---
# System prepended metadata

title: P-high review 2023 (Q4)

---

---
title: 2023 Q4 P-high review (2023-10-03 meeting)
tags: steering, rustc
---

# P-high review 2023 (Q4)

## 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]


- Performance regression in 1.72 related to normalization of opaques with late-bound vars [#115283](https://github.com/rust-lang/rust/issues/115283)
    - Still an issue although some users report significant improvements on nightly compilers. Other users are still seeing issues but not the 350x originally reported.
    - Still P-high
    - Assigned to WG-compiler-performance

- rustc 1.72.0 hangs on release build of the simple example in rfd crate [#115207](https://github.com/rust-lang/rust/issues/115207)
    - Closed since the fix has shipped in 1.72.1 and 1.73.

- unchecked region constraints for opaque types in dead code [#112417](https://github.com/rust-lang/rust/issues/112417)
    - Not much seems to have happened since the original report.
    - We think P-high is reasonable at this time.
    - Tagging T-types since this seems to be within their domain. They may also decide to re-evaluate the priority level.

- standalone installer rustc-1.70.0 (precompiled binary) segfaults in elf_machine_runtime_setup [#112286](https://github.com/rust-lang/rust/issues/112286)
    - Downgraded to P-medium as this issue is not really rustc or Rust related, it's an issue with binutils+BOLT and is being worked on upstream. The issue only manifests when stripping the BOLT'd binary which is not a configuration we support out of the box. Gentoo has adjusted their ebuild to avoid doing this so no one is currently blocked.


## 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]

- LNK1189 "library limit of 65535 obj exceeded" building rustc #53014
    - Assigned wesleywiser to follow up with sivadeilra .
    - Tagged wg-incr-comp as this issue is directly related to incremental compilation of the compiler itself.

- Passing -C panic=abort still attempts to link in libunwind when targeting i686-pc-windows-gnu on v1.44+ #79609
    - Assigned wesleywiser to add the issue and workarounds to i686-windows platform support documentation.
    - Will reduce to P-medium after that is complete.

- Regressions with large (2-4GB) stack arrays on large stacks #83060
    - Labeling as wg-diagnostics for the "large stack frame" diagnostic and wg-llvm for the fix in LLVM for bad code generation

- Undefined reference to getauxval in function init_have_lse_atomics when compiling to nightly aarch64-unknown-linux-musl #89626
    - P-high still feels appropriate as this is blocking use of arm64-linux-musl for various projects.
    - No relevant teams or WGs :( 
    - @pnkfelix offered to investigate why `-lc` appears in a different position for musl than glibc.

- Linking with LLD fails (on Windows) but only in 32-bit (due to space in path)
#78686
    - lqd attempted repro but could not confirm the issue existed
    - Closing since we currently believe this to be resolved
    
- rustc 1.59/1.60 builds musl binaries that segfault, when compiling with musl-gcc wrappers, due to static-pie default #95926
    - Still repros, also still getting ping-backs that people are hitting it.
    - P-high seems appropriate
    - Current suggestion is to implement diagnostic so tagging as wg-diagnostic.

- How should we expose atomic load/store on targets that don't support full atomics #99668
    - Downgraded to P-medium as all Tier 1 and Tier 2 targets have `+forced-atomics` support in recent LLVM versions (only two Tier 3 targets remain lack this feature). 

- Double free on Linux with stable toolchain #100914
    - Still an issue. P-high makes sense.
    - Tagging as wg-llvm

- Codegen weirdness for sum of count_ones over an array #101060
    - Still an issue on LLVM 16 & 17
    - Tagging as wg-llvm

- extern "C" functions don't generate the same IR definitions as clang on x86, causing problems with cross-language LTO #102174
    - State is unchanged since last visit
    - Validating our ABIs with a tool like abi-cafe would be very helpful in discovering these kinds of issues. 
    - Leaving as-is for now

- Memory sanitizer : false positive regression in nightly-2023-01-18 #107149
    - Closing as expected given the mismatch between msan versions in C and Rust.

- Miscompilation: Equal pointers comparing as unequal #107975
    - Tagging as wg-llvm as this is really just tracking an upstream LLVM bug

- miscompilation with incremental + unpacked debug + macos #108216
    - Seems like it might be fixed?
    - Assigned to lqd to test on their mac
    - If fixed, we'll just close as the test is too non-deterministic to check into our test suite.



[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+-label%3AT-types+-label%3AWG-llvm

[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

