De-duplicate and improve definition of core::ffi::c_char by arichardson · Pull Request #132975 · rust-lang/rust

arichardson · 2024-11-13T01:30:40Z

Instead of having a list of unsigned char targets for each OS, follow the logic Clang uses and instead set the value based on architecture with a special case for Darwin and Windows operating systems. This makes it easier to support new operating systems targeting Arm/AArch64 without having to modify this config statement for each new OS. The new list does not quite match Clang since I noticed a few bugs in the Clang implementation (llvm/llvm-project#115957).

Fixes #129945
Closes #131319

rustbot · 2024-11-13T01:30:50Z

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @cuviper (or someone else) some time within the next two weeks.

Please see the contribution instructions for more information. Namely, in order to ensure the minimum review times lag, PR authors and assigned reviewers should ensure that the review label (S-waiting-on-review and S-waiting-on-author) stays updated, invoking these commands when appropriate:

@rustbot author: the review is finished, PR author should check the comments and take action accordingly
@rustbot review: the author is ready for a review, this PR will be queued again in the reviewer's queue

arichardson · 2024-11-13T01:33:45Z

r? @maurer @joshtriplett

rustbot · 2024-11-13T01:33:48Z

Failed to set assignee to maurer: invalid assignee

Note: Only org members with at least the repository "read" role, users with write permissions, or people who have commented on the PR may be assigned.

beetrees · 2024-11-13T18:01:22Z

I think r? @joshtriplett should work.

maurer

Some OSes are no longer conditioned on, for example, os=nto arch=aarch64 or os=l4re, arch=x86_64 are missing.

I didn't manually verify everything, but at least l4re and x86_64 just got flipped from u8, which it appears to have been manually set to, to i8.

Can we get a summary of what changed in terms of supported target triples? I would expect disagreements with clang to be rare, but this patch looks like it accidentally changes obscure targets at a minimum. It might also be clearer what changed if we didn't have the 4-branch if statement for 2 results.

library/core/src/ffi/mod.rs

maurer · 2024-11-13T19:12:18Z

I'm pretty sure this still changes l4re-x86_64 from unsigned to signed.

beetrees · 2024-11-13T19:21:40Z

As Apple and Windows targets always use signed char, you could simplify the cfg statement further to cfg(all(not(any(windows, target_vendor = "apple")), any(/* target_arch/target_os that use unsigned char */)))

arichardson · 2024-11-13T19:25:36Z

I'm pretty sure this still changes l4re-x86_64 from unsigned to signed.

I'm trying to figure out if that value is intentional or not. It dates back to 2cf0a4a, ~~but I can't see anything in L4RE that changes the default - maybe this was actually indented to set it for aarch64?~~

arichardson · 2024-11-13T19:30:28Z

Looks like l4re should be setting this for all architectures, I spotted -funsigned-char in https://github.com/kernkonzept/mk/blob/926afa93e32e64dbdb33cf9ae724924ee1fb16e0/tool/kconfig/Makefile#L550, so that suggests it's the case for all targets. Will update to handle that.

joshtriplett · 2024-11-14T00:19:09Z

r? libs-api

tgross35 · 2024-11-15T00:29:11Z

See also an open issue about this #129945 and an open PR that this would supersede #131319 (cc @taiki-e)

I also wrote an issue requesting a test of our types against Clang at some point #133058.

arichardson · 2024-11-16T22:50:49Z

I have validated the new c_char definitions against my build of clang that has fixes for MSP430, Xtensa (although printing the builtin defines fails with error: unknown target triple 'xtensa-unknown-none-elf'), and CSKY (which fails with version 'abiv2' in target triple 'csky-unknown-linux-gnuabiv2' is invalid).

Unlike #131319 this PR does not have links to all the ABI docs, but it does have a correct definition for l4re (which clang does not support and treats as unknown OS).

taiki-e · 2024-11-19T03:44:25Z

As for L4Re:
I think L4Re code you are linking is config when building kernel. IIUC, userland uses signed for x86_64 and unsigned for aarch64 by default (i.e., same as ELF ABI's default).

