Add NuttX based targets for RISC-V and ARM
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. It is scalable from 8-bit to 64-bit microcontroller environments. The primary governing standards in NuttX are POSIX and ANSI standards.
NuttX adopts additional standard APIs from Unix and other common RTOSs, such as VxWorks. These APIs are used for functionality not available under the POSIX and ANSI standards. However, some APIs, like fork(), are not appropriate for deeply-embedded environments and are not implemented in NuttX.
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
I'll be adding libstd support for NuttX in the future, but for now I'll just add the targets.
Tier 3 policy:
> A tier 3 target must have a designated developer or developers (the "target
> maintainers") on record to be CCed when issues arise regarding the target.
> (The mechanism to track and CC such developers may evolve over time.)
I will be the target maintainer for this target on matters that pertain to the NuttX part of the triple. For matters pertaining to the riscv or arm part of the triple, there should be no difference from all other targets. If there are issues, I will address issues regarding the target.
> Targets must use naming consistent with any existing targets; for instance, a
> target for the same CPU or OS as an existing Rust target should use the same
> name for that CPU or OS. Targets should normally use the same names and
> naming conventions as used elsewhere in the broader ecosystem beyond Rust
> (such as in other toolchains), unless they have a very good reason to
> diverge. Changing the name of a target can be highly disruptive, especially
> once the target reaches a higher tier, so getting the name right is important
> even for a tier 3 target.
This is a new supported OS, so I have taken the origin target like `riscv32imac-unknown-none-elf` or `thumbv7m-none-eabi` and changed the `os` section to `nuttx`.
> Target names should not introduce undue confusion or ambiguity unless
> absolutely necessary to maintain ecosystem compatibility. For example, if
> the name of the target makes people extremely likely to form incorrect
> beliefs about what it targets, the name should be changed or augmented to
> disambiguate it.
I feel that the target name does not introduce any ambiguity.
> Tier 3 targets may have unusual requirements to build or use, but must not
> create legal issues or impose onerous legal terms for the Rust project or for
> Rust developers or users.
The only unusual requirement for building the compiler-builtins crate is a standard RISC-V or ARM C compiler supported by cc-rs, and using this target does not require any additional software beyond what is shipped by rustup.
> The target must not introduce license incompatibilities.
All of the additional code will use Apache-2.0.
> Anything added to the Rust repository must be under the standard Rust
> license (`MIT OR Apache-2.0`).
Agreed, and there is no problem here.
> The target must not cause the Rust tools or libraries built for any other
> host (even when supporting cross-compilation to the target) to depend
> on any new dependency less permissive than the Rust licensing policy. This
> applies whether the dependency is a Rust crate that would require adding
> new license exceptions (as specified by the `tidy` tool in the
> rust-lang/rust repository), or whether the dependency is a native library
> or binary. In other words, the introduction of the target must not cause a
> user installing or running a version of Rust or the Rust tools to be
> subject to any new license requirements.
No new dependencies are added.
> Compiling, linking, and emitting functional binaries, libraries, or other
> code for the target (whether hosted on the target itself or cross-compiling
> from another target) must not depend on proprietary (non-FOSS) libraries.
> Host tools built for the target itself may depend on the ordinary runtime
> libraries supplied by the platform and commonly used by other applications
> built for the target, but those libraries must not be required for code
> generation for the target; cross-compilation to the target must not require
> such libraries at all. For instance, `rustc` built for the target may
> depend on a common proprietary C runtime library or console output library,
> but must not depend on a proprietary code generation library or code
> optimization library. Rust's license permits such combinations, but the
> Rust project has no interest in maintaining such combinations within the
> scope of Rust itself, even at tier 3.
Linking is performed by rust-lld
> "onerous" here is an intentionally subjective term. At a minimum, "onerous"
> legal/licensing terms include but are *not* limited to: non-disclosure
> requirements, non-compete requirements, contributor license agreements
> (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms,
> requirements conditional on the employer or employment of any particular
> Rust developers, revocable terms, any requirements that create liability
> for the Rust project or its developers or users, or any requirements that
> adversely affect the livelihood or prospects of the Rust project or its
> developers or users.
