Add new Tier-3 target: loongarch64-unknown-linux-musl

[heiher]

MCP: rust-lang/compiler-team#518

[rustbot]

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[rustbot]

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

[compiler-errors]

r? wesleywiser

[compiler-errors]

actually wait nvm i can review this lol

@bors r+ rollup

[bors]

📌 Commit d9fd432 has been approved by compiler-errors

It is now in the queue for this repository.

[wesleywiser]

@bors r-

[wesleywiser]

I don't recall seeing an acknowledgement for the target tier policy with regards to this target so could you please quote the corresponding requirements verbatim from the tier 3 target tier policy to explain how the target meets those requirements (leaving a new comment here is fine). You can find an example of this in the PR description for #86191. Thank you! 🙂

[heiher]

I don't recall seeing an acknowledgement for the target tier policy with regards to this target so could you please quote the corresponding requirements verbatim from the tier 3 target tier policy to explain how the target meets those requirements (leaving a new comment here is fine). You can find an example of this in the PR description for #86191. Thank you! 🙂

@wesleywiser Thanks. The proposal to add the loongarch64-linux-musl target (Tier 2) is already included in MCP 518, which leads me to believe that there's no need to create a new MCP for this target again. 😃 However, if I've misunderstood, I'm more than willing to supplement the MCP according to the target tier policy. What do you think?

[heiher]

I don't recall seeing an acknowledgement for the target tier policy with regards to this target so could you please quote the corresponding requirements verbatim from the tier 3 target tier policy to explain how the target meets those requirements (leaving a new comment here is fine). You can find an example of this in the PR description for #86191. Thank you! 🙂

@wesleywiser Thanks. The proposal to add the loongarch64-linux-musl target (Tier 2) is already included in MCP 518, which leads me to believe that there's no need to create a new MCP for this target again. 😃 However, if I've misunderstood, I'm more than willing to supplement the MCP according to the target tier policy. What do you think?

Okay. I rechecked MCP 518 and in fact it doesn't explain verbatim how the target meets requirements of target tier policy. I'll make it clear here. 😃

[heiher]

Target Tier Policy Acknowledgements

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.)

• WANG Rui - wangrui@loongson.cn @heiher
• WANG Xuerui - git@xen0n.name @xen0n

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	Descriptions
loongarch64-unknown-linux-musl	LoongArch 64-bit, LP64D ABI (kernel 5.19, musl 1.2.5)

ISA Docs

• LoongArch ELF psABI
• LoongArch Toolchain conventions

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.

Ack.

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.

There are no known legal issues or license incompatibilities.

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 discussion

Ack.

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.

Ack.

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.

Ack.

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.

Ack.

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.

Ack.

[wesleywiser]

Thanks @heiher, much appreciated!

@bors r+

[bors]

📌 Commit 8255618 has been approved by wesleywiser

It is now in the queue for this repository.

[heiher]

This will need rebase after #121905 is merged

Rebase done. Thanks.

@rustbot ready

[heiher]

@matthiaskrgr Request r+, Thanks.

[wesleywiser]

@bors r+

[bors]

📌 Commit 36d271f has been approved by wesleywiser

It is now in the queue for this repository.

[heiher]

@rustbot label: +relnotes

[RalfJung]

Turns out this was added in the tier 2 section, not the tier 3 section. That's pretty hard to see during review since the diff doesn't show the section header...

I wonder if there's something we can do here, like split the tables across multiple files?