T-compiler Meeting Agenda 2024-04-11

--- tags: weekly, rustc type: docs note_id: apkP_NKkQFyezgpc2HH3xA --- # T-compiler Meeting Agenda 2024-04-11 ## Announcements - Release of Rust stable 1.77.2 ([blog post](https://blog.rust-lang.org/2024/04/09/cve-2024-24576.html)) (fixes the CVE on Windows platforms that is around now: args parsing for Windows scripts) - Reminder: if you see a PR/issue that seems like there might be legal implications due to copyright/IP/etc, please let us know (or at least message @_**davidtwco** 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)) - Types Team: ITE (Impl Trait Everywhere) Triage <time:2024-04-11T22:00:00+01:00> ## MCPs/FCPs - New MCPs (take a look, see if you like them!) - "Partial compilation using MIR-only rlibs" [compiler-team#738](https://github.com/rust-lang/compiler-team/issues/738) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Partial.20compilation.20using.20MIR-only.20rlibs.20compiler-team.23738)) - 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) - "Target families for executable format" [compiler-team#716](https://github.com/rust-lang/compiler-team/issues/716) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Target.20families.20for.20executable.20format.20compiler-team.23716)) (last review activity: 2 months ago) - "Add `--emit=` to emit nothing" [compiler-team#718](https://github.com/rust-lang/compiler-team/issues/718) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20.60--emit.3D.60.20to.20emit.20nothing.20compiler-team.23718)) (last review activity: 2 months ago) - "Promote riscv64gc-unknown-linux-musl to tier 2" [compiler-team#728](https://github.com/rust-lang/compiler-team/issues/728) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Promote.20riscv64gc-unknown-linux-gnu.20to.20ti.E2.80.A6.20compiler-team.23728)) (last review activity: about 34 days ago) - "Skip virtual drop for !needs_drop types" [compiler-team#730](https://github.com/rust-lang/compiler-team/issues/730) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Skip.20virtual.20drop.20for.20.21needs_drop.20types.20compiler-team.23730)) (last review activity: about 6 days ago) - "Add `-Zemit-thin-lto-index=<path>` to enable distributed ThinLTO users" [compiler-team#735](https://github.com/rust-lang/compiler-team/issues/735) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20.60-Zemit-thin-lto-index.3D.3Cpath.3E.60.20to.20ena.E2.80.A6.20compiler-team.23735)) (last review activity: about 6 days ago) - "Only emit forward compatible v0 symbol names with graceful degradation" [compiler-team#737](https://github.com/rust-lang/compiler-team/issues/737) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Only.20emit.20forward.20compatible.20v0.20symbol.20na.E2.80.A6.20compiler-team.23737)) (last review activity: about 6 days ago) - Pending FCP requests (check your boxes!) - merge: [Make casts of pointers to trait objects stricter (rust#120248)](https://github.com/rust-lang/rust/pull/120248#issuecomment-1981506568) - @_**|239881** @_**|116883** @_**|125270** - no pending concerns - Things in FCP (make sure you're good with it) - "allow all command line flags to be passed multiple times, overwriting previous usages" [compiler-team#731](https://github.com/rust-lang/compiler-team/issues/731) - "Tracking Issue for RFC 3013: Checking conditional compilation at compile time" [rust#82450](https://github.com/rust-lang/rust/issues/82450) - "Ignore `-C strip` on MSVC" [rust#115120](https://github.com/rust-lang/rust/pull/115120) - "sess: stabilize `-Zrelro-level` as `-Crelro-level`" [rust#121694](https://github.com/rust-lang/rust/pull/121694) - Accepted MCPs - No new accepted proposals this time. - MCPs blocked on unresolved concerns - merge: [Retire the mailing list and make all decisions on zulip (compiler-team#649)](https://github.com/rust-lang/compiler-team/issues/649#issuecomment-1618781780) - no pending checkboxs - [automatic-sync (by