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Allow casting mut array ref to mut ptr #81479
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r? @lcnr (rust-highfive has picked a reviewer for you, use r? to override) |
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LGTM
we don't have tests for &[T; N] as *mut T
and &mut [T; N] as *const T
afaik. Both of these should error. Can you add them as well?
Nominating for Don't think this is controversial but still needs some |
Thanks for the quick review.
Should I do it in the same test file, or in a different file? |
Shouldn't |
🤷 don't care, whatever you prefer
we do allow it for |
Ah, sorry, you're right. I'm confused.. I think we could allow it. I'll wait for the lang team's feedback. |
@lcnr just out of curiosity, when is this going to be discussed? |
the lang team meeting takes place every tuesday, so in 3 days |
Any news from the meeting, @lcnr ? |
I found the meeting notes: https://hackmd.io/_-pJa1UxTE6qO1JolgNVRQ I guess there wasn't time to discuss this PR. |
We discussed this in the meeting today and decided that we approve of this PR. =) Merge away! |
Thanks lang team for considering this. I updated the PR:
@lcnr I think this is ready for merging now. |
@osa1 do we already have a test checking that if/once that test exists r=me |
I'm guessing you meant "&[T; N] as *mut T"? I added tests for that now. |
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We now allow two new casts: - mut array reference to mut ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *mut usize; We allow casting const array references to const pointers so not allowing mut references to mut pointers was inconsistent. - mut array reference to const ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *const usize; This was similarly inconsistent as we allow casting mut references to const pointers. Existing test 'vector-cast-weirdness' updated to test both cases. Fixes rust-lang#24151
Something I was wondering was whether the language reference, or some other documentation, would need to be updated. I couldn't find an obvious place when looking though. cc @rust-lang/lang-docs |
Allow casting mut array ref to mut ptr Allow casting mut array ref to mut ptr We now allow two new casts: - mut array reference to mut ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *mut usize; We allow casting const array references to const pointers so not allowing mut references to mut pointers was inconsistent. - mut array reference to const ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *const usize; This was similarly inconsistent as we allow casting mut references to const pointers. Existing test 'vector-cast-weirdness' updated to test both cases. Fixes rust-lang#24151
⌛ Testing commit d64b749 with merge 663d3127eb8812c66293464cf01bb7a2e5cf3763... |
💥 Test timed out |
probably a spurious error @bors retry |
Allow casting mut array ref to mut ptr Allow casting mut array ref to mut ptr We now allow two new casts: - mut array reference to mut ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *mut usize; We allow casting const array references to const pointers so not allowing mut references to mut pointers was inconsistent. - mut array reference to const ptr. Example: let mut x: [usize; 2] = [0, 0]; let p = &mut x as *const usize; This was similarly inconsistent as we allow casting mut references to const pointers. Existing test 'vector-cast-weirdness' updated to test both cases. Fixes rust-lang#24151
Rollup of 10 pull requests Successful merges: - rust-lang#79775 (Fix injected errors when running doctests on a crate named after a keyword) - rust-lang#81012 (Stabilize the partition_point feature) - rust-lang#81479 (Allow casting mut array ref to mut ptr) - rust-lang#81506 (HWAddressSanitizer support) - rust-lang#81741 (Increment `self.index` before calling `Iterator::self.a.__iterator_ge…) - rust-lang#81850 (use RWlock when accessing os::env) - rust-lang#81911 (GAT/const_generics: Allow with_opt_const_param to return GAT param def_id) - rust-lang#82022 (Push a `char` instead of a `str` with len one into a String) - rust-lang#82023 (Remove unnecessary lint allow attrs on example) - rust-lang#82030 (Use `Iterator::all` instead of open-coding it) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
it might make sense to mention this in the rel notes, not sure 🤔 |
It's a change in the language, so yes. |
- Add reference-to-pointer casts - Update array-to-pointer casts for [rust#81479][1] [1]: rust-lang/rust#81479