$ ./toolchain-l4re-x86_64-gcc-14/bin/x86_64-l4re-gcc -E -dM -x c /dev/null | grep -F __CHAR_
#define __CHAR_BIT__ 8

$ ./toolchain-l4re-arm64-gcc-14/bin/aarch64-l4re-gcc -E -dM -x c /dev/null | grep -F __CHAR_
#define __CHAR_BIT__ 8
#define __CHAR_UNSIGNED__ 1

({x86_64,aarch64}-l4re-gcc are from https://l4re.org/download/snapshots/toolchain/.)

As for Xtensa:
Section 2.17.1 "Data Types and Alignment" of Xtensa LX Microprocessor Overview handbook https://loboris.eu/ESP32/Xtensa_lx%20Overview%20handbook.pdf says "char type is unsigned by default".

However, it appears that Xtensa has multiple ABIs. (Section 1.4 "Calling convention" of Overview of Xtensa ISA https://dl.espressif.com/github_assets/espressif/xtensa-isa-doc/releases/download/latest/Xtensa.pdf)
(I have not checked whether the defaults are consistent among those ABIs or not -- this is why my PR has done nothing about Xtensa.)

As noted in rust-lang#132975 (comment), the default for userland apps is to follow the architecture defaults, the -funsigned-char flag only applies to kernel builds.

arichardson · 2024-12-04T17:44:49Z

Rebased and fixed the l4re issue.

As for L4Re: I think L4Re code you are linking is config when building kernel. IIUC, userland uses signed for x86_64 and unsigned for aarch64 by default (i.e., same as ELF ABI's default).
$ ./toolchain-l4re-x86_64-gcc-14/bin/x86_64-l4re-gcc -E -dM -x c /dev/null | grep -F __CHAR_
#define __CHAR_BIT__ 8

$ ./toolchain-l4re-arm64-gcc-14/bin/aarch64-l4re-gcc -E -dM -x c /dev/null | grep -F __CHAR_
#define __CHAR_BIT__ 8
#define __CHAR_UNSIGNED__ 1
({x86_64,aarch64}-l4re-gcc are from https://l4re.org/download/snapshots/toolchain/.)

Thanks for checking this, I've updated the change to remove l4re from the list. I've done this as a separate commit in case this needs to be reverted in the future.

As for Xtensa: Section 2.17.1 "Data Types and Alignment" of Xtensa LX Microprocessor Overview handbook https://loboris.eu/ESP32/Xtensa_lx%20Overview%20handbook.pdf says "char type is unsigned by default".

However, it appears that Xtensa has multiple ABIs. (Section 1.4 "Calling convention" of Overview of Xtensa ISA https://dl.espressif.com/github_assets/espressif/xtensa-isa-doc/releases/download/latest/Xtensa.pdf) (I have not checked whether the defaults are consistent among those ABIs or not -- this is why my PR has done nothing about Xtensa.)

Regarding Xtensa, my Clang change to make it unsigned by default was approved by Xtensa developers and has been merged now: llvm/llvm-project#115967.

Update comments and sort target_arch in c_char_definition Follow-up to rust-lang#132975. - Clang's wrong default on MSP430 has been fixed in llvm/llvm-project#115964, and will be included in LLVM 20, which will be used soon. - Add a reference on Xtensa's default (from rust-lang#132975 (comment)). - Fix link for Windows's default. - Add a link to the discussion on L4Re (rust-lang#132975 (comment)) - Sort `target_arch`. (now match with `target_arch`s in comments) r? `@tgross35`

Rollup merge of rust-lang#136173 - taiki-e:c-char, r=tgross35 Update comments and sort target_arch in c_char_definition Follow-up to rust-lang#132975. - Clang's wrong default on MSP430 has been fixed in llvm/llvm-project#115964, and will be included in LLVM 20, which will be used soon. - Add a reference on Xtensa's default (from rust-lang#132975 (comment)). - Fix link for Windows's default. - Add a link to the discussion on L4Re (rust-lang#132975 (comment)) - Sort `target_arch`. (now match with `target_arch`s in comments) r? `@tgross35`

As noted in rust-lang#132975 (comment), the default for userland apps is to follow the architecture defaults, the -funsigned-char flag only applies to kernel builds.

