Don't abort compilation after giving a lint error

[jyn514]

Proposal

Instead, continue to compile, and only exit with an error just before linking. The only reason to abort early is when the program is so broken that either:

1. later passes get confused and ICE
2. any diagnostics from later passes would be noise

This is never the case for lints, because the compiler has to be able to deal with allow-ed lints.
So it can continue to lint and compile even if there are lint errors. In particular, this shows all lints at once, which can currently be frustrating when deny(warnings) is set or you trip a deny-by-default lint.

This has been requested a few times by users; see rust-lang/rust#82761, rust-lang/rust#87334.

This has already been implemented in rust-lang/rust#87337 (modulo some test updates).

Mentors or Reviewers

@flip1995, @LeSeulArtichaut

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

[oli-obk]

@rustbot second

[apiraino]

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