compiler-errors)](https://github.com/rust-lang/compiler-team/issues/649#issuecomment-1618902660) [single-point-of-failure-via-stream-archival (by pnkfelix)](https://github.com/rust-lang/compiler-team/issues/649#issuecomment-1664056989) - merge: [Stabilize `--env-set` option (rust#119926)](https://github.com/rust-lang/rust/pull/119926#issuecomment-1898766442) - @_**|119009** @_**|116083** @_**|124288** @_**|123586** @_**|125250** @_**|119031** @_**|124287** @_**|116118** - [other-rustc-vars (by petrochenkov)](https://github.com/rust-lang/rust/pull/119926#issuecomment-1900703005) - merge: [Add a new `--build-id` flag to rustc (compiler-team#635)](https://github.com/rust-lang/compiler-team/issues/635#issuecomment-1777545767) - @_**|125250** @_**|116107** @_**|125294** @_**|123856** - [other-existing-options (by petrochenkov)](https://github.com/rust-lang/compiler-team/issues/635#issuecomment-1779597156) [option-name (by wesleywiser)](https://github.com/rust-lang/compiler-team/issues/635#issuecomment-1785349936) - "Add hygiene attributes to compile expanded source code" [compiler-team#692](https://github.com/rust-lang/compiler-team/issues/692) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20option.20to.20compile.20expanded.20ASTs.20for.20h.E2.80.A6.20compiler-team.23692)) - concern: [added-complexity-to-frontend](https://github.com/rust-lang/compiler-team/issues/692#issuecomment-1845169318) - Finalized FCPs (disposition merge) - "Pass list of defineable opaque types into canonical queries" [rust#122077](https://github.com/rust-lang/rust/pull/122077) - Other teams finalized FCPs - "privacy: Stabilize lint `unnameable_types`" [rust#120144](https://github.com/rust-lang/rust/pull/120144) - "Pass list of defineable opaque types into canonical queries" [rust#122077](https://github.com/rust-lang/rust/pull/122077) ### WG checkins - @_*T-rust-analyzer* by @**Lukas Wirth** (last [checkin](https://hackmd.io/kumG_EirTtOWJiQcgji7_w#WG-checkins)): > Checkin text ## Backport nominations [T-compiler beta](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Abeta-nominated+-label%3Abeta-accepted+label%3AT-compiler) / [T-compiler stable](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Astable-nominated+-label%3Astable-accepted+label%3AT-compiler) - :beta: [1.78] "fix attribute validation on associated items in traits" [rust#121545](https://github.com/rust-lang/rust/pull/121545) - Merged. Fixes #121537 (ICE on AST lowering) - Should also fix #123287, @_**pnkfelix** is investigating ([comment](https://github.com/rust-lang/rust/pull/121545#issuecomment-2040326320))  - :beta: [1.78] "Only inspect user-written predicates for privacy concerns" [rust#123377](https://github.com/rust-lang/rust/pull/123377) - merged. Fixes #123288, P-high regression in latest crater run  - :beta: [1.78] "Check def id before calling `match_projection_projections`" [rust#123471](https://github.com/rust-lang/rust/pull/123471) - merged. Fixes #123448, compilation started looping forever (comment about [the fix](https://github.com/rust-lang/rust/pull/123471#issue-2226407754))  - :beta: [1.78] "Update to LLVM 18.1.3" [rust#123555](https://github.com/rust-lang/rust/pull/123555) - merged. backports an LLVM patch. Fixes #122805 (p-medium codegen regression)  - :beta: [1.78] "Restore `pred_known_to_hold_modulo_regions`" [rust#123578](https://github.com/rust-lang/rust/pull/123578) - merged. Fixes #123275 (regression from crater run)  - :beta: [1.78] "Properly handle emojis as literal prefix in macros" [rust#123752](https://github.com/rust-lang/rust/pull/123752) - Fixes #123696, old stable-to-stable regression, nice but not a *vital* backport (see [comment](https://github.com/rust-lang/rust/pull/123752#issuecomment-2048446832)) - Not merged, waiting for a crater run  - No stable nominations for `T-compiler` this time. [T-types stable](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Abeta-nominated+-label%3Abeta-accepted+label%3AT-types) / [T-types