Add OpenHarmony targets

[Amanieu]

• aarch64-unknown-linux-ohos
• armv7-unknown-linux-ohos

Compiler team MCP: rust-lang/compiler-team#568

[rustbot]

r? @ehuss

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[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

These commits modify the Cargo.lock file. Random changes to Cargo.lock can be introduced when switching branches and rebasing PRs.
This was probably unintentional and should be reverted before this PR is merged.

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[workingjubilee]

I hate to be a pedantic bore about minor points of protocol that mostly don't really matter, but I was cursed at birth with an editor's eyes:

Recently, {arch}-fuchsia was changed to {arch}-unknown-fuchsia for Toolchain Reasons. Are we sure we want to skip the vendor "field" in this tuple?

[ehuss]

r? compiler

[Amanieu]

Recently, {arch}-fuchsia was changed to {arch}-unknown-fuchsia for Toolchain Reasons. Are we sure we want to skip the vendor "field" in this tuple?

I really don't feel too strongly about it. The C toolchain uses aarch64-linux-ohos but then again so do many toolchains for which we use -unknown. In the end it's just a naming thing and doesn't really matter.

[workingjubilee]

Yeah, I don't really care either, my only preference is against name churn. So I just wanted to ask if anyone had doublechecked that, as "C toolchain" might mean "Clang", and I don't know if the same rationales as in #106429 will or will not apply because I'm just another ignorant 外国人 who only heard of OpenHarmony today.

[Amanieu]

Updated to libc 0.2.140 which has OpenHarmony support. This is now ready for review.

The only remaining question is whether to name the targets *-linux-ohos or *-unknown-linux-ohos. The Clang toolchain uses *-linux-ohos but other Rust targets add -unknown- for an explicit vendor.

@tmandry @djkoloski Do you have any thoughts since the same issue came up with fuchsia?

[djkoloski]

In our case, we added vendor info to Fuchsia's triples to bring them in line with other triples. Clang actually supports both x86_64-fuchsia and x86_64-unknown-fuchsia, and IIRC it does so by parsing targets and filling in implied or default info. Rust just matches on the triple, which is less flexible. So if memory serves, clang should already support triples with and without vendor info for OpenHarmony.

Right now Rust still has the old set of Fuchsia triples (doubles) as an alias for the new ones (actual triples), but those are on the way out.

[tmandry]

To add to what @djkoloski said, we consider x86_64-unknown-fuchsia to be the "canonical" triple for both clang and now rustc. Consistency with other targets and across compilers (or frontend/backend) is desirable.

If rustc also supported dropping vendor info for any target where it's unknown that would be fine, but you would have to decide if you want to handle that in rustup and possibly other places. For now we just went with what's most consistent.

[Amanieu]

I've renamed the OpenHarmony targets to include a -unknown- vendor component. They are now consistent with the other Linux targets (except for Android).

@rustbot ready

[petrochenkov]

r=me after squashing commits.
@rustbot author

[Amanieu]

@bors r=petrochenkov

[bors]

📌 Commit e3968be has been approved by petrochenkov

It is now in the queue for this repository.

[bors]

⌛ Testing commit e3968be with merge f346fb0...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing f346fb0 to master...

[rust-timer]

Finished benchmarking commit (f346fb0): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.7%	[1.7%, 1.7%]	2
Regressions ❌ (secondary)	2.4%	[1.1%, 8.5%]	11
Improvements ✅ (primary)	-2.4%	[-2.4%, -2.4%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[-2.4%, 1.7%]	3

Cycles

This benchmark run did not return any relevant results for this metric.