Removing the unstable ptx linker flavor

[kjetilkjeka]

Proposal

Since the introduction of the llvm-bitcode-linker, it has become the recommended linker for nvptx64-nvidia-cuda in the official Rust documentation, and was later made the default linker.

While llvm-bitcode-linker is now the default and recommended choice for the nvptx64-nvidia-cuda target, there still exists an unstable PTX linker flavor that was used with rust-ptx-linker. Since the upstream rust-ptx-linker project has been broken since 2022 and is effectively unmaintained and unusable, it can be assumed that there are close to no users of this linker flavor.

Given that:

• llvm-bitcode-linker is the recommended solution and is actively maintained,
• rust-ptx-linker is no longer functional or maintained,
• and there are close to no rust-ptx-linker users,

I propose removing the unstable PTX linker flavor.

Note that this provides little direct benefit to Rust users and is primarily motivated by cleaning up obsolete infrastructure that no longer provides value.

Mentors or Reviewers

The actual engineering work is trivial, and I will do it. I have not asked yet, but I hope @ZuseZ4 will be available for review.

Process

The main points of the Major Change Process are as follows:

• File an issue describing the proposal.
• A compiler team member who is knowledgeable in the area can second by writing @rustbot second or kickoff a team FCP with @rfcbot fcp $RESOLUTION.
  • Refer to Proposals, Approvals and Stabilization docs for when a second is sufficient, or when a full team FCP is required.
• Once an MCP is seconded, the Final Comment Period begins.
  • Final Comment Period lasts for 10 days after all outstanding concerns are solved.
  • Outstanding concerns will block the Final Comment Period from finishing. Once all concerns are resolved, the 10 day countdown is restarted.
  • If no concerns are raised after 10 days since the resolution of the last outstanding concern, the MCP is considered approved.

You can read more about Major Change Proposals on forge.

[rustbot]

Important

This issue is not meant to be used for technical discussion. There is a Zulip stream for that.
Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.

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<description of the concern>

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cc @rust-lang/compiler

[bjorn3]

@rustbot second

[LegNeato]

Fine from a rust-cuda and rust-gpu standpoint.

[rustbot]

The final comment period is now complete, this major change is now accepted. 🎉

As the automated representative, I want to express gratitude to the author for their work and everyone else who contributed to this major change proposal.

If you think this major change shouldn't have been accepted, feel free to remove the major-change-accepted label and reopen this issue.

Note

Further progress is now tracked over at rust-lang/rust#156954.