Fix `ByMove` coroutine-closure shim (for 2021 precise closure capturing behavior)
This PR reworks the way that we perform the `ByMove` coroutine-closure shim to account for the fact that the upvars of the outer coroutine-closure and the inner coroutine might not line up due to edition-2021 closure capture rules changes.
Specifically, the number of upvars may differ *and/or* the inner coroutine may have additional projections applied to an upvar. This PR reworks the information we pass into the `ByMoveBody` MIR visitor to account for both of these facts.
I tried to leave comments explaining exactly what everything is doing, but let me know if you have questions.
r? oli-obk
Safe Transmute: Compute transmutability from `rustc_target::abi::Layout`
In its first step of computing transmutability, `rustc_transmutability` constructs a byte-level representation of type layout (`Tree`). Previously, this representation was computed for ADTs by inspecting the ADT definition and performing our own layout computations. This process was error-prone, verbose, and limited our ability to analyze many types (particularly default-repr types).
In this PR, we instead construct `Tree`s from `rustc_target::abi::Layout`s. This helps ensure that layout optimizations are reflected our analyses, and increases the kinds of types we can now analyze, including:
- default repr ADTs
- transparent unions
- `UnsafeCell`-containing types
Overall, this PR expands the expressvity of `rustc_transmutability` to be much closer to the transmutability analysis performed by miri. Future PRs will work to close the remaining gaps (e.g., support for `Box`, raw pointers, `NonZero*`, coroutines, etc.).
r? `@compiler-errors`
Fix argument ABI for overaligned structs on ppc64le
When passing a 16 (or higher) aligned struct by value on ppc64le, it needs to be passed as an array of `i128` rather than an array of `i64`. This will force the use of an even starting doubleword.
For the case of a 16 byte struct with alignment 16 it is important that `[1 x i128]` is used instead of `i128` -- apparently, the latter will get treated similarly to `[2 x i64]`, not exhibiting the correct ABI. Add a `force_array` flag to `Uniform` to support this.
The relevant clang code can be found here:
fe2119a7b0/clang/lib/CodeGen/Targets/PPC.cpp (L878-L884)fe2119a7b0/clang/lib/CodeGen/Targets/PPC.cpp (L780-L784)
I think the corresponding psABI wording is this:
> Fixed size aggregates and unions passed by value are mapped to as
> many doublewords of the parameter save area as the value uses in
> memory. Aggregrates and unions are aligned according to their
> alignment requirements. This may result in doublewords being
> skipped for alignment.
In particular the last sentence. Though I didn't find any wording for Clang's behavior of clamping the alignment to 16.
Fixes https://github.com/rust-lang/rust/issues/122767.
r? `@cuviper`
Implement minimal, internal-only pattern types in the type system
rebase of https://github.com/rust-lang/rust/pull/107606
You can create pattern types with `std::pat::pattern_type!(ty is pat)`. The feature is incomplete and will panic on you if you use any pattern other than integral range patterns. The only way to create or deconstruct a pattern type is via `transmute`.
This PR's implementation differs from the MCP's text. Specifically
> This means you could implement different traits for different pattern types with the same base type. Thus, we just forbid implementing any traits for pattern types.
is violated in this PR. The reason is that we do need impls after all in order to make them usable as fields. constants of type `std::time::Nanoseconds` struct are used in patterns, so the type must be structural-eq, which it only can be if you derive several traits on it. It doesn't need to be structural-eq recursively, so we can just manually implement the relevant traits on the pattern type and use the pattern type as a private field.
Waiting on:
* [x] move all unrelated commits into their own PRs.
* [x] fix niche computation (see 2db07f94f44f078daffe5823680d07d4fded883f)
* [x] add lots more tests
* [x] T-types MCP https://github.com/rust-lang/types-team/issues/126 to finish
* [x] some commit cleanup
* [x] full self-review
* [x] remove 61bd325da19a918cc3e02bbbdce97281a389c648, it's not necessary anymore I think.