beta](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Astable-nominated+-label%3Astable-accepted+label%3AT-types) - No beta nominations for `T-types` this time. - No stable nominations for `T-types` this time. ## 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) - [Issues in progress or waiting on other teams](https://hackmd.io/XYr1BrOWSiqCrl8RCWXRaQ) ## Issues of Note ### Short Summary - [2 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) - [64 T-compiler P-high issues](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high) - [34 of those are unassigned](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high+no%3Aassignee) - [1 P-critical, 5 P-high, 4 P-medium, 1 P-low regression-from-stable-to-beta](https://github.com/rust-lang/rust/labels/regression-from-stable-to-beta) - [0 P-critical, 1 P-high, 5 P-medium, 2 P-low regression-from-stable-to-nightly](https://github.com/rust-lang/rust/labels/regression-from-stable-to-nightly) - [1 P-critical, 35 P-high, 100 P-medium, 17 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) - "regression: unwrap on None in ast lowering" [rust#123287](https://github.com/rust-lang/rust/issues/123287) - *could* be fixed by #121545 (see [comment](https://github.com/rust-lang/rust/pull/121545#issuecomment-2040326320), @**pnkfelix** thanks!) [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` 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) - "regression: ICE failed to get output type of async function" [rust#123273](https://github.com/rust-lang/rust/issues/123273) - under @**Michael Goulet (compiler-errors)** eyes - "regression: unexpected unsized tail ICE" [rust#123275](https://github.com/rust-lang/rust/issues/123275) - Fixed by #123578 - "regression: trait bound is not satisfied" [rust#123279](https://github.com/rust-lang/rust/issues/123279) - will be closed by #123302 (merged and beta accepted) - "regression: f16 + f128 is unstable" [rust#123282](https://github.com/rust-lang/rust/issues/123282) - Will be fixed by #123466 (merged straight into beta with a few other patches) [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+) - "nightly-2024-04-05 regression: error[E0275]: overflow evaluating the requirement" [rust#123573](https://github.com/rust-lang/rust/issues/123573) - reported by a project using Bevy and by the Diesel maintainer - seems the new solver could help here. See [comment](https://github.com/rust-lang/rust/issues/123573#issuecomment-2041348320) and PR #123594 (in FCP) ## Performance logs > [triage logs for 2024-04-11](https://github.com/rust-lang/rustc-perf/blob/master/triage/2024-04-09.md) A quiet week; all the outright regressions were already triaged (the one biggish one was #122077, which is justified as an important bug fix). There was a very nice set of improvements from PR #122070, which cleverly avoids a lot of unnecessary allocator calls when building an incremental dep graph by reusing the old edges from the previous graph. Triage done by **@pnkfelix**. Revision range: [3d5528c2..86b603cd](https://perf.rust-lang.org/?start=3d5528c287860b918e178a34f04ff903325571b3&end=86b603cd792b3f6172ba4f676d7b586c1af7630a&absolute=false&stat=instructions%3Au) **Summary**: | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 2.0% | [0.4%, 5.0%] | 83 | | Regressions (secondary) | 2.1% | [0.5%, 4.8%] | 79 | | Improvements (primary) | -1.5% | [-2.9%, -0.3%] | 121 | | Improvements (secondary) | -1.4% | [-3.5%, -0.3%] | 67 | | All (primary) | -0.1% | [-2.9%, 5.0%] | 204 | 3 Regressions, 3 Improvements, 7 Mixed; 1 of them in rollups 78 artifact comparisons made in total #### Regressions instantiate higher ranked goals outside of candidate selection [#119820](https://github.com/rust-lang/rust/pull/119820) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0accf4ec4c07d23aa86f6a97aeb8797941abc30e&end=43f4f2a3b1a3d3fb3dbbbe4fde33fb97c780ee98&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:----:|:------------:|:-----:| | Regressions (primary) | 0.6% | [0.3%, 0.8%] | 