Add spawn APIs for BootstrapCommand to support deferred command execution
This PR adds new deferred command support in the ExecutionContext and provides APIs to spawn commands and wait for their completion. This structure enables moving away from the start_process helper functions towards a more unified and reusable command execution flow.
r? ````@Kobzol````
CodeGen: rework Aggregate implemention for rvalue_creates_operand cases
A non-trivial refactor pulled out from rust-lang/rust#138759
r? workingjubilee
The previous implementation I'd written here based on `index_by_increasing_offset` is complicated to follow and difficult to extend to non-structs.
This changes the implementation, without actually changing any codegen (thus no test changes either), to be more like the existing `extract_field` (<2b0274c71d/compiler/rustc_codegen_ssa/src/mir/operand.rs (L345-L425)>) in that it allows setting a particular field directly.
Notably I've found this one much easier to get right, in particular because having the `OperandRef<Result<V, Scalar>>` gives a really useful thing to include in ICE messages if something did happen to go wrong.
Affirm `-Cforce-frame-pointers=off` does not override
This PR exists to document that we (that is, the compiler reviewer) implicitly made a decision in rust-lang/rust#86652 that defies the expectations of some programmers. Some programmers believe `-Cforce-frame-pointers=false` should obey the programmer in all cases, forcing the compiler to avoid generating frame pointers, even if the target specification would indicate they must be generated. However, many targets rely on frame pointers for fast or sound unwinding.
T-compiler had a weekly triage meeting on 2025-05-22. This topic was put to discussion because some programmers may expect the target-overriding behavior. In that meeting we decided removing frame pointers, at least with regards to the contract of the `-Cforce-frame-pointers` option, is not required, even if `=off` is passed, and that we will not do so if the target would expect them. This follows from the documentation here: https://doc.rust-lang.org/rustc/codegen-options/index.html#force-frame-pointers
We may separately pursue trying to clarify the situation more emphatically in our documentation, or warn when people pass the option when it doesn't do anything.
Change __rust_no_alloc_shim_is_unstable to be a function
This fixes a long sequence of issues:
1. A customer reported that building for Arm64EC was broken: #138541
2. This was caused by a bug in my original implementation of Arm64EC support, namely that only functions on Arm64EC need to be decorated with `#` but Rust was decorating statics as well.
3. Once I corrected Rust to only decorate functions, I started linking failures where the linker couldn't find statics exported by dylib dependencies. This was caused by the compiler not marking exported statics in the generated DEF file with `DATA`, thus they were being exported as functions not data.
4. Once I corrected the way that the DEF files were being emitted, the linker started failing saying that it couldn't find `__rust_no_alloc_shim_is_unstable`. This is because the MSVC linker requires the declarations of statics imported from other dylibs to be marked with `dllimport` (whereas it will happily link to functions imported from other dylibs whether they are marked `dllimport` or not).
5. I then made a change to ensure that `__rust_no_alloc_shim_is_unstable` was marked as `dllimport`, but the MSVC linker started emitting warnings that `__rust_no_alloc_shim_is_unstable` was marked as `dllimport` but was declared in an obj file. This is a harmless warning which is a performance hint: anything that's marked `dllimport` must be indirected via an `__imp` symbol so I added a linker arg in the target to suppress the warning.
6. A customer then reported a similar warning when using `lld-link` (<https://github.com/rust-lang/rust/pull/140176#issuecomment-2872448443>). I don't think it was an implementation difference between the two linkers but rather that, depending on the obj that the declaration versus uses of `__rust_no_alloc_shim_is_unstable` landed in we would get different warnings, so I suppressed that warning as well: #140954.
7. Another customer reported that they weren't using the Rust compiler to invoke the linker, thus these warnings were breaking their build: <https://github.com/rust-lang/rust/pull/140176#issuecomment-2881867433>. At that point, my original change was reverted (#141024) leaving Arm64EC broken yet again.
Taking a step back, a lot of these linker issues arise from the fact that `__rust_no_alloc_shim_is_unstable` is marked as `extern "Rust"` in the standard library and, therefore, assumed to be a foreign item from a different crate BUT the Rust compiler may choose to generate it either in the current crate, some other crate that will be statically linked in OR some other crate that will by dynamically imported.