* [ ] ~~make sure we never accidentally leak pattern types to user code (add stability checks or feature gate checks and appopriate tests)~~ we don't even do this for the new float primitives
* [x] get approval that [the scope expansion to trait impls](https://rust-lang.zulipchat.com/#narrow/stream/326866-t-types.2Fnominated/topic/Pattern.20types.20types-team.23126/near/427670099) is ok
r? `@BoxyUwU`
In its first step of computing transmutability, `rustc_transmutability`
constructs a byte-level representation of type layout (`Tree`). Previously, this
representation was computed for ADTs by inspecting the ADT definition and
performing our own layout computations. This process was error-prone, verbose,
and limited our ability to analyze many types (particularly default-repr types).
In this PR, we instead construct `Tree`s from `rustc_target::abi::Layout`s. This
helps ensure that layout optimizations are reflected our analyses, and increases
the kinds of types we can now analyze, including:
- default repr ADTs
- transparent unions
- `UnsafeCell`-containing types
Overall, this PR expands the expressvity of `rustc_transmutability` to be much
closer to the transmutability analysis performed by miri. Future PRs will work
to close the remaining gaps (e.g., support for `Box`, raw pointers, `NonZero*`,
coroutines, etc.).
Stop exporting `TypeckRootCtxt` and `FnCtxt`.
While they have many convenient APIs, it is better to expose dedicated functions for them
noticed in #122213
Add consistency with phrases "meantime" and "mean time"
"mean time" is used in a few places while "meantime" is used everywhere else; this would make usage consistent throughout the codebase.
The actual ABI implication here is that in some cases the values
are required to be "consecutive", i.e. must either all be passed
in registers or all on stack (without padding).
Adjust the code to either use Uniform::new() or Uniform::consecutive()
depending on which behavior is needed.
Then, when lowering this in LLVM, skip the [1 x i128] to i128
simplification if is_consecutive is set. i128 is the only case
I'm aware of where this is problematic right now. If we find
other cases, we can extend this (either based on target information
or possibly just by not simplifying for is_consecutive entirely).
When passing a 16 (or higher) aligned struct by value on ppc64le,
it needs to be passed as an array of `i128` rather than an array
of `i64`. This will force the use of an even starting register.
For the case of a 16 byte struct with alignment 16 it is important
that `[1 x i128]` is used instead of `i128` -- apparently, the
latter will get treated similarly to `[2 x i64]`, not exhibiting
the correct ABI. Add a `force_array` flag to `Uniform` to support
this.
The relevant clang code can be found here:
fe2119a7b0/clang/lib/CodeGen/Targets/PPC.cpp (L878-L884)fe2119a7b0/clang/lib/CodeGen/Targets/PPC.cpp (L780-L784)
I think the corresponding psABI wording is this:
> Fixed size aggregates and unions passed by value are mapped to as
> many doublewords of the parameter save area as the value uses in
> memory. Aggregrates and unions are aligned according to their
> alignment requirements. This may result in doublewords being
> skipped for alignment.
In particular the last sentence.
Fixes https://github.com/rust-lang/rust/issues/122767.
Save/restore more items in cache with incremental compilation
Right now they don't play very well together, consider a simple example:
```
$ export RUSTFLAGS="--emit asm"
$ cargo new --lib foo
Created library `foo` package
$ cargo build -q
$ touch src/lib.rs
$ cargo build
error: could not copy
"/path/to/foo/target/debug/deps/foo-e307cc7fa7b6d64f.4qbzn9k8mosu50a5.rcgu.s"
to "/path/to/foo/target/debug/deps/foo-e307cc7fa7b6d64f.s":
No such file or directory (os error 2)
```
Touch triggers the rebuild, incremental compilation detects no changes (yay) and everything explodes while trying to copy files were they should go.
This pull request fixes it by copying and restoring more files in the incremental compilation cache
Fixes https://github.com/rust-lang/rust/issues/89149
Fixes https://github.com/rust-lang/rust/issues/88829
Related: https://internals.rust-lang.org/t/interaction-between-incremental-compilation-and-emit/20551
Fix incorrect 'llvm_target' value used on watchOS target
## Issue
`xcodebuild -create-xcframework` command doesn't recognize static libraries that are built on "arm64_32-apple-watchos" target.
Here are steps to reproduce the issue on a Mac:
1. Install nightly toolchain `nightly-2024-03-27`. Needs this specific version, because newer nightly versions are broken on watchos target.