Pkgsrc changes relative to rust184: * patch reorganization to deal with new version of upstream vendored crates, checksum updates. Version 1.85.0 (2025-02-20) ========================== Language -------- - [The 2024 Edition is now stable.] (rust-lang/rust#133349) See [the edition guide] (https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html) for more details. - [Stabilize async closures] (rust-lang/rust#132706) See [RFC 3668] (https://rust-lang.github.io/rfcs/3668-async-closures.html) for more details. - [Stabilize `#[diagnostic::do_not_recommend]`] (rust-lang/rust#132056) - [Add `unpredictable_function_pointer_comparisons` lint to warn against function pointer comparisons] (rust-lang/rust#118833) - [Lint on combining `#[no_mangle]` and `#[export_name]` attributes.] (rust-lang/rust#131558) Compiler -------- - [The unstable flag `-Zpolymorphize` has been removed] (rust-lang/rust#133883), see rust-lang/compiler-team#810 for some background. Platform Support ---------------- - [Promote `powerpc64le-unknown-linux-musl` to tier 2 with host tools] (rust-lang/rust#133801) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Panics in the standard library now have a leading `library/` in their path] (rust-lang/rust#132390) - [`std::env::home_dir()` on Windows now ignores the non-standard `$HOME` environment variable] (rust-lang/rust#132515) It will be un-deprecated in a subsequent release. - [Add `AsyncFn*` to the prelude in all editions.] (rust-lang/rust#132611) Stabilized APIs --------------- - [`BuildHasherDefault::new`] (https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new) - [`ptr::fn_addr_eq`] (https://doc.rust-lang.org/std/ptr/fn.fn_addr_eq.html) - [`io::ErrorKind::QuotaExceeded`] (https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.QuotaExceeded) - [`io::ErrorKind::CrossesDevices`] (https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.CrossesDevices) - [`{float}::midpoint`] (https://doc.rust-lang.org/core/primitive.f32.html#method.midpoint) - [Unsigned `{integer}::midpoint`] (https://doc.rust-lang.org/std/primitive.u64.html#method.midpoint) - [`NonZeroU*::midpoint`] (https://doc.rust-lang.org/std/num/type.NonZeroU32.html#method.midpoint) - [impl `std::iter::Extend` for tuples with arity 1 through 12] (https://doc.rust-lang.org/stable/std/iter/trait.Extend.html#impl-Extend%3C(A,)%3E-for-(EA,)) - [`FromIterator<(A, ...)>` for tuples with arity 1 through 12] (https://doc.rust-lang.org/stable/std/iter/trait.FromIterator.html#impl-FromIterator%3C(EA,)%3E-for-(A,)) - [`std::task::Waker::noop`] (https://doc.rust-lang.org/stable/std/task/struct.Waker.html#method.noop) These APIs are now stable in const contexts: - [`mem::size_of_val`] (https://doc.rust-lang.org/stable/std/mem/fn.size_of_val.html) - [`mem::align_of_val`] (https://doc.rust-lang.org/stable/std/mem/fn.align_of_val.html) - [`Layout::for_value`] (https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.for_value) - [`Layout::align_to`] (https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.align_to) - [`Layout::pad_to_align`] (https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.pad_to_align) - [`Layout::extend`] (https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.extend) - [`Layout::array`] (https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.array) - [`std::mem::swap`] (https://doc.rust-lang.org/stable/std/mem/fn.swap.html) - [`std::ptr::swap`] (https://doc.rust-lang.org/stable/std/ptr/fn.swap.html) - [`NonNull::new`] (https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.new) - [`HashMap::with_hasher`] (https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html#method.with_hasher) - [`HashSet::with_hasher`] (https://doc.rust-lang.org/stable/std/collections/struct.HashSet.html#method.with_hasher) - [`BuildHasherDefault::new`] (https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new) - [`<float>::recip`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.recip) - [`<float>::to_degrees`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_degrees) - [`<float>::to_radians`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_radians) - [`<float>::max`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.max) - [`<float>::min`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.min) - [`<float>::clamp`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.clamp) - [`<float>::abs`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.abs) - [`<float>::signum`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.signum) - [`<float>::copysign`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#method.copysign) - [`MaybeUninit::write`] (https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.write) Cargo ----- - [Add future-incompatibility warning against keywords in cfgs and add raw-idents] (rust-lang/cargo#14671) - [Stabilize higher precedence trailing flags] (rust-lang/cargo#14900) - [Pass `CARGO_CFG_FEATURE` to build scripts] (rust-lang/cargo#14902) Rustdoc ----- - [Doc comment on impl blocks shows the first line, even when the impl block is collapsed] (rust-lang/rust#132155) Compatibility Notes ------------------- - [`rustc` no longer treats the `test` cfg as a well known check-cfg] (rust-lang/rust#131729), instead it is up to the build systems and users of `--check-cfg`[^check-cfg] to set it as a well known cfg using `--check-cfg=cfg(test)`. This is done to enable build systems like Cargo to set it conditionally, as not all source files are suitable for unit tests. [Cargo (for now) unconditionally sets the `test` cfg as a well known cfg] (rust-lang/cargo#14963). [^check-cfg]: https://doc.rust-lang.org/nightly/rustc/check-cfg.html - [Disable potentially incorrect type inference if there are trivial and non-trivial where-clauses] (rust-lang/rust#132325) - `std::env::home_dir()` has been deprecated for years, because it can give surprising results in some Windows configurations if the `HOME` environment variable is set (which is not the normal configuration on Windows). We had previously avoided changing its behavior, out of concern for compatibility with code depending on this non-standard configuration. Given how long this function has been deprecated, we're now fixing its behavior as a bugfix. A subsequent release will remove the deprecation for this function. - [Make `core::ffi::c_char` signedness more closely match that of the platform-default `char`] (rust-lang/rust#132975) This changed `c_char` from an `i8` to `u8` or vice versa on many Tier 2 and 3 targets (mostly Arm and RISC-V embedded targets). The new definition may result in compilation failures but fixes compatibility issues with C. The `libc` crate matches this change as of its 0.2.169 release. - [When compiling a nested `macro_rules` macro from an external crate, the content of the inner `macro_rules` is now built with the edition of the external crate, not the local crate.] (rust-lang/rust#133274) - [Increase `sparcv9-sun-solaris` and `x86_64-pc-solaris` Solaris baseline to 11.4.] (rust-lang/rust#133293) - [Show `abi_unsupported_vector_types` lint in future breakage reports] (rust-lang/rust#133374) - [Error if multiple super-trait instantiations of `dyn Trait` need associated types to be specified but only one is provided] (rust-lang/rust#133392) - [Change `powerpc64-ibm-aix` default `codemodel` to large] (rust-lang/rust#133811) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Build `x86_64-unknown-linux-gnu` with LTO for C/C++ code (e.g., `jemalloc`)] (rust-lang/rust#134690)