There are no terms. NuttX is distributed under the Apache 2.0 license.
> Neither this policy nor any decisions made regarding targets shall create any
> binding agreement or estoppel by any party. If any member of an approving
> Rust team serves as one of the maintainers of a target, or has any legal or
> employment requirement (explicit or implicit) that might affect their
> decisions regarding a target, they must recuse themselves from any approval
> decisions regarding the target's tier status, though they may otherwise
> participate in discussions.
I'm not the reviewer here.
> This requirement does not prevent part or all of this policy from being
> cited in an explicit contract or work agreement (e.g. to implement or
> maintain support for a target). This requirement exists to ensure that a
> developer or team responsible for reviewing and approving a target does not
> face any legal threats or obligations that would prevent them from freely
> exercising their judgment in such approval, even if such judgment involves
> subjective matters or goes beyond the letter of these requirements.
Again I'm not the reviewer here.
> Tier 3 targets should attempt to implement as much of the standard libraries
> as possible and appropriate (`core` for most targets, `alloc` for targets
> that can support dynamic memory allocation, `std` for targets with an
> operating system or equivalent layer of system-provided functionality), but
> may leave some code unimplemented (either unavailable or stubbed out as
> appropriate), whether because the target makes it impossible to implement or
> challenging to implement. The authors of pull requests are not obligated to
> avoid calling any portions of the standard library on the basis of a tier 3
> target not implementing those portions.
> The target must provide documentation for the Rust community explaining how
> to build for the target, using cross-compilation if possible. If the target
> supports running binaries, or running tests (even if they do not pass), the
> documentation must explain how to run such binaries or tests for the target,
> using emulation if possible or dedicated hardware if necessary.
Building is described in platform support doc, but libstd is not supported now, I'll implement it later.
> Tier 3 targets must not impose burden on the authors of pull requests, or
> other developers in the community, to maintain the target. In particular,
> do not post comments (automated or manual) on a PR that derail or suggest a
> block on the PR based on a tier 3 target. Do not send automated messages or
> notifications (via any medium, including via ``@`)` to a PR author or others
> involved with a PR regarding a tier 3 target, unless they have opted into
> such messages.
Understood.
> Backlinks such as those generated by the issue/PR tracker when linking to
> an issue or PR are not considered a violation of this policy, within
> reason. However, such messages (even on a separate repository) must not
> generate notifications to anyone involved with a PR who has not requested
> such notifications.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2
> or tier 1 target, and must not knowingly break another tier 3 target without
> approval of either the compiler team or the maintainers of the other tier 3
> target.
I believe I didn't break any other target.
> In particular, this may come up when working on closely related targets,
> such as variations of the same architecture with different features. Avoid
> introducing unconditional uses of features that another variation of the
> target may not have; use conditional compilation or runtime detection, as
> appropriate, to let each target run code supported by that target.
I think there are no such problems in this PR.
> Tier 3 targets must be able to produce assembly using at least one of
> rustc's supported backends from any host target. (Having support in a fork
> of the backend is not sufficient, it must be upstream.)
Yes, it use standard RISCV or ARM backend to generate assembly.
match exhaustiveness: Expand or-patterns as a separate step
To compute exhaustiveness, we must expand or-patterns. Previously, we expanded them at the same time that we pushed patterns into the matrix. This made it harder to track pattern reachability, because the or-pattern itself would never show up in the matrix so we had to recover missing information.
This PR changes that: we no longer expand or-patterns as we push them into the matrix. Instead, if we find an or-pattern in the matrix we expand them in a step very much like the specialization we already do. This simplifies a bunch of things, and should greatly simplify the implementation of https://github.com/rust-lang/rust/issues/127870.
r? `@compiler-errors`
Migrate `staticlib-blank-lib`, `rlib-format-packed-bundled-libs-3` and `issue-97463-abi-param-passing` `run-make` tests to rmake
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
Please try:
try-job: aarch64-gnu
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-mingw
try-job: x86_64-msvc
try-job: x86_64-gnu-llvm-18
Move rustbook to its own workspace.
