---
# System prepended metadata

title: 2023 Q1 P-high review (2023-10-03 meeting)
tags: [' rustc', steering]

---

---
title: 2023 Q1 P-high review (2023-10-03 meeting)
tags: steering, rustc
---

# P-high review 2023 (Q1)

## Proposed Agenda

* Review the issue with no team, make sure they have one
* Review the T-compiler P-high issues with no WG assigned, try to identify a WG to own them
    * If that fails, but they do have an *active* owner, then tag with WG-none.
* Choose a category of remaining issues to review for rest of meeting
    * e.g. A-linkage? A-LLVM? A-codegen? A-lifetimes?

    
[P-high issues w/o T-* label]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AP-high+-label%3AT-cargo+-label%3AT-community+-label%3AT-compiler+-label%3AT-core+-label%3AT-crates-io+-label%3AT-dev-tools+-label%3AT-docs-rs+-label%3AT-infra+-label%3AT-libs+-label%3AT-libs-api+-label%3AT-release+-label%3AT-release+-label%3AT-rustdoc+-label%3AT-style+-label%3AT-types


## Missing team label

[P-high issues without team label][P-high issues w/o T-* label]

* "Pretty Printing on *-windows-gnu broken because .debug_gdb_scripts is not emitted" #25229
  - now tagged with T-compiler and wg-debugging


## P-high T-compiler missing owner (WG or assignee)

### No WG nor assignee

[P-high T-compiler issues without any working group nor individual assignee (and unnominated for any team)][P-high T-compiler w/o WG nor assignee]


(21 such issues)

* Our goal for each of these is to assign a WG label, preferably for a WG that we expect to triage issues and try to work through backlog.

**MOVE THE CURSOR BELOW AS WE GO THROUGH THE MEETING**

(the idea is that we take notes as we go through, but we avoid cut-and-pasting anything larger than a short line.)




#### "Codegen weirdness for sum of count_ones over an array" #101060 

* no change; we continue to monitor https://github.com/llvm/llvm-project/issues/57476 as the expected fix for this


#### "extern "C" functions don't generate the same IR definitions as clang on x86, causing problems with cross-language LTO" #102174 

* [left comment](https://github.com/rust-lang/rust/issues/102174#issuecomment-1614763994)
* did not identify owner/wg to adopt this; seems like a short-coming for us



#### "Massive performance regression between nightly-2022-08-12 and nightly-2022-08-13" #102952 

* explicit feature request for proper tail calls
* [left comment](https://github.com/rust-lang/rust/issues/102952#issuecomment-1614785206)
* downgraded from P-high to P-medium


#### "crate fails to compile release build (v1.65+) with rustc crashing" #106555 

* fixed in 1.67.0
* [left comment](https://github.com/rust-lang/rust/issues/106555#issuecomment-1614805170)
* closed as fixed

#### "Exponential (?) time complexity in evaluate_trait_predicate_recursively in rustdoc when proving Send/Sync" #106930 

* rustdoc specific
* oli-obk took ownership



#### "Memory sanitizer : false positive regression in nightly-2023-01-18"  #107149 

* left comment re-raising RalfJ point about why the presence/absence of the `noundef` attribute should matter if the body is *indeed* noundef.

#### "[ICE]: compiler segfault with GAT" #107366 

* re-assigned to T-types

**THIS IS THE CURSOR**


#### "Miscompilation: Equal pointers comparing as unequal" #107975 

* behavior has changed in recent releases: pointer comparison itself may be (more) deterministic now.
* but printing result of integer comparison remains non-deterministic
* still blocked on LLVM's end, with issue: https://github.com/llvm/llvm-project/issues/45725

#### "impl Trait lifetimes regression 1.67" #108591 

* already closed

#### "impl Trait lifetimes regression 1.67 part 2" #108592

* reassigning to T-types

### Discussed on [2023-03-03](https://rust-lang.zulipchat.com/#narrow/stream/238009-t-compiler.2Fmeetings/topic/.5Bsteering.5D.202023-03-03.20P-high.20review.20.20compiler-team.23590/near/339368981)