This MR contains the following updates: | Package | Update | Change | |---|---|---| | [rust](https://github.com/rust-lang/rust) | minor | `1.84.1` -> `1.85.0` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>rust-lang/rust (rust)</summary> ### [`v1.85.0`](https://github.com/rust-lang/rust/blob/HEAD/RELEASES.md#Version-1850-2025-02-20) [Compare Source](rust-lang/rust@1.84.1...1.85.0) \========================== <a id="1.85.0-Language"></a> ## Language - [The 2024 Edition is now stable.](rust-lang/rust#133349) See [the edition guide](https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html) for more details. - [Stabilize async closures](rust-lang/rust#132706) See [RFC 3668](https://rust-lang.github.io/rfcs/3668-async-closures.html) for more details. - [Stabilize `#[diagnostic::do_not_recommend]`](rust-lang/rust#132056) - [Add `unpredictable_function_pointer_comparisons` lint to warn against function pointer comparisons](rust-lang/rust#118833) - [Lint on combining `#[no_mangle]` and `#[export_name]` attributes.](rust-lang/rust#131558) <a id="1.85.0-Compiler"></a> ## Compiler - [The unstable flag `-Zpolymorphize` has been removed](rust-lang/rust#133883), see rust-lang/compiler-team#810 for some background. <a id="1.85.0-Platform-Support"></a> ## Platform Support - [Promote `powerpc64le-unknown-linux-musl` to tier 2 with host tools](rust-lang/rust#133801) Refer to Rust's \[platform support page]\[platform-support-doc] for more information on Rust's tiered platform support. <a id="1.85.0-Libraries"></a> ## Libraries - [Panics in the standard library now have a leading `library/` in their path](rust-lang/rust#132390) - [`std::env::home_dir()` on Windows now ignores the non-standard `$HOME` environment variable](rust-lang/rust#132515) It will be un-deprecated in a subsequent release. - [Add `AsyncFn*` to the prelude in all editions.](rust-lang/rust#132611) <a id="1.85.0-Stabilized-APIs"></a> ## Stabilized APIs - [`BuildHasherDefault::new`](https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new) - [`ptr::fn_addr_eq`](https://doc.rust-lang.org/std/ptr/fn.fn_addr_eq.html) - [`io::ErrorKind::QuotaExceeded`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.QuotaExceeded) - [`io::ErrorKind::CrossesDevices`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.CrossesDevices) - [`{float}::midpoint`](https://doc.rust-lang.org/core/primitive.f32.html#method.midpoint) - [Unsigned `{integer}::midpoint`](https://doc.rust-lang.org/std/primitive.u64.html#method.midpoint) - [`NonZeroU*::midpoint`](https://doc.rust-lang.org/std/num/type.NonZeroU32.html#method.midpoint) - [impl `std::iter::Extend` for tuples with arity 1 through 12](https://doc.rust-lang.org/stable/std/iter/trait.Extend.html#impl-Extend%3C$A,$%3E-for-$EA,$) - [`FromIterator<(A, ...)>` for tuples with arity 1 through 12](https://doc.rust-lang.org/stable/std/iter/trait.FromIterator.html#impl-FromIterator%3C$EA,$%3E-for-$A,$) - [`std::task::Waker::noop`](https://doc.rust-lang.org/stable/std/task/struct.Waker.html#method.noop) These APIs are now stable in const contexts: - [`mem::size_of_val`](https://doc.rust-lang.org/stable/std/mem/fn.size_of_val.html) - [`mem::align_of_val`](https://doc.rust-lang.org/stable/std/mem/fn.align_of_val.html) - [`Layout::for_value`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.for_value) - [`Layout::align_to`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.align_to) - [`Layout::pad_to_align`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.pad_to_align) - [`Layout::extend`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.extend) - [`Layout::array`](https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.array) - [`std::mem::swap`](https://doc.rust-lang.org/stable/std/mem/fn.swap.html) - [`std::ptr::swap`](https://doc.rust-lang.org/stable/std/ptr/fn.swap.html) - [`NonNull::new`](https://doc.rust-lang.org/stable/std/ptr/struct.NonNull.html#method.new) - [`HashMap::with_hasher`](https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html#method.with_hasher) - [`HashSet::with_hasher`](https