Package changes: * bump bootstraps to 1.51.0. * adjust patches and cargo checksums as required * 1.51 failed to build natively on 32-bit armv7, there is hope that this is fixed with 1.52. (1.51 can be built with netbsd32 emulation on a aarch64 system). Upsteream changes: Version 1.52.0 (2021-05-06) ============================ Language -------- - [Added the `unsafe_op_in_unsafe_fn` lint, which checks whether the unsafe code in an `unsafe fn` is wrapped in a `unsafe` block.][79208] This lint is allowed by default, and may become a warning or hard error in a future edition. - [You can now cast mutable references to arrays to a pointer of the same type as the element.][81479] Compiler -------- - [Upgraded the default LLVM to LLVM 12.][81451] Added tier 3\* support for the following targets. - [`s390x-unknown-linux-musl`][82166] - [`riscv32gc-unknown-linux-musl` & `riscv64gc-unknown-linux-musl`][82202] - [`powerpc-unknown-openbsd`][82733] \* Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [`OsString` now implements `Extend` and `FromIterator`.][82121] - [`cmp::Reverse` now has `#[repr(transparent)]` representation.][81879] - [`Arc<impl Error>` now implements `error::Error`.][80553] - [All integer division and remainder operations are now `const`.][80962] Stabilised APIs ------------- - [`Arguments::as_str`] - [`char::MAX`] - [`char::REPLACEMENT_CHARACTER`] - [`char::UNICODE_VERSION`] - [`char::decode_utf16`] - [`char::from_digit`] - [`char::from_u32_unchecked`] - [`char::from_u32`] - [`slice::partition_point`] - [`str::rsplit_once`] - [`str::split_once`] The following previously stable APIs are now `const`. - [`char::len_utf8`] - [`char::len_utf16`] - [`char::to_ascii_uppercase`] - [`char::to_ascii_lowercase`] - [`char::eq_ignore_ascii_case`] - [`u8::to_ascii_uppercase`] - [`u8::to_ascii_lowercase`] - [`u8::eq_ignore_ascii_case`] Rustdoc ------- - [Rustdoc lints are now treated as a tool lint, meaning that lints are now prefixed with `rustdoc::` (e.g. `#[warn(rustdoc::non_autolinks)]`).][80527] Using the old style is still allowed, and will become a warning in a future release. - [Rustdoc now supports argument files.][82261] - [Rustdoc now generates smart punctuation for documentation.][79423] - [You can now use "task lists" in Rustdoc Markdown.][81766] E.g. ```markdown - [x] Complete - [ ] Todo ``` Misc ---- - [You can now pass multiple filters to tests.][81356] E.g. `cargo test -- foo bar` will run all tests that match `foo` and `bar`. - [Rustup now distributes PDB symbols for the `std` library on Windows, allowing you to see `std` symbols when debugging.][82218] 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. - [Check the result cache before the DepGraph when ensuring queries][81855] - [Try fast_reject::simplify_type in coherence before doing full check][81744] - [Only store a LocalDefId in some HIR nodes][81611] - [Store HIR attributes in a side table][79519] Compatibility Notes ------------------- - [Cargo build scripts are now forbidden from setting `RUSTC_BOOTSTRAP`.] [cargo/9181] - [Removed support for the `x86_64-rumprun-netbsd` target.][82594] - [Deprecated the `x86_64-sun-solaris` target in favor of `x86_64-pc-solaris`.] [82216] - [Rustdoc now only accepts `,`, ` `, and `\t` as delimiters for specifying languages in code blocks.][78429] - [Rustc now catches more cases of `pub_use_of_private_extern_crate`][80763] - [Changes in how proc macros handle whitespace may lead to panics when used with older `proc-macro-hack` versions. A `cargo update` should be sufficient to fix this in all cases.][84136] [84136]: rust-lang/rust#84136 [80763]: rust-lang/rust#80763 [82166]: rust-lang/rust#82166 [82121]: rust-lang/rust#82121 [81879]: rust-lang/rust#81879 [82261]: rust-lang/rust#82261 [82218]: rust-lang/rust#82218 [82216]: rust-lang/rust#82216 [82202]: rust-lang/rust#82202 [81855]: rust-lang/rust#81855 [81766]: rust-lang/rust#81766 [81744]: rust-lang/rust#81744 [81611]: rust-lang/rust#81611 [81479]: rust-lang/rust#81479 [81451]: rust-lang/rust#81451 [81356]: rust-lang/rust#81356 [80962]: rust-lang/rust#80962 [80553]: rust-lang/rust#80553 [80527]: rust-lang/rust#80527 [79519]: rust-lang/rust#79519 [79423]: rust-lang/rust#79423 [79208]: rust-lang/rust#79208 [78429]: rust-lang/rust#78429 [82733]: rust-lang/rust#82733 [82594]: rust-lang/rust#82594 [cargo/9181]: rust-lang/cargo#9181 [`char::MAX`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.MAX [`char::REPLACEMENT_CHARACTER`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.REPLACEMENT_CHARACTER [`char::UNICODE_VERSION`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.UNICODE_VERSION [`char::decode_utf16`]: https://doc.rust-lang.org/std/primitive.char.html#method.decode_utf16 [`char::from_u32`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_u32 [`char::from_u32_unchecked`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_u32_unchecked [`char::from_digit`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_digit [`Peekable::next_if`]: https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if [`Peekable::next_if_eq`]: https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_eq [`Arguments::as_str`]: https://doc.rust-lang.org/stable/std/fmt/struct.Arguments.html#method.as_str [`str::split_once`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.split_once [`str::rsplit_once`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.rsplit_once [`slice::partition_point`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.partition_point [`char::len_utf8`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.len_utf8 [`char::len_utf16`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.len_utf16 [`char::to_ascii_uppercase`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_ascii_uppercase [`char::to_ascii_lowercase`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_ascii_lowercase [`char::eq_ignore_ascii_case`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.eq_ignore_ascii_case [`u8::to_ascii_uppercase`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_ascii_uppercase [`u8::to_ascii_lowercase`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_ascii_lowercase [`u8::eq_ignore_ascii_case`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.eq_ignore_ascii_case
Pkgsrc changes: * Bump bootstrap kit version to 1.51.0. * Adjust patches as needed. * Update checksum adjustments. * Fix syntax error in commands adjusting libserde_derive for Darwin Upstream changes: Version 1.52.1 (2021-05-10) ============================ This release disables incremental compilation, unless the user has explicitly opted in via the newly added RUSTC_FORCE_INCREMENTAL=1 environment variable. This is due to the widespread, and frequently occuring, breakage encountered by Rust users due to newly enabled incremental verification in 1.52.0. Notably, Rust users **should** upgrade to 1.52.0 or 1.52.1: the bugs that are detected by newly added incremental verification are still present in past stable versions, and are not yet fixed on any channel. These bugs can lead to miscompilation of Rust binaries. These problems only affect incremental builds, so release builds with Cargo should not be affected unless the user has explicitly opted into incremental. Debug and check builds are affected. See [84970] for more details. [84970]: rust-lang/rust#84970 Version 1.52.0 (2021-05-06) ============================ Language -------- - [Added the `unsafe_op_in_unsafe_fn` lint, which checks whether the unsafe code in an `unsafe fn` is wrapped in a `unsafe` block.][79208] This lint is allowed by default, and may become a warning or hard error in a future edition. - [You can now cast mutable references to arrays to a pointer of the same type as the element.][81479] Compiler -------- - [Upgraded the default LLVM to LLVM 12.][81451] Added tier 3\* support for the following targets. - [`s390x-unknown-linux-musl`][82166] - [`riscv32gc-unknown-linux-musl` & `riscv64gc-unknown-linux-musl`][82202] - [`powerpc-unknown-openbsd`][82733] \* Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [`OsString` now implements `Extend` and `FromIterator`.][82121] - [`cmp::Reverse` now has `#[repr(transparent)]` representation.][81879] - [`Arc<impl Error>` now implements `error::Error`.][80553] - [All integer division and remainder operations are now `const`.][80962] Stabilised APIs ------------- - [`Arguments::as_str`] - [`char::MAX`] - [`char::REPLACEMENT_CHARACTER`] - [`char::UNICODE_VERSION`] - [`char::decode_utf16`] - [`char::from_digit`] - [`char::from_u32_unchecked`] - [`char::from_u32`] - [`slice::partition_point`] - [`str::rsplit_once`] - [`str::split_once`] The following previously stable APIs are now `const`. - [`char::len_utf8`] - [`char::len_utf16`] - [`char::to_ascii_uppercase`] - [`char::to_ascii_lowercase`] - [`char::eq_ignore_ascii_case`] - [`u8::to_ascii_uppercase`] - [`u8::to_ascii_lowercase`] - [`u8::eq_ignore_ascii_case`] Rustdoc ------- - [Rustdoc lints are now treated as a tool lint, meaning that lints are now prefixed with `rustdoc::` (e.g. `#[warn(rustdoc::non_autolinks)]`).][80527] Using the old style is still allowed, and will become a warning in a future release. - [Rustdoc now supports argument files.][82261] - [Rustdoc