1. Create an empty library: `mkdir watchos-lib && cd watchos-lib && cargo init --lib`.
1. Add configuration `lib.crate-type=["staticlib"]` to Cargo.toml.
1. Build the library: `cargo +nightly-2024-03-27 build --release -Zbuild-std --target arm64_32-apple-watchos`
1. Run `xcodebuild -create-xcframework` to put the static library into a xcframework, which results in an error:
```
$ xcodebuild -create-xcframework -library target/arm64_32-apple-watchos/release/libwatchos_lib.a -output test.xcframework
error: unable to determine the platform for the given binary '.../watchos-lib/target/arm64_32-apple-watchos/release/libwatchos_lib.a'; check your deployment version settings
```
## Fix
The root cause of this error is `xcodebuild` couldn't read `LC_BUILD_VERSION` from the static library to determine the library's target platform. And the reason it's missing is that an incorrect `llvm_target` value is used in `arm64_32-apple-watchos` target. The expected value is `<arch>-apple-watchos<major>.<minor>.0`, i.e. "arm64_32-apple-watchos8.0.0".
The [.../apple/mod.rs](43f4f2a3b1/compiler/rustc_target/src/spec/base/apple/mod.rs (L321)) file contains functions that construct such string. There is an existing function `watchos_sim_llvm_target` which returns llvm target value for watchOS simulator. But there is none for watchOS device. This PR adds that missing function to align watchOS with other Apple platform targets.
To verify the fix, you can simply build a toolchain on this PR branch and repeat the steps above using the built local toolchain to verify the `xcodebuild -create-xcframework` command can create a xcframework successfully.
Furthermore, you can verify `LC_BUILD_VERSION` contains correct info by using the simple shell script below to print `LC_BUILD_VERSION` of the static library that's built on watchos target:
```shell
bin=target/arm64_32-apple-watchos/release/libwatchos_lib.a
file=$(ar -t "$bin" | grep -E '\.o$' | head -n 1)
ar -x "$bin" "$file"
vtool -show-build-version "$file"
```
Here is an example output from my machine:
```
watchos_rust-495d6aaf3bccc08d.watchos_rust.35ba42bf9255ca9d-cgu.0.rcgu.o:
Load command 1
cmd LC_BUILD_VERSION
cmdsize 24
platform WATCHOS
minos 8.0
sdk n/a
ntools 0
```
Remove sharding for VecCache
This sharding is never used (per the comment in code). If we re-add sharding at some point in the future this is cheap to restore, but for now no need for the extra complexity.
Add a debug asserts call to match_projection_projections to ensure invariant
Small nit as follow up of #123471.
r? `@compiler-errors`
`@bors` rollup=always
This sharding is never used (per the comment in code). If we re-add
sharding at some point in the future this is cheap to restore, but for
now no need for the extra complexity.
Rollup of 7 pull requests
Successful merges:
- #123294 (Require LLVM_CONFIG to be set in rustc_llvm/build.rs)
- #123467 (MSVC targets should use COFF as their archive format)
- #123498 (explaining `DefKind::Field`)
- #123519 (Improve cfg and check-cfg configuration)
- #123525 (CFI: Don't rewrite ty::Dynamic directly)
- #123526 (Do not ICE when calling incorrectly defined `transmute` intrinsic)
- #123528 (Hide async_gen_internals from standard library documentation)
r? `@ghost`
`@rustbot` modify labels: rollup
CFI: Don't rewrite ty::Dynamic directly
Now that we're using a type folder, the arguments in predicates are processed automatically - we don't need to descend manually.
We also want to keep projection clauses around, and this does so.
r? `@compiler-errors`
Improve cfg and check-cfg configuration
This PR improves cfg and check-cfg configuration by:
1. Extracting both logic under a common module (to improve the connection between the two)
2. Adding more documentation, in particular some steps when adding a new cfg
I also added my-self as mention in our triagebot conf for the new module.
Inspired by https://github.com/rust-lang/rust/pull/123411#discussion_r1554056681
MSVC targets should use COFF as their archive format
While adding support for Arm64EC I ran into an issue where the standard library's rlib was missing the "EC Symbol Table" which is required for the MSVC linker to find import library symbols (generated by Rust's `raw-dylib` feature) when building for EC.
The root cause of the issue is that LLVM only generated symbol tables (including the EC Symbol Table) if the `ArchiveKind` is `COFF`, but the MSVC targets didn't set their archive format, so it was defaulting to GNU.
