---
# System prepended metadata

title: T-compiler Meeting Agenda 2023-04-13
tags: [' rustc', weekly]

---

---
tags: weekly, rustc
---

# T-compiler Meeting Agenda 2023-04-13

## Announcements

- Next week Thu April, 20th - Rust stable release 1.69.0!
- [Types team meeting](https://www.google.com/calendar/event?eid=MTg3MDhpdTc3YXBqMGMzbnNxanUwdWZnazhfMjAyMzA0MTdUMTQwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-04-17T10:00:00-04:00>
- Reminder: if you see a PR/issue that seems like there might be legal implications due to copyright/IP/etc, please let the Core team know (or at least message @_**pnkfelix** or @_**Wesley Wiser** so we can pass it along).

### Other WG meetings ([calendar link](https://calendar.google.com/calendar/embed?src=6u5rrtce6lrtv07pfi3damgjus%40group.calendar.google.com))
- [wg-async weekly](https://www.google.com/calendar/event?eid=N211N3RrYzVqcnVvNnBycGFrcW9mcjNocTNfMjAyMzA0MTNUMTYwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-04-13T12:00:00-04:00>
- [wg-debugging triage meeting](https://www.google.com/calendar/event?eid=NjAwbDEwNzNmMzVsNDZucnFsdDdwbGJrdDRfMjAyMzA0MTdUMTQwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-04-17T10:00:00-04:00>
- [wg-rls-2.0 weekly sync-up](https://www.google.com/calendar/event?eid=MXJnbzBscDExNHJjNmVsdGhsaW8xcDljMmdfMjAyMzA0MTdUMTUwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-04-17T11:00:00-04:00>

## MCPs/FCPs

- New MCPs (take a look, see if you like them!)
  - "Disallow incoherent cfgs" [compiler-team#610](https://github.com/rust-lang/compiler-team/issues/610) 
  - "Integrate Enzyme into nightly rustc" [compiler-team#611](https://github.com/rust-lang/compiler-team/issues/611) 
  - "2024: Decrease debuginfo generated by  `-Cdebuginfo=1`" [compiler-team#613](https://github.com/rust-lang/compiler-team/issues/613) 
- Old MCPs (stale MCP might be closed as per [MCP procedure](https://forge.rust-lang.org/compiler/mcp.html#when-should-major-change-proposals-be-closed))
  - None at this time
- Old MCPs (not seconded, take a look)
  - "Rustc Contributor Program Major Change Proposal" [compiler-team#557](https://github.com/rust-lang/compiler-team/issues/557) (last review activity: 3 months ago)
  - "`needs_drop` as an auto trait" [compiler-team#575](https://github.com/rust-lang/compiler-team/issues/575) (last review activity: 3 months ago)
  - "Synthetic Partial Drop Glue" [compiler-team#585](https://github.com/rust-lang/compiler-team/issues/585) (last review activity: 2 months ago)
  - "Add New Values To MIPS_ALLOWED_FEATURES" [compiler-team#595](https://github.com/rust-lang/compiler-team/issues/595) (last review activity: about 20 days ago)
  - "Take MIR `Analysis` by `&mut`" [compiler-team#598](https://github.com/rust-lang/compiler-team/issues/598) (last review activity: about 20 days ago)
  - "-C linker-flavor=clang" [compiler-team#601](https://github.com/rust-lang/compiler-team/issues/601) (last review activity: about 20 days ago)
  - "Add `TyCtxt` wrappers to sort its methods into groups and improve documentation" [compiler-team#603](https://github.com/rust-lang/compiler-team/issues/603) (last review activity: about 20 days ago)
  - "Stable -C binary-dep-depinfo flag" [compiler-team#604](https://github.com/rust-lang/compiler-team/issues/604) (last review activity: about 20 days ago)
- Pending FCP requests (check your boxes!)
  - "Tracking Issue for `debugger_visualizer`" [rust#95939](https://github.com/rust-lang/rust/issues/95939#issuecomment-1496371829)
  - "Add deployment-target --print flag for Apple targets" [rust#105354](https://github.com/rust-lang/rust/pull/105354#issuecomment-1354546850)
  - "Update the version of musl used on `*-linux-musl` targets to 1.2.3" [rust#107129](https://github.com/rust-lang/rust/pull/107129#issuecomment-1407200120)
  - "Stabilize raw-dylib, link_ordinal, import_name_type and -Cdlltool" [rust#109677](https://github.com/rust-lang/rust/pull/109677#issuecomment-1491574659)
- Things in FCP (make sure you're good with it)
  - "Add builtin# for compiler-intrinsic syntax" [compiler-team#580](https://github.com/rust-lang/compiler-team/issues/580) 
  - "Clone "copyables" using copy codegen" [compiler-team#588](https://github.com/rust-lang/compiler-team/issues/588) 
  - "New tier-2 target for `wasm32-wasi-preview2`" [compiler-team#594](https://github.com/rust-lang/compiler-team/issues/594) 
  - "Add `force` option for `--extern` flag" [compiler-team#605](https://github.com/rust-lang/compiler-team/issues/605) 
  - "Rename `wasm32-wasi` target to `wasm32-wasi-preview1`" [compiler-team#607](https://github.com/rust-lang/compiler-team/issues/607) 
  - "Increase `TypeId`'s hash from 64 bits to 128 bits." [compiler-team#608](https://github.com/rust-lang/compiler-team/issues/608) 
  - "Add a `--print=unmap-path-prefixes` flag" [compiler-team#612](https://github.com/rust-lang/compiler-team/issues/612) 
  - "Evaluate place expression in `PlaceMention`" [rust#104844](https://github.com/rust-lang/rust/pull/104844) 
- Accepted MCPs
  - No new accepted proposals this time.
- Finalized FCPs (disposition merge)
  - No new finished FCP (disposition merge) this time.

