Stable -C binary-dep-depinfo flag

[pnkfelix]

Proposal

Upgrade the existing -Z binary-dep-depinfo from an unstable -Z flag to a stable -C flag. The short-term goal is to expose this flag on stable Rust. Longer term, we can look into changing the default, as suggested in #464; this is just a stepping stone towards that goal.

The -Z binary-dep-depinfo flag currently has tracking issue: rust-lang/rust#63012, which lists two open blockers that may be relevant here:

• Canonicalized paths on Windows.
• Codegen backends are not tracked.

pnkfelix does not currently know whether either of those should be considered blockers for a -Z to -C upgrade. One can imagine treating both of the above as a "quality of implementation" issue that should not block stabilizing an otherwise useful flag for rust users.

One definite blocker for stabilizing this is that there are almost no tests of this functionality. The only test I could find under the tests/ directory is https://github.com/rust-lang/rust/tree/master/tests/run-make-fulldeps/hotplug_codegen_backend . I suspect coming up with suitable tests is going to be far more work than the -Z to -C upgrade here.

Mentors or Reviewers

I am willing to mentor this work.

Process

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

• File an issue describing the proposal.
• A compiler team member or contributor who is knowledgeable in the area can second by writing @rustbot second.
  • Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a -C flag, then full team check-off is required.
  • Compiler team members can initiate a check-off via @rfcbot fcp merge on either the MCP or the PR.
• Once an MCP is seconded, the Final Comment Period begins. If no objections are raised after 10 days, the MCP is considered approved.

You can read more about Major Change Proposals on forge.

Comments

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.

[rustbot]

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.

cc @rust-lang/compiler @rust-lang/compiler-contributors

[tmandry]

@rustbot second

[apiraino]

@rustbot label -final-comment-period +major-change-accepted

[apiraino]

I will reopen this proposal to reflect that the discussion is still ongoing, concerns need to be fleshed out

[rustbot]

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.

cc @rust-lang/compiler @rust-lang/compiler-contributors

[pnkfelix]

Withdrawing MCP to focus on answering the questions that were raised in the zulip thread about the path handling.