Require LLVM_CONFIG to be set in rustc_llvm/build.rs
This environment variable should always be set by bootstrap in `rustc_llvm_env`. The fallback is quite ugly and complicated, so removing it is nice.
bf71daedc2/src/bootstrap/src/core/build_steps/compile.rs (L1166)
I tried finding when this was added in git history, but it pointed all the way to "add build scripts" at which point I stopped digging more. This has always been here.
cc `@nikic` `@cuviper` in case you happen to be aware of a deeper reason behind this
r? bootstrap
Check def id before calling `match_projection_projections`
When I "inlined" `assemble_candidates_from_predicates` into `for_each_item_bound` in #120584, I forgot to copy over the check that actually made sure the def id of the candidate was equal to the def id of the obligation. This means that we normalize goal a bit too often even if it's not productive to do so.
This PR adds that def id check back.
Fixes#123448
Now that we're using a type folder, the arguments in predicates are
processed automatically - we don't need to descend manually.
We also want to keep projection clauses around, and this does so.
CFI: Restore typeid_for_instance default behavior
Restore typeid_for_instance default behavior of performing self type erasure, since it's the most common case and what it does most of the time. Using concrete self (or not performing self type erasure) is for assigning a secondary type id, and secondary type ids are only assigned when they're unique and to methods, and also are only tested for when methods are used as function pointers.
Fix target-cpu fpu features on Arm R/M-profile
This is achieved by converting `+<fpu>,-d32,{,-fp64}` to `+<fpu>d16{,sp}`.
By using a single additive feature that captures `d16` vs `d32` and `sp` vs
`dp`, we prevent `-<feature>` from overriding `-C target-cpu` at build time.
Remove extraneous `-fp16` from `armv7r` targets, as this is not included in
`vfp3` anyway, but was preventing `fp16` from being enabled by e.g.,
`-C target-cpu=cortex-r7`, which does support `fp16`.
Add aarch64-apple-visionos and aarch64-apple-visionos-sim tier 3 targets
Introduces `aarch64-apple-visionos` and `aarch64-apple-visionos-sim` as tier 3 targets. This allows native development for the Apple Vision Pro's visionOS platform.
This work has been tracked in https://github.com/rust-lang/compiler-team/issues/642. There is a corresponding `libc` change https://github.com/rust-lang/libc/pull/3568 that is not required for merge.
Ideally we would be able to incorporate [this change](https://github.com/gimli-rs/object/pull/626) to the `object` crate, but the author has stated that a release will not be cut for quite a while. Therefore, the two locations that would reference the xrOS constant from `object` are hardcoded to their MachO values of 11 and 12, accompanied by TODOs to mark the code as needing change. I am open to suggestions on what to do here to get this checked in.
# Tier 3 Target Policy
At this tier, the Rust project provides no official support for a target, so we place minimal requirements on the introduction of targets.
> 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.)
See [src/doc/rustc/src/platform-support/apple-visionos.md](e88379034a/src/doc/rustc/src/platform-support/apple-visionos.md)
> 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.
> * 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.
> * If possible, use only letters, numbers, dashes and underscores for the name. Periods (.) are known to cause issues in Cargo.
This naming scheme matches `$ARCH-$VENDOR-$OS-$ABI` which is matches the iOS Apple Silicon simulator (`aarch64-apple-ios-sim`) and other Apple targets.
> 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 target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (`MIT OR Apache-2.0`).
> - 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 besubject to any new license requirements.
> - 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.
> - "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.
This contribution is fully available under the standard Rust license with no additional legal restrictions whatsoever. This PR does not introduce any new dependency less permissive than the Rust license policy.
The new targets do not depend on proprietary libraries.
> 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.
This new target mirrors the standard library for watchOS and iOS, with minor divergences.
> 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.
Documentation is provided in [src/doc/rustc/src/platform-support/apple-visionos.md](e88379034a/src/doc/rustc/src/platform-support/apple-visionos.md)
> 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.
> * 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.
> 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.
> * 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.
> 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.
> * 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 acknowledge these requirements and intend to ensure that they are met.
This target does not touch any existing tier 2 or tier 1 targets and should not break any other targets.