### WG checkins

- @_*WG-rustc-dev-guide* by @**Santiago Pastorino** and @**Yuki Okushi|217081** ([previous checkin](https://hackmd.io/4CKNflTQQIKOxk7jiuh7NQ#WG-checkins))
  > #### Most notable changes
  > 
  > - Reorganize "Getting Started" and add a "What should I work on?" section [#1665](https://github.com/rust-lang/rustc-dev-guide/pull/1665)
  > - Consolidate, deduplicate, and link information for getting started [#1653](https://github.com/rust-lang/rustc-dev-guide/pull/1653)
  > - Add chapter on fuzzing [#1646](https://github.com/rust-lang/rustc-dev-guide/pull/1646)
  > - Update rustdoc-internals.md [#1644](https://github.com/rust-lang/rustc-dev-guide/pull/1644)
  > - Update labels overview [#1639](https://github.com/rust-lang/rustc-dev-guide/pull/1639)
  > 
  > #### Most notable WIPs
  > 
  > - docs: document new `suggest-tests` tool [#1660](https://github.com/rust-lang/rustc-dev-guide/pull/1660)
  > - Add documentation for RUSTC_EMIT [#1635](https://github.com/rust-lang/rustc-dev-guide/pull/1635)
  > - new chapter with examples of diagnostic translation PRs [#1621](https://github.com/rust-lang/rustc-dev-guide/pull/1621)
  > - Add back the `canonicalization` chapter. [#1532](https://github.com/rust-lang/rustc-dev-guide/pull/1532)
  > - Improve documentation of MIR queries & passes [#1434](https://github.com/rust-lang/rustc-dev-guide/pull/1434)
  > - Document inert vs active attributes [#1110](https://github.com/rust-lang/rustc-dev-guide/pull/1110)

- Impl Trait initiative by @**oli** ([prev. checkin](https://hackmd.io/Y3MpcGIXRuKpDGmYZV-TJg#WG-checkins))
  > The TAIT stabilization has been stopped. We split the feature gate into two: one for `impl Trait` in associated types and one for `impl Trait` in type aliases. Both features will get developed independently. Simultaneously we're rewriting the entire internal implementation to be able to support it with the new solver.

## Backport nominations

[T-compiler stable](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Abeta-nominated+-label%3Abeta-accepted+label%3AT-compiler) / [T-compiler beta](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Astable-nominated+-label%3Astable-accepted+label%3AT-compiler)
- :beta: [1.69.0] "Revert "Don't recover lifetimes/labels containing emojis as character literals"" [rust#110135](https://github.com/rust-lang/rust/pull/110135) 
  - PR and nomination from @**Michael Goulet (compiler-errors)**
  - Reverts PR [#108031](https://github.com/rust-lang/rust/pull/108031) (decided to not backport #109754, [comment](https://github.com/rust-lang/rust/pull/109754#issuecomment-1490452045))
  - Beta cut is tomorrow (IIRC)
<!--
/poll Approve beta backport of #110135?
approve
decline
don't know
-->
- No stable nominations for `T-compiler` this time.

[T-rustdoc stable](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Abeta-nominated+-label%3Abeta-accepted+label%3AT-rustdoc) / [T-rustdoc beta](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Astable-nominated+-label%3Astable-accepted+label%3AT-rustdoc)
- No beta nominations for `T-rustdoc` this time.
- No stable nominations for `T-rustdoc` this time.