now generates smart punctuation for documentation.][79423] - [You can now use "task lists" in Rustdoc Markdown.][81766] E.g. ```markdown - [x] Complete - [ ] Todo ``` Misc ---- - [You can now pass multiple filters to tests.][81356] E.g. `cargo test -- foo bar` will run all tests that match `foo` and `bar`. - [Rustup now distributes PDB symbols for the `std` library on Windows, allowing you to see `std` symbols when debugging.][82218] 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. - [Check the result cache before the DepGraph when ensuring queries][81855] - [Try fast_reject::simplify_type in coherence before doing full check][81744] - [Only store a LocalDefId in some HIR nodes][81611] - [Store HIR attributes in a side table][79519] Compatibility Notes ------------------- - [Cargo build scripts are now forbidden from setting `RUSTC_BOOTSTRAP`.][cargo/9181] - [Removed support for the `x86_64-rumprun-netbsd` target.][82594] - [Deprecated the `x86_64-sun-solaris` target in favor of `x86_64-pc-solaris`.][82216] - [Rustdoc now only accepts `,`, ` `, and `\t` as delimiters for specifying languages in code blocks.][78429] - [Rustc now catches more cases of `pub_use_of_private_extern_crate`][80763] - [Changes in how proc macros handle whitespace may lead to panics when used with older `proc-macro-hack` versions. A `cargo update` should be sufficient to fix this in all cases.][84136] [84136]: rust-lang/rust#84136 [80763]: rust-lang/rust#80763 [82166]: rust-lang/rust#82166 [82121]: rust-lang/rust#82121 [81879]: rust-lang/rust#81879 [82261]: rust-lang/rust#82261 [82218]: rust-lang/rust#82218 [82216]: rust-lang/rust#82216 [82202]: rust-lang/rust#82202 [81855]: rust-lang/rust#81855 [81766]: rust-lang/rust#81766 [81744]: rust-lang/rust#81744 [81611]: rust-lang/rust#81611 [81479]: rust-lang/rust#81479 [81451]: rust-lang/rust#81451 [81356]: rust-lang/rust#81356 [80962]: rust-lang/rust#80962 [80553]: rust-lang/rust#80553 [80527]: rust-lang/rust#80527 [79519]: rust-lang/rust#79519 [79423]: rust-lang/rust#79423 [79208]: rust-lang/rust#79208 [78429]: rust-lang/rust#78429 [82733]: rust-lang/rust#82733 [82594]: rust-lang/rust#82594 [cargo/9181]: rust-lang/cargo#9181 [`char::MAX`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.MAX [`char::REPLACEMENT_CHARACTER`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.REPLACEMENT_CHARACTER [`char::UNICODE_VERSION`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.UNICODE_VERSION [`char::decode_utf16`]: https://doc.rust-lang.org/std/primitive.char.html#method.decode_utf16 [`char::from_u32`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_u32 [`char::from_u32_unchecked`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_u32_unchecked [`char::from_digit`]: https://doc.rust-lang.org/std/primitive.char.html#method.from_digit [`Peekable::next_if`]: https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if [`Peekable::next_if_eq`]: https://doc.rust-lang.org/stable/std/iter/struct.Peekable.html#method.next_if_eq [`Arguments::as_str`]: https://doc.rust-lang.org/stable/std/fmt/struct.Arguments.html#method.as_str [`str::split_once`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.split_once [`str::rsplit_once`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.rsplit_once [`slice::partition_point`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.partition_point [`char::len_utf8`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.len_utf8 [`char::len_utf16`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.len_utf16 [`char::to_ascii_uppercase`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_ascii_uppercase [`char::to_ascii_lowercase`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_ascii_lowercase [`char::eq_ignore_ascii_case`]: https://doc.rust-lang.org/stable/std/primitive.char.html#method.eq_ignore_ascii_case [`u8::to_ascii_uppercase`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_ascii_uppercase [`u8::to_ascii_lowercase`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_ascii_lowercase [`u8::eq_ignore_ascii_case`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.eq_ignore_ascii_case
Note: |
Allow casting mut array ref to mut ptr
We now allow two new casts:
mut array reference to mut ptr. Example:
We allow casting const array references to const pointers so not
allowing mut references to mut pointers was inconsistent.
mut array reference to const ptr. Example:
This was similarly inconsistent as we allow casting mut references to
const pointers.
Existing test 'vector-cast-weirdness' updated to test both cases.
Fixes #24151