Proposal

With rust-lang/rust#99015 landing, the typeck query is the only place using an FnCtxt and this should stay this way. HIR typeck is a fairly complex and self contained part of rustc and moving all of that in a separate, common place should make refactorings and cleanups easier. It should also be easier to understand and more difficult to misuse, as you would have to add a dependency on a new crate to use the FnCtxt now.

We should move the typeck queries, FnCtxt and anything else exclusively used by HIR typeck to a new crate rustc_hir_typeck.

At the same time I also suggest renaming rustc_typeck to rustc_hir_analysis as that crate is responsible for so much more than simply "checking types".

Mentors or Reviewers

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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.