This moves rustbook (the wrapper around mdbook) to its own Cargo workspace. This is done for two reasons:
- Some users want to avoid having to check out documentation submodules if they are not working on documentation. These submodules are required for submodules that have Cargo dependencies in the tree (such as mdbook preprocessors).
- The [pinned `memchr`](eb72697e41/compiler/rustc_ast/Cargo.toml (L10)) is causing problems with updating. That pin is only necessary for the standard library, but unfortunately it is affecting all other crates.
This will have some drawbacks:
- A slight increase in the vendor directory size. My measurement shows about a 14M increase (0.7%), but somehow the compressed filesize is smaller.
- The dependencies for rustbook now need to be managed separately. I have updated the cron job to try to mitigate this.
- There will be a slight dist build time penalty. I'm not sure what it will be, since it heavily depends on the machine, but I suspect in the 30-45s range.
- Adds more complexity to things like bootstrap and tidy.
There are a few other alternatives considered:
- Publish preprocessors on crates.io. This adds the burden of publishing every change, and ensuring those publishes happen and the sources don't get out of sync, and somehow syncing those updates back to rust-lang/rust during the automatic updates. This is also more work.
- Move the submodules to subtrees. These have the added burden of doing updates in a way that is more difficult than submodules. I believe it also causes problems with GitHub's `#NNNN` tagging and closing issues. This is also more work.
The only thing I haven't tested here is the cron job. However, there's a pretty decent chance this won't pass CI, or that I missed something.
Rollup of 9 pull requests
Successful merges:
- #117932 (Correct rustdoc section where we talk about rustdoc emitting errors on invalid code)
- #125990 (Rename `deprecated_safe` lint to `deprecated_safe_2024`)
- #127506 (rustc_target: add known safe s390x target features)
- #127820 (Rewrite and rename `issue-14698`. `issue-33329` and `issue-107094` `run-make` tests to rmake or ui)
- #127923 (Use reuse tool 4.0)
- #128008 (Start using `#[diagnostic::do_not_recommend]` in the standard library)
- #128036 (add more tests)
- #128051 (rustdoc: revert spacing change in item-table)
- #128059 (Add regression test for items list size (#128023))
r? `@ghost`
`@rustbot` modify labels: rollup
Start using `#[diagnostic::do_not_recommend]` in the standard library
This commit starts using `#[diagnostic::do_not_recommend]` in the standard library to improve some error messages. In this case we just hide a certain nightly only impl as suggested in #121521
The result in not perfect yet, but at least the `Yeet` suggestion is not shown anymore. I would consider that as a minor improvement.
Use reuse tool 4.0
This change upgrades us to reuse-tool 4.0.3, which has a new TOML format configuration instead of the old `.reuse/dep5` Debian-style file.
* Updated requirements file to install reuse-4.0.3
* Ran `reuse convert-dep5` to switch to new file format
* Switched over to `override` so the `REUSE.toml` file takes precedence over whatever random Copyright strings `reuse` finds in the source tree.
Should fix https://github.com/rust-lang/rust/issues/127361
Rewrite and rename `issue-14698`. `issue-33329` and `issue-107094` `run-make` tests to rmake or ui
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
try-job: armhf-gnu
try-job: test-various
try-job: aarch64-apple
try-job: x86_64-msvc
rustc_target: add known safe s390x target features
This pull request adds known safe target features for s390x (aka IBM Z systems).
Currently, these features are unstable since stabilizing the target features requires submitting proposals.
The `vector` feature was added in IBM Z13 (`arch11`), and this is a SIMD feature for the newer IBM Z systems.
The `backchain` attribute is the IBM Z way of adding frame pointers like unwinding capabilities (the "frame-pointer" switch on IBM Z and IBM POWER platforms will add _emulated_ frame pointers to the binary, which profilers can't use for unwinding the stack).
Both attributes can be applied at the LLVM module or function levels. However, the `backchain` attribute has to be enabled for all the functions in the call stack to get a successful unwind process.