:back: / :shrug: / :hand:

## PRs S-waiting-on-team

[T-compiler](https://github.com/rust-lang/rust/pulls?q=is%3Aopen+label%3AS-waiting-on-team+label%3AT-compiler)
- "Enforce that `closure: 'a` requires that `closure_ret_ty: 'a` holds" [rust#84385](https://github.com/rust-lang/rust/pull/84385)
  - note for @t-types: is this issue a bit stuck? ([comment](https://github.com/rust-lang/rust/pull/84385#issuecomment-1472110629))
- "More distinctive pretty-printing of function item types" [rust#99927](https://github.com/rust-lang/rust/pull/99927)
  - @**Jack Huey** unblocked, so `S-looking-for-consensus`? :-)
- Other issues [in progress or waiting on other teams](https://hackmd.io/XYr1BrOWSiqCrl8RCWXRaQ)

### Oldest PRs waiting for review

[T-compiler](https://github.com/rust-lang/rust/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-asc+label%3AS-waiting-on-review+draft%3Afalse+label%3AT-compiler)
- "Fix off-by-one error in X87DoubleExtended::from_bits" [rust#100685](https://github.com/rust-lang/rust/pull/100685) (last review activity: 7 months ago)
  - ping @**Wesley Wiser** 
- "Support AIX-style archive type" [rust#106704](https://github.com/rust-lang/rust/pull/106704) (last review activity: 3 months ago)
  - hasn't this been r+ed by @_**bjorn3** ? ([comment](https://github.com/rust-lang/rust/pull/106704#issuecomment-1499013882))
  - maybe switch to author to fix the tests?
- "Update the version of musl used on `*-linux-musl` targets to 1.2.3" [rust#107129](https://github.com/rust-lang/rust/pull/107129) (last review activity: 2 months ago)
  - Reminder: this is waiting on RFC ([comment](https://github.com/rust-lang/rust/pull/107129#issuecomment-1407200120))
- "suggest lifetime for closure parameter type when mismatch" [rust#105888](https://github.com/rust-lang/rust/pull/105888) (last review activity: 2 months ago)
  - ping @**Michael Goulet (compiler-errors)** 

## Issues of Note

### Short Summary

- [1 T-compiler P-critical issues](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-critical)
  - [1 of those are unassigned](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-critical+no%3Aassignee)
- [65 T-compiler P-high issues](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high)
  - [33 of those are unassigned](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high+no%3Aassignee)
- [0 P-critical, 0 P-high, 4 P-medium, 0 P-low regression-from-stable-to-beta](https://github.com/rust-lang/rust/labels/regression-from-stable-to-beta)
- [0 P-critical, 2 P-high, 3 P-medium, 1 P-low regression-from-stable-to-nightly](https://github.com/rust-lang/rust/labels/regression-from-stable-to-nightly)
- [1 P-critical, 37 P-high, 92 P-medium, 13 P-low regression-from-stable-to-stable](https://github.com/rust-lang/rust/labels/regression-from-stable-to-stable)

### P-critical

[T-compiler](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-compiler)
- "Wrong discriminant read with uninhabited variants" [rust#110128](https://github.com/rust-lang/rust/issues/110128)
  - can be reproduced on stable ([comment](https://github.com/rust-lang/rust/issues/110128#issuecomment-1501529638))
  - @**cjgillot** authored PR [rust#110197](https://github.com/rust-lang/rust/pull/110197), review in progress
  - note: some perf. regressions to be reviewed but they look to be expected (see PR opening comment)

[T-types](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-types)
- No `P-critical` issues for `T-types` at this time.

[T-rustdoc](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-rustdoc)
- No `P-critical` issues for `T-rustdoc` at this time.

### P-high regressions

[P-high beta regressions](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3Aregression-from-stable-to-beta+label%3AP-high+-label%3AT-infra+-label%3AT-libs+-label%3AT-libs-api+-label%3AT-release+-label%3AT-rustdoc+-label%3AT-core)
- No `P-high` beta regressions this time.

[Unassigned P-high nightly regressions](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3Aregression-from-stable-to-nightly+label%3AP-high+no%3Aassignee+-label%3AT-infra+-label%3AT-libs+-label%3AT-libs-api+-label%3AT-release+-label%3AT-rustdoc+-label%3AT-core+)
- "const-propagated `arithmetic_overflow` in unreachable code" [rust#109731](https://github.com/rust-lang/rust/issues/109731)
  - issue was reopened, new PR in progress is up [rust#110107](https://github.com/rust-lang/rust/pull/110107)
  - unsure if it will close the issue (see [conversation](https://github.com/rust-lang/rust/issues/109731#issuecomment-1500664283))
- "windows-gnu thin-lto test linking error regression" [rust#109797](https://github.com/rust-lang/rust/issues/109797)
  - left open as it will `E-needs-test` and to act as magnet for further regressions being filed until #109806 lands ([comment](https://github.com/rust-lang/rust/issues/109797#issuecomment-1499205307))

## Performance logs

N/A for this week

## Nominated Issues

[T-compiler](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AI-compiler-nominated)
- No I-compiler-nominated this time.

[RFC](https://github.com/rust-lang/rfcs/issues?q=is%3Aopen+label%3AI-compiler-nominated)
- No I-compiler-nominated RFCs this time.

## Next week's WG checkins

- @_*WG-llvm* by @**nagisa** and @**Nikita Popov**
- Types team by @**nikomatsakis** and @**Jack Huey**

Agenda draft: https://hackmd.io/8Wy81OhVQ06VG2px9R1eSA