Worse yet, it is impossible while building a given crate to know if `__rust_no_alloc_shim_is_unstable` will statically linked or dynamically imported: it might be that one of its dependent crates is the one with an allocator kind set and thus that crate (which is compiled later) will decide depending if it has any dylib dependencies or not to import `__rust_no_alloc_shim_is_unstable` or generate it. Thus, there is no way to know if the declaration of `__rust_no_alloc_shim_is_unstable` should be marked with `dllimport` or not.
There is a simple fix for all this: there is no reason `__rust_no_alloc_shim_is_unstable` must be a static. It needs to be some symbol that must be linked in; thus, it could easily be a function instead. As a function, there is no need to mark it as `dllimport` when dynamically imported which avoids the entire mess above.
There may be a perf hit for changing the `volatile load` to be a `tail call`, so I'm happy to change that part back (although I question what the codegen of a `volatile load` would look like, and if the backend is going to try to use load-acquire semantics).
Build with this change applied BEFORE #140176 was reverted to demonstrate that there are no linking issues with either MSVC or MinGW: <https://github.com/rust-lang/rust/actions/runs/15078657205>
Incidentally, I fixed `tests/run-make/no-alloc-shim` to work with MSVC as I needed it to be able to test locally (FYI for #128602)
r? `@bjorn3`
cc `@jieyouxu`
Rewrite `inline` attribute parser to use new infrastructure and improve diagnostics for all parsed attributes
r? `@oli-obk`
This PR:
- creates a new parser for inline attributes
- creates consistent error messages and error codes between attribute parsers; inline and others
- as such changes a few error messages for other attributes to be (in my eyes) much more consistent
- tests ast-lowering lints introduced by rust-lang/rust#138164 since this is now useful for the first time
- Coalesce some useless error codes
Builds on top of rust-lang/rust#138164Closesrust-lang/rust#137950
Safer implementation of RepeatN
I've seen the "Use MaybeUninit for RepeatN" commit while reading This Week In Rust and immediately thought about something I've written some time ago - https://github.com/Soveu/repeat_finite/blob/master/src/lib.rs.
Using the fact, that `Option` will find niche in `(T, NonZeroUsize)`, we can construct something that has the same size as `(T, usize)` while completely getting rid of `MaybeUninit`.
This leaves only `unsafe` on `TrustedLen`, which is pretty neat.
Another refactor pulled out from 138759
The previous implementation I'd written here based on `index_by_increasing_offset` is complicated to follow and difficult to extend to non-structs.
This changes the implementation, without actually changing any codegen (thus no test changes either), to be more like the existing `extract_field` (<2b0274c71d/compiler/rustc_codegen_ssa/src/mir/operand.rs (L345-L425)>) in that it allows setting a particular field directly.
Notably I've found this one much easier to get right, in particular because having the `OperandRef<Result<V, Scalar>>` gives a really useful thing to include in ICE messages if something did happen to go wrong.
Temporarily add back -Zwasm-c-abi=spec
This allows a more gradual transition path for projects that need to use use the spec-complaint C ABI both with older and newer rustc versions.
Update cargo
6 commits in fc1518ef02b77327d70d4026b95ea719dd9b8c51..2251525ae503fa196f6d7f9ce6d32eccb2d5f044
2025-06-06 04:49:44 +0000 to 2025-06-16 22:01:27 +0000
- feat: Add custom completer for `cargo remove <TAB>` (rust-lang/cargo#15662)
- chore(deps): update msrv (3 versions) to v1.85 (rust-lang/cargo#15668)
- refactor: replace InternedString with Cow in IndexPackage (rust-lang/cargo#15559)
- highlight the correct words (rust-lang/cargo#15659)
- CHANGELOG.md: typo (rust-lang/cargo#15660)
- Use `Not::not` rather than a custom `is_false` function (rust-lang/cargo#15645)
Refresh module-level docs for `rustc_target::spec`
We have long since gone on a curveball from the flexible-target-specification RFC by introducing stability and soundness promises to the language and compiler which we often struggle with extending to target-specific implementation details. Indeed, we often *literally cannot*. We also have modified the search algorithm details. Update the comments for `rustc_target::spec` considerably.
Don't unwrap in enzyme builds in case of missing llvm-config
r? `@onur-ozkan`
For some reason x.py was now panicking in this location, so I also removed the unwrap here.
part 2 of https://github.com/rust-lang/rust/pull/140000, there shouldn't be other locations where we check for llvm-config.