#### Error reporting from attribute macros regressed in 1.46.0 [#76360]

[#76360]: https://github.com/rust-lang/rust/issues/76360

* assigned to wg-diagnostics

#### "Linking with LLD fails (on Windows) but only in 32-bit (due to space in path)" [#78686]

[#78686]: https://github.com/rust-lang/rust/issues/78686

* left comment proposing downgrade to P-medium due to lack of interest

#### "Passing -C panic=abort still attempts to link in libunwind when targeting i686-pc-windows-gnu on v1.44+ [#79609]

[#79609]: https://github.com/rust-lang/rust/issues/79609

* left comment proposing doc update to explain the standard workarounds here

#### "rustc has wrong signature for C function with 16-byte aligned stack argument in x86_64 Linux" [#80127]

[#80127]: https://github.com/rust-lang/rust/issues/80127

* left comment asking PR author for [#103830][] if they will have time in near future to address review feedback

[#103830]: https://github.com/rust-lang/rust/issues/103830

#### "auto trait candidate selection is unsound" [#84857][]

[#84857]: https://github.com/rust-lang/rust/issues/84857

* left comment asking if resolving this is inherently blocked by the new trait solver ([#107374][])

[#107374]: https://github.com/rust-lang/rust/issues/107374

#### "A Pin unsoundness involving an impl DerefMut for Pin<&dyn LocalTrait>" [#85099][]

[#85099]: https://github.com/rust-lang/rust/issues/85099

* nominated for T-types discussion based on input from withoutboats

### Discussed on [2023-04-14](https://rust-lang.zulipchat.com/#narrow/stream/238009-t-compiler.2Fmeetings/topic/.5Bsteering.5D.202023-04-14.20P-high.20review.20.20compiler-team.23590/near/349393792)



#### "Rustc passes syntactically invalid input to attribute macros" #90256 

* assigned to WG-diagnostics

#### "Long-running const-eval (loops) unusable in practice."  #93481 

* downgraded to P-medium


#### "rustc 1.59/1.60 builds musl binaries that segfault, when compiling with musl-gcc wrappers, due to static-pie default" #95926 

* a detect+diagnostic strategy is acceptable here
* tagged with E-help-wanted, E-easy, E-mentor, and assigned pnkfelix as the mentor.


#### "How should we expose atomic load/store on targets that don't support full atomics" #99668 

* Not clear on who best to own this, especially if the main work remaining is to add support for `+forced-atomics` to a smorgasborg of LLVM targets.
* posted question for Amanieu and nikic to confirm that `+forced-atomics` support **is** the plan going forward.




#### "Double free on Linux with stable toolchain" #100914 

* treating as dupe of #83060
* we should "immediately" add a diagnostic warning when any one stack frame is larger than a certain threshold, simply based on all the miscellaenous code gen bugs we are seeing in this space. 


[WG-project-ffi-unwind]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+label%3AWG-project-ffi-unwind+sort%3Acreated-asc

[WG-incr-comp]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+label%3AWG-incr-comp+sort%3Acreated-asc

[WG-embedded]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+label%3AWG-embedded+sort%3Acreated-asc

[WG-diagnostics]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+label%3AWG-diagnostics+sort%3Acreated-asc

[WG-async]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+label%3AWG-async+sort%3Acreated-asc




[P-high T-compiler w/o WG nor assignee]: https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+label%3AT-compiler+label%3AP-high+-label%3Awg-debugging+-label%3AWG-embedded+-label%3AWG-project-ffi-unwind+-label%3AWG-diagnostics+-label%3AWG-async+-label%3AWG-incr-comp+no%3Aassignee+sort%3Acreated-asc+-label%3AI-types-nominated+-label%3AI-lang-nominated+-label%3AI-compiler-nominated

[P-high T-compiler w/o WG]: https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+label%3AT-compiler+label%3AP-high+-label%3AWG-embedded+-label%3AWG-project-ffi-unwind+-label%3AWG-diagnostics+-label%3AWG-async+-label%3AWG-incr-comp+sort%3Acreated-asc

