LoongArch: Fix direct-access-external-data test
On LoongArch targets, `-Cdirect-access-external-data` defaults to `no`. Since copy relocations are not supported, `dso_local` is not emitted under `-Crelocation-model=static`, unlike on other targets.
Fix suppression of `unused_assignment` in binding of `unused_variable`
Unused assignments to an unused variable should trigger only the `unused_variables` lint and not also the `unused_assignments` lint. This was previously implemented by checking whether the span of the assignee was within the span of the binding pattern, however that failed to capture situations was imported from elsewhere (eg from the input tokenstream of a proc-macro that generates the binding pattern).
By comparing the span of the assignee to those of the variable introductions instead, a reported stable-to-stable regression is resolved.
This fix also impacted some other preexisting tests, which had (undesirably) been triggering both the `unused_variables` and `unused_assignments` lints on the same initializing assignment; those tests have therefore now been updated to expect only the former lint.
Fixesrust-lang/rust#151514
r? cjgillot (as author of reworked liveness testing in rust-lang/rust#142390)
The SSE2 helper function is not inlined across crate boundaries,
so we cannot verify the codegen in an assembly test. The fix is
still verified by the absence of performance regression.
Fix 'the the' typo in library/core/src/array/iter.rs
This PR fixes a small grammatical error in a safety comment within `library/core/src/array/iter.rs` where the word "the" was duplicated.
No functional changes.
Rename `DepKindStruct` to `DepKindVTable`
This type is used by dependency-tracking code in the query system, for looking up function pointers and other metadata associated with a particular `DepKind`.
Calling it “struct” is not particularly helpful, whereas calling it a “vtable” at least gives some basic intuition for what it is and how it is used.
Some associated identifiers have also drifted a bit over time, and this PR adjusts those as well.
There should be no change to compiler behaviour.
r? nnethercote (or compiler)
x86 soft-float feature: mark it as forbidden rather than unstable
I am not sure why I made it "unstable" in f755f4cd1a; I think at the time "forbidden" did not work for some reason.
Making it "forbidden" instead has no significant effect on `-Ctarget-feature` use, it just changes the warning. It *does* have the effect that one cannot query this using `cfg(target_feature)` on nightly any more, but that seems fine to me. It only ever worked as an accidental side-effect of f755f4cd1a anyway.
r? @workingjubilee
Various refactors to the proc_macro bridge
This reduces the amount of types, traits and other abstractions that are involved with the bridge, which should make it easier to understand and modify. This should also help a bit with getting rid of the type marking hack, which is complicating the code a fair bit.
Fixes: rust-lang/rust#139810
Fix(lib/win/thread): Ensure `Sleep`'s usage passes over the requested duration under Win7
Fixesrust-lang/rust#149935. See the added comment for more details.
This makes the concerned test now reproducibly pass, for us at least. Also, testing this separately revealed successful: see the issue.
@rustbot label C-bug I-flaky-test O-windows-7 T-libs A-time A-thread
add CSE optimization tests for iterating over slice
This PR is regression test for issue rust-lang/rust#119573.
This PR introduces a new regression test to verify a critical optimization known as Common Subexpression Elimination (CSE) is correctly applied during various slice iteration patterns.
std: avoid tearing `dbg!` prints
Fixes https://github.com/rust-lang/rust/issues/136703.
This is an alternative to rust-lang/rust#149859. Instead of formatting everything into a string, this PR makes multi-expression `dbg!` expand into multiple nested matches, with the final match containing a single `eprint!`. By using macro recursion and relying on hygiene, this allows naming every bound value in that `eprint!`.
CC @orlp
r? libs
abi: add a rust-preserve-none calling convention
This is the conceptual opposite of the rust-cold calling convention and is particularly useful in combination with the new `explicit_tail_calls` feature.
For relatively tight loops implemented with tail calling (`become`) each of the function with the regular calling convention is still responsible for restoring the initial value of the preserved registers. So it is not unusual to end up with a situation where each step in the tail call loop is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived and more like a conceptual inverse of `rust-cold`, but could not come with a great name (`rust-cold` is itself not a great name: cold in what context? from which perspective? is it supposed to mean that the function is rarely called?)
Fix cstring-merging test for Hexagon target
Hexagon assembler uses `.string` directive instead of `.asciz` for null-terminated strings. Both are equivalent but the test was only checking for `.asciz`.
Update the CHECK patterns to accept both directives using `.{{asciz|string}}` regex pattern.
Extend build-manifest local test guide
Fill in more blanks about how to test build-manifest changes with Rustup.
Figured this out while working on https://github.com/rust-lang/rust/pull/151156, with the help of bjorn3.
Add Korean translation to Rust By Example
Hello,
I’ve added a Korean translation file to Rust By Example.
This contribution will help Korean readers learn Rust more easily by providing localized explanations and examples.
Please review the proposed additions when you have time.
Thanks in advance for your time and review! 🙏
Add Korean translation. Thanks in advance.
std: `sleep_until` on Motor and VEX
This PR:
* Forwards the public `sleep_until` to the private `sleep_until` on Motor OS
* Adds a `sleep_until` implementation on VEX that yields until the deadline has passed
CC @lasiotus
CC @lewisfm @tropicaaal @Gavin-Niederman @max-niederman
compiletest: Make `aux-crate` directive explicitly handle `--extern` modifiers
With `-Zunstable-options` it is possible to pass options to `--extern`. See here for an exhaustive list of possible options:
b5dd72d292/compiler/rustc_session/src/config.rs (L2356-L2367)
Using these options works with the `aux-crate` directive, but only because the options pretend to be part of the name. Make it clearer what `aux-crate` supports by explicitly handling `--extern` options.
