>`.][74194] - [The `RefCell::{replace, replace_with, clone}` methods now all use `#[track_caller]`.][77055] Stabilized APIs --------------- - [`slice::as_ptr_range`] - [`slice::as_mut_ptr_range`] - [`VecDeque::make_contiguous`] - [`future::pending`] - [`future::ready`] The following previously stable methods are now `const fn`'s: - [`Option::is_some`] - [`Option::is_none`] - [`Option::as_ref`] - [`Result::is_ok`] - [`Result::is_err`] - [`Result::as_ref`] - [`Ordering::reverse`] - [`Ordering::then`] Cargo ----- Rustdoc ------- - [You can now link to items in `rustdoc` using the intra-doc link syntax.][74430] E.g. ``/// Uses [`std::future`]`` will automatically generate a link to `std::future`'s documentation. See ["Linking to items by name"][intradoc-links] for more information. - [You can now specify `#[doc(alias = "<alias>")]` on items to add search aliases when searching through `rustdoc`'s UI.][75740] Compatibility Notes ------------------- - [Promotion of references to `'static` lifetime inside `const fn` now follows the same rules as inside a `fn` body.][75502] In particular, `&foo()` will not be promoted to `'static` lifetime any more inside `const fn`s. - [Associated type bindings on trait objects are now verified to meet the bounds declared on the trait when checking that they implement the trait.][27675] - [When trait bounds on associated types or opaque types are ambiguous, the compiler no longer makes an arbitrary choice on which bound to use.][54121] - [Fixed recursive nonterminals not being expanded in macros during pretty-print/reparse check.][77153] This may cause errors if your macro wasn't correctly handling recursive nonterminal tokens. - [`&mut` references to non zero-sized types are no longer promoted.][75585] - [`rustc` will now warn if you use attributes like `#[link_name]` or `#[cold]` in places where they have no effect.][73461] - [Updated `_mm256_extract_epi8` and `_mm256_extract_epi16` signatures in `arch::{x86, x86_64}` to return `i32` to match the vendor signatures.][73166] - [`mem::uninitialized` will now panic if any inner types inside a struct or enum disallow zero-initialization.][71274] - [`#[target_feature]` will now error if used in a place where it has no effect.][78143] - [Foreign exceptions are now caught by `catch_unwind` and will cause an abort.][70212] Note: This behaviour is not guaranteed and is still considered undefined behaviour, see the [`catch_unwind`] documentation for further information. Internal Only ------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of rustc and related tools. - [Building `rustc` from source now uses `ninja` by default over `make`.][74922] You can continue building with `make` by setting `ninja=false` in your `config.toml`. - [cg_llvm: `fewer_names` in `uncached_llvm_type`][76030] - [Made `ensure_sufficient_stack()` non-generic][76680] [78143]: rust-lang/rust#78143 [76680]: rust-lang/rust#76680 [76030]: rust-lang/rust#76030 [70212]: rust-lang/rust#70212 [27675]: rust-lang/rust#27675 [54121]: rust-lang/rust#54121 [71274]: rust-lang/rust#71274 [77386]: rust-lang/rust#77386 [77153]: rust-lang/rust#77153 [77055]: rust-lang/rust#77055 [76275]: rust-lang/rust#76275 [76310]: rust-lang/rust#76310 [76420]: rust-lang/rust#76420 [76158]: rust-lang/rust#76158 [75857]: rust-lang/rust#75857 [75585]: rust-lang/rust#75585 [75740]: rust-lang/rust#75740 [75502]: rust-lang/rust#75502 [74880]: rust-lang/rust#74880 [74922]: rust-lang/rust#74922 [74430]: rust-lang/rust#74430 [74194]: rust-lang/rust#74194 [73461]: rust-lang/rust#73461 [73166]: rust-lang/rust#73166 [intradoc-links]: https://doc.rust-lang.org/rustdoc/linking-to-items-by-name.html [`catch_unwind`]: https://doc.rust-lang.org/std/panic/fn.catch_unwind.html [`Option::is_some`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_some [`Option::is_none`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_none [`Option::as_ref`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.as_ref [`Result::is_ok`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok [`Result::is_err`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err [`Result::as_ref`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.as_ref [`Ordering::reverse`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.reverse [`Ordering::then`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then [`slice::as_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_ptr_range [`slice::as_mut_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_mut_ptr_range [`VecDeque::make_contiguous`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.make_contiguous [`future::pending`]: https://doc.rust-lang.org/std/future/fn.pending.html [`future::ready`]: https://doc.rust-lang.org/std/future/fn.ready.html

rustbot added the I-prioritize Issue: Indicates that prioritization has been requested for this issue. label Oct 20, 2020

Mark-Simulacrum added this to the 1.48.0 milestone Oct 20, 2020

Mark-Simulacrum mentioned this issue Oct 20, 2020

Crater runs for 1.48 #77970

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apiraino removed the I-prioritize Issue: Indicates that prioritization has been requested for this issue. label Oct 21, 2020

Mark-Simulacrum mentioned this issue Oct 26, 2020

Update RELEASES.md for 1.48.0 #78364

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nikomatsakis removed the I-nominated label Oct 26, 2020

pnkfelix assigned Mark-Simulacrum Nov 6, 2020

Mark-Simulacrum closed this as completed Nov 7, 2020

hendrikhofstadt mentioned this issue Nov 25, 2020

Build breaks on Rust 1.48 solana-labs/solana#13808

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regression: target_feature no longer permitted in some places #78143

regression: target_feature no longer permitted in some places #78143

Mark-Simulacrum commented Oct 20, 2020 •

edited

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Mark-Simulacrum commented Oct 20, 2020

nikomatsakis commented Oct 26, 2020

pnkfelix commented Nov 6, 2020

Mark-Simulacrum commented Nov 7, 2020

regression: target_feature no longer permitted in some places #78143

regression: target_feature no longer permitted in some places #78143

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Mark-Simulacrum commented Oct 20, 2020 • edited Loading

Mark-Simulacrum commented Oct 20, 2020

nikomatsakis commented Oct 26, 2020

pnkfelix commented Nov 6, 2020

Mark-Simulacrum commented Nov 7, 2020

Mark-Simulacrum commented Oct 20, 2020 •

edited

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