Windows: Use anonymous pipes in Command
When setting `Stdio::pipe` on `Command` we want to create an anonymous pipe that can be used asynchronously (at least on our end). Usually we'd use [`CreatePipe`](https://learn.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-createpipe) to open anonymous pipes but unfortunately it opens pipes for synchronous access. The alternative is to use [`CreateNamedPipeW`](https://learn.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-createnamedpipew) which does allow asynchronous access but that requires giving a file name to the pipe. So we currently have this awful hack where we attempt to emulate anonymous pipes using `CreateNamedPipeW` by attempting to create a unique name and looping until we find one that doesn't already exist.
The better option is to use the lower level [`NtCreateNamedPipeFile`](https://learn.microsoft.com/en-us/windows/win32/devnotes/nt-create-named-pipe-file) (which is used internally by both `CreatePipe` and `CreateNamedPipeW`). This function wasn't documented until a few years ago but now that it is it's ok for us to use it.
try-job: *msvc*
try-job: *mingw*
rustdoc: make srcIndex no longer a global variable
this is one-time initialization data, it can just
be a function parameter.
while we're doing that, we can more the json parsing into the function and save a few extra bytes of storage for free, at least in the case of multiple crates in a doc bundle.
fixes https://github.com/rust-lang/rust/issues/138467
Sized Hierarchy: Part I
This patch implements the non-const parts of rust-lang/rfcs#3729. It introduces two new traits to the standard library, `MetaSized` and `PointeeSized`. See the RFC for the rationale behind these traits and to discuss whether this change makes sense in the abstract.
These traits are unstable (as is their constness), so users cannot refer to them without opting-in to `feature(sized_hierarchy)`. These traits are not behind `cfg`s as this would make implementation unfeasible, there would simply be too many `cfg`s required to add the necessary bounds everywhere. So, like `Sized`, these traits are automatically implemented by the compiler.
RFC 3729 describes changes which are necessary to preserve backwards compatibility given the introduction of these traits, which are implemented and as follows:
- `?Sized` is rewritten as `MetaSized`
- `MetaSized` is added as a default supertrait for all traits w/out an explicit sizedness supertrait already.
There are no edition migrations implemented in this, as these are primarily required for the constness parts of the RFC and prior to stabilisation of this (and so will come in follow-up PRs alongside the const parts). All diagnostic output should remain the same (showing `?Sized` even if the compiler sees `MetaSized`) unless the `sized_hierarchy` feature is enabled.
Due to the use of unstable extern types in the standard library and rustc, some bounds in both projects have had to be relaxed already - this is unfortunate but unavoidable so that these extern types can continue to be used where they were before. Performing these relaxations in the standard library and rustc are desirable longer-term anyway, but some bounds are not as relaxed as they ideally would be due to the inability to relax `Deref::Target` (this will be investigated separately).
It is hoped that this is implemented such that it could be merged and these traits could exist "under the hood" without that being observable to the user (other than in any performance impact this has on the compiler, etc). Some details might leak through due to the standard library relaxations, but this has not been observed in test output.
**Notes:**
- Any commits starting with "upstream:" can be ignored, as these correspond to other upstream PRs that this is based on which have yet to be merged.
- This best reviewed commit-by-commit. I've attempted to make the implementation easy to follow and keep similar changes and test output updates together.
- Each commit has a short description describing its purpose.
- This patch is large but it's primarily in the test suite.
- I've worked on the performance of this patch and a few optimisations are implemented so that the performance impact is neutral-to-minor.
- `PointeeSized` is a different name from the RFC just to make it more obvious that it is different from `std::ptr::Pointee` but all the names are yet to be bikeshed anyway.
- `@nikomatsakis` has confirmed [that this can proceed as an experiment from the t-lang side](https://rust-lang.zulipchat.com/#narrow/channel/435869-project-goals/topic/SVE.20and.20SME.20on.20AArch64.20.28goals.23270.29/near/506196491)
- FCP in https://github.com/rust-lang/rust/pull/137944#issuecomment-2912207485Fixesrust-lang/rust#79409.
r? `@ghost` (I'll discuss this with relevant teams to find a reviewer)