://doc.rust-lang.org/stable/std/collections/struct.HashSet.html#method.with_hasher) - [`BuildHasherDefault::new`](https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new) - [`<float>::recip`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.recip) - [`<float>::to_degrees`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_degrees) - [`<float>::to_radians`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.to_radians) - [`<float>::max`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.max) - [`<float>::min`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.min) - [`<float>::clamp`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.clamp) - [`<float>::abs`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.abs) - [`<float>::signum`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.signum) - [`<float>::copysign`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.copysign) - [`MaybeUninit::write`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#method.write) <a id="1.85.0-Cargo"></a> ## Cargo - [Add future-incompatibility warning against keywords in cfgs and add raw-idents](rust-lang/cargo#14671) - [Stabilize higher precedence trailing flags](rust-lang/cargo#14900) - [Pass `CARGO_CFG_FEATURE` to build scripts](rust-lang/cargo#14902) <a id="1.85.0-Rustdoc"></a> ## Rustdoc - [Doc comment on impl blocks shows the first line, even when the impl block is collapsed](rust-lang/rust#132155) <a id="1.85.0-Compatibility-Notes"></a> ## Compatibility Notes - [`rustc` no longer treats the `test` cfg as a well known check-cfg](rust-lang/rust#131729), instead it is up to the build systems and users of `--check-cfg`\[^check-cfg] to set it as a well known cfg using `--check-cfg=cfg(test)`. This is done to enable build systems like Cargo to set it conditionally, as not all source files are suitable for unit tests. [Cargo (for now) unconditionally sets the `test` cfg as a well known cfg](rust-lang/cargo#14963). \[^check-cfg]: https://doc.rust-lang.org/nightly/rustc/check-cfg.html - [Disable potentially incorrect type inference if there are trivial and non-trivial where-clauses](rust-lang/rust#132325) - `std::env::home_dir()` has been deprecated for years, because it can give surprising results in some Windows configurations if the `HOME` environment variable is set (which is not the normal configuration on Windows). We had previously avoided changing its behavior, out of concern for compatibility with code depending on this non-standard configuration. Given how long this function has been deprecated, we're now fixing its behavior as a bugfix. A subsequent release will remove the deprecation for this function. - [Make `core::ffi::c_char` signedness more closely match that of the platform-default `char`](rust-lang/rust#132975) This changed `c_char` from an `i8` to `u8` or vice versa on many Tier 2 and 3 targets (mostly Arm and RISC-V embedded targets). The new definition may result in compilation failures but fixes compatibility issues with C. The `libc` crate matches this change as of its 0.2.169 release. - [When compiling a nested `macro_rules` macro from an external crate, the content of the inner `macro_rules` is now built with the edition of the external crate, not the local crate.](rust-lang/rust#133274) - [Increase `sparcv9-sun-solaris` and `x86_64-pc-solaris` Solaris baseline to 11.4.](rust-lang/rust#133293) - [Show `abi_unsupported_vector_types` lint in future breakage reports](rust-lang/rust#133374) - [Error if multiple super-trait instantiations of `dyn Trait` need associated types to be specified but only one is provided](rust-lang/rust#133392) - [Change `powerpc64-ibm-aix` default `codemodel` to large](rust-lang/rust#133811) <a id="1.85.0-Internal-Changes"></a> ## Internal Changes These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Build `x86_64-unknown-linux-gnu` with LTO for C/C++ code (e.g., `jemalloc`)](rust-lang/rust#134690) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this MR, check this box --- This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).

