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