This PR is step one of splitting up https://github.com/rust-lang/rust/pull/151258 into smaller pieces.
r? @Zalathar
add `simd_splat` intrinsic
Add `simd_splat` which lowers to the LLVM canonical splat sequence.
```llvm
insertelement <N x elem> poison, elem %x, i32 0
shufflevector <N x elem> v0, <N x elem> poison, <N x i32> zeroinitializer
```
Right now we try to fake it using one of
```rust
fn splat(x: u32) -> u32x8 {
u32x8::from_array([x; 8])
}
```
or (in `stdarch`)
```rust
fn splat(value: $elem_type) -> $name {
#[derive(Copy, Clone)]
#[repr(simd)]
struct JustOne([$elem_type; 1]);
let one = JustOne([value]);
// SAFETY: 0 is always in-bounds because we're shuffling
// a simd type with exactly one element.
unsafe { simd_shuffle!(one, one, [0; $len]) }
}
```
Both of these can confuse the LLVM optimizer, producing sub-par code. Some examples:
- https://github.com/rust-lang/rust/issues/60637
- https://github.com/rust-lang/rust/issues/137407
- https://github.com/rust-lang/rust/issues/122623
- https://github.com/rust-lang/rust/issues/97804
---
As far as I can tell there is no way to provide a fallback implementation for this intrinsic, because there is no `const` way of evaluating the number of elements (there might be issues beyond that, too). So, I added implementations for all 4 backends.
Both GCC and const-eval appear to have some issues with simd vectors containing pointers. I have a workaround for GCC, but haven't yet been able to make const-eval work. See the comments below.
Currently this just adds the intrinsic, it does not actually use it anywhere yet.
Fix(lib/win/net): Remove hostname support under Win7
Fixesrust-lang/rust#150896. `GetHostNameW` is not available under Windows 7, leading to dynamic linking failures upon program executions. For now, as it is still unstable, this therefore appropriately cfg-gates the feature in order to mark the Win7 as unsupported with regards to this particular feature. Porting the functionality for Windows 7 would require changing the underlying system call and so more work for the immediate need.
@rustbot label C-bug O-windows-7 T-libs A-io
Add new Tier 3 targets for ARMv6
Adds three new targets to support ARMv6 processors running bare-metal:
* `armv6-none-eabi` - Arm ISA, soft-float
* `armv6-none-eabihf` - Arm ISA, hard-float
* `thumbv6-none-eabi` - Thumb-1 ISA, soft-float
There is no `thumbv6-none-eabihf` target because as far as I can tell, hard-float isn't support with the Thumb-1 instruction set (and you need the ARMv6T2 extension to enable Thumb-2 support).
The targets require ARMv6K as a minimum, which allows the two Arm ISA targets to have full CAS atomics. LLVM has a bug which means it emits some ARMv6K instructions even if you only call for ARMv6, and as no-one else has noticed the bug, and because basically all ARMv6 processors have ARMv6K, I think this is fine. The Thumb target also doesn't have any kind of atomics, just like the Armv5TE and Armv4 targets, because LLVM was emitting library calls to emulate them.
Testing will be added to https://github.com/rust-embedded/aarch32 once the target is accepted. I already have tests for the other non-M arm-none-eabi targets, and those tests pass on these 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.)
I have listed myself. If accepted, I'll talk to the Embedded Devices Working Group about adding this one to the rosta with all the others they support.
> 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.
You might prefer `arm-none-eabi`, because `arm-unknown-linux-gnu` is an ARMv6 target - the implicit rule seems to be that if the Arm architecture version isn't specified, it's assumed to be v6. However, `armv6-none-eabi` seemed to fit better between `armv5te-none-eabi` and `armv7a/armv7r-none-eabi`.
The hamming distance between `thumbv6-none-eabi` and `thumbv6m-none-eabi` is unfortunately low, but I don't know how to make it better. They *are* the ARMv6 and ARMv6-M targets, and its perhaps not worse than `armv7a-none-eabi` and `armv7r-none-eabi`.
> 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.
No different to any other arm-none-eabi target.
> 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.
Noted.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate...
Same as other arm-none-eabi targets.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible.
Same as other arm-none-eabi targets.
> 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.
Noted.
> 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.
Noted
> 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.)
Noted
Three targets, covering A32 and T32 instructions, and soft-float and
hard-float ABIs. Hard-float not available in Thumb mode. Atomics
in Thumb mode require __sync* functions from compiler-builtins.
This is the conceptual opposite of the rust-cold calling convention and
is particularly useful in combination with the new `explicit_tail_calls`
feature.
For relatively tight loops implemented with tail calling (`become`) each
of the function with the regular calling convention is still responsible
for restoring the initial value of the preserved registers. So it is not
unusual to end up with a situation where each step in the tail call loop
is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers
are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived
and more like a conceptual inverse of `rust-cold`, but could not come
with a great name (`rust-cold` is itself not a great name: cold in what
context? from which perspective? is it supposed to mean that the
function is rarely called?)