As noted in rust-lang#132975 (comment), the default for userland apps is to follow the architecture defaults, the -funsigned-char flag only applies to kernel builds.

…viper Revert vita's c_char back to i8 # Description Hi! rust-lang#132975 changed the definition of `c_char` from i8 to u8 for most ARM targets. While that would usually be correct, [VITASDK uses signed chars by default](https://github.com/vitasdk/buildscripts/blob/master/patches/gcc/0001-gcc-10.patch#L33-L34). The Clang definitions are incorrect because Clang is not (yet?) supported by the vita commmunity / `VITADSK`, On the Rust side, the pre-compiled libraries the user can link to are all compiled using vita's `gcc` and [we set `TARGET_CC` and `TARGET_CXX`](https://github.com/vita-rust/cargo-vita/blob/d564a132cbd43947118c0d6d0ebfbea7d1dd7fa7/src/commands/build.rs#L230) in `cargo vita` for build scripts using `cc`. I'm creating it as a draft PR so that we can discuss it and possibly get it approved here, but wait to merge the [libc side](rust-lang/libc#4258) and get a libc version first, as having the definitions out of sync breaks std. As a nightly-only target it can be confusing/frustrating for new users when the latest nightly, which is the default, is broken.

rustbot assigned cuviper Nov 13, 2024

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Nov 13, 2024

rustbot assigned joshtriplett and unassigned cuviper Nov 13, 2024

maurer suggested changes Nov 13, 2024

View reviewed changes

library/core/src/ffi/mod.rs Outdated Show resolved Hide resolved

library/core/src/ffi/mod.rs Outdated Show resolved Hide resolved

arichardson force-pushed the ffi-c-char branch from 05aff14 to 05f561b Compare November 13, 2024 19:09

arichardson force-pushed the ffi-c-char branch 2 times, most recently from c19462d to 4d8abde Compare November 13, 2024 19:39

rustbot added the T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. label Nov 14, 2024

rustbot assigned BurntSushi and unassigned joshtriplett Nov 14, 2024

arichardson requested a review from maurer November 14, 2024 00:44

arichardson mentioned this pull request Nov 15, 2024

c_char signedness doesn't match with Clang's default on various no-std and tier 3 targets #129945

Closed

arichardson force-pushed the ffi-c-char branch from 4d8abde to 5e82b5e Compare November 15, 2024 23:40

arichardson force-pushed the ffi-c-char branch from 5e82b5e to 4e3c262 Compare December 4, 2024 17:43

taiki-e mentioned this pull request Jan 28, 2025

Update comments and sort target_arch in c_char_definition #136173

Merged

pheki mentioned this pull request Feb 7, 2025

Revert vita's c_char back to i8 #136667

Merged

arichardson mentioned this pull request Feb 9, 2025

release/20.x: [CSKY] Default to unsigned char llvm/llvm-project#126436

Merged

pdgendt mentioned this pull request Feb 25, 2025

qemu_riscv32/qemu_virt_riscv32/smp sample.rust/bench.plain fail zephyrproject-rtos/zephyr#86310

Closed

rusty-snake mentioned this pull request Mar 6, 2025

Fix typo in buffer.rs bytecodealliance/rustix#1386

Merged

tgross35 mentioned this pull request Mar 17, 2025

Remove the libc version of core::ffi primitives rust-lang/libc#4257

Open

bugadani mentioned this pull request Nov 24, 2025

Build failure of esp-rom-sys for esp32 esp-rs/esp-hal#4545

Open

Uh oh!

Conversation

arichardson commented Nov 13, 2024 • edited by tgross35 Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

rustbot commented Nov 13, 2024

Uh oh!

arichardson commented Nov 13, 2024

Uh oh!

rustbot commented Nov 13, 2024

Uh oh!

beetrees commented Nov 13, 2024

Uh oh!

maurer left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

maurer commented Nov 13, 2024

Uh oh!

beetrees commented Nov 13, 2024

Uh oh!

arichardson commented Nov 13, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

arichardson commented Nov 13, 2024

Uh oh!

joshtriplett commented Nov 14, 2024

Uh oh!

tgross35 commented Nov 15, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

arichardson commented Nov 16, 2024

Uh oh!

taiki-e commented Nov 19, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

arichardson commented Dec 4, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

20 participants

arichardson commented Nov 13, 2024 •

edited by tgross35

Loading

arichardson commented Nov 13, 2024 •

edited

Loading

tgross35 commented Nov 15, 2024 •

edited

Loading

taiki-e commented Nov 19, 2024 •

edited

Loading