Uplift most type-system related error reporting from `rustc_infer` to `rustc_trait_selection`
Completes the major part of #127492. The only cleanup that's needed afterwards is to actually use normalization in favor of the callback where needed, and deleting `can_eq_shallow`.
r? lcnr
Sorry for the large diff! Would prefer if comments can be handled in a follow-up (unless they're absolutely dealbreakers) because it seems bitrotty to let this sit.
Now that we have reuse-tool 4.0, we no longer need to massage the JSON license data to collapse LLVM into a single copyright notice and license - reuse-tool can do it for us using an annotation in REUSE.toml.
This effectively reverts c6eb03b.
Clean up warnings + `unsafe_op_in_unsafe_fn` when building std for armv6k-nintendo-3ds
See #127747
ping `@AzureMarker` `@Meziu`
I could only find one instance needing an extra `unsafe` that was not also shared with many other `unix` targets (presumably these will get covered in larger sweeping changes, I didn't want to introduce churn that would potentially conflict with those). The one codepath I found is shared with `vita` however, so also pinging `@nikarh` `@pheki` `@zetanumbers` just to make sure they're aware of this change.
Also removed one unused import from `process_unsupported` which should simply fix the warning for any target that uses it.
Update wasi-sdk in CI to latest release
This commit updates the `wasi-sdk` download used by the `wasm32-wasi*` targets. The motivation for this commit is generally just "keep things up to date" and is not intended to cause any issues or differences from before, just a routine update.
Rewrite `test-float-parse` in Rust
Migrate from the currently broken Rust + Python `test-float-parse` to a Rust implementation. This newer version should be significantly faster (tests execute in parallel with threads, rather than series across multiple processes, which also eliminates the "...the worker processes are leaked and stick around forever" message), and should be significantly easier to extend to the new float types.
Since this is faster and hopefully more stable, we should be able to launch it with `x` and run the faster tests in CI.
Add missing try_new_uninit_slice_in and try_new_zeroed_slice_in
The methods for fallible slice allocation in a given allocator were missing from `Box`, which was an oversight according to https://github.com/rust-lang/wg-allocators/issues/130
This PR adds them as `try_new_uninit_slice_in` and `try_new_zeroed_slice_in`. I simply copy-pasted the implementations of `try_new_uninit_slice` and `try_new_zeroed_slice` and adusted doc comment, typings, and the allocator it uses internally.
Also adds missing punctuation to the doc comments of `try_new_uninit_slice` and `try_new_zeroed_slice`.
Related issue is https://github.com/rust-lang/rust/issues/32838 (Allocator traits and std::heap) *I think*. Also relevant is https://github.com/rust-lang/rust/issues/63291, but I did not add the corresponding `#[unstable]` proc macro, since `try_new_uninit_slice` and `try_new_zeroed_slice` are also not annotated with it.
Try to fix ICE from re-interning an AllocId with different allocation contents
As far as I can tell, based on my investigation in https://github.com/rust-lang/rust/issues/126741, the racy decoding scheme implemented here was never fully correct, but the arrangement of Allocations that's required to ICE the compiler requires some very specific MIR optimizations to create. As far as I can tell, GVN likes to create the problematic pattern, which is why we're noticing this problem now.
So the solution here is to not do racy decoding. If two threads race to decoding an AllocId, one of them is going to sit on a lock until the other is done.
This commit starts using `#[diagnostic::do_not_recommend]` in the
standard library to improve some error messages. In this case we just
hide a certain nightly only impl as suggested in #121521
Don't output incremental test artifacts into working directory
Currently tests can ICE when the test spits out `inc-fat` incremental artifacts directly into the top of the git checkout, and then the compiler version changes, and it reads nonsense incremental artifacts on a subsequent test run.
r? `@oli-obk`
cc `@Oneirical,` I think you added this -- I think the right flag to add when porting `-Cincremental` run-make tests is to use `//@ incremental` rather than manually specifying the `-Cincremental` rustflag.
Explain why we require `_` for empty patterns
This adds a note to the "non-exhaustive patterns" diagnostic to explain why we sometimes require extra `_` patterns on empty types. This is one of the two diagnostic improvements I wanted to do before [stabilizing `min_exhaustive_patterns`](https://github.com/rust-lang/rust/pull/122792).
r? ``@compiler-errors``