8 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | - | - | 0 | | All (primary) | 0.6% | [0.3%, 0.8%] | 8 | * already triaged by Jakub as an expected small performance regresison Pass list of defineable opaque types into canonical queries [#122077](https://github.com/rust-lang/rust/pull/122077) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=ab5bda1aa70f707014e2e691e43bc37a8819252a&end=b234e449443a49ab19ef6b712bf56cc65927d98f&stat=instructions:u) | (instructions:u) | mean | range | count | |:-----------------------:|:----:|:------------:|:-----:| | Regressions (primary) | 1.9% | [0.2%, 5.4%] | 101 | | Regressions (secondary) | 2.3% | [0.3%, 4.7%] | 77 | | Improvements (secondary) | - | - | 0 | | All (primary) | 1.8% | [-0.6%, 5.4%] | 102 | * already triaged by oli, as an expected performance regression that is [justified](https://github.com/rust-lang/rust/pull/122077#issuecomment-1995694305) as an important bugfix Replace some `CrateStore` trait methods with hooks. [#123099](https://github.com/rust-lang/rust/pull/123099) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=59c808fcd9eeb3c5528209d1cef3aaa5521edbd6&end=bd12986fd6659a3091cff7694b8225374f4a26fe&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:----:|:------------:|:-----:| | Regressions (primary) | 0.3% | [0.2%, 0.4%] | 14 | | Regressions (secondary) | 0.3% | [0.3%, 0.4%] | 2 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | - | - | 0 | | All (primary) | 0.3% | [0.2%, 0.4%] | 14 | * already triaged by oli, categorized as noise. #### Improvements hir: Drop owner's own item-local id (zero) from parenting tables [#123415](https://github.com/rust-lang/rust/pull/123415) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=703dc9ce64d9b31a239a7280d9b5f9ddd85ffed6&end=98efd808e1b77cd70a097620aad6250727167a28&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.3% | [-0.4%, -0.2%] | 3 | | Improvements (secondary) | -0.4% | [-1.3%, -0.3%] | 13 | | All (primary) | -0.3% | [-0.4%, -0.2%] | 3 | [perf] cache type info for ParamEnv [#123058](https://github.com/rust-lang/rust/pull/123058) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=6f837503aa120ca69c2985b6c9a474c00674cef1&end=087ae978a13013800c8a484cf17c8951ab0b6b0c&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.9% | [-4.9%, -0.2%] | 47 | | Improvements (secondary) | - | - | 0 | | All (primary) | -0.9% | [-4.9%, -0.2%] | 47 | Remove debuginfo from rustc-demangle too [#123608](https://github.com/rust-lang/rust/pull/123608) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0e5f5207881066973486e6a480fa46cfa22947e9&end=75fd074338801fba74a8cf7f8c48c5c5be362d08&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | 0.6% | [0.4%, 0.9%] | 4 | | Improvements (primary) | -1.6% | [-2.7%, -0.3%] | 7 | | Improvements (secondary) | -1.3% | [-2.4%, -0.3%] | 24 | | All (primary) | -1.6% | [-2.7%, -0.3%] | 7 | #### Mixed Add `Ord::cmp` for primitives as a `BinOp` in MIR [#118310](https://github.com/rust-lang/rust/pull/118310) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=029cb1b13b6388b95e64e8996ec8b41a9f3cf16e&end=a77322c16f188402fa22a5e87100acce42433cbc&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.4% | [0.2%, 0.7%] | 3 | | Regressions (secondary) | 0.3% | [0.2%, 0.4%] | 2 | | Improvements (primary) | -0.6% | [-0.6%, -0.6%] | 1 | | Improvements (secondary) | -3.1% | [-3.1%, -3.1%] | 1 | | All (primary) | 0.2% | [-0.6%, 0.7%] | 4 | * The impact here is somewhat limited, and the graph indicates that the 0.69% instruction-count regression for image-0.24.1 was subsequently recovered. Encode dep graph edges directly from the previous graph when promoting [#122070](https://github.com/rust-lang/rust/pull/122070) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=d009f60b55fe4527e7ddf122bc4520f351d7b9d4&end=4563f70c3b599411836e285591479f4a3d364708&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | 0.4% | [0.4%, 0.4%] | 1 | | Improvements (primary) | -1.6% | [-3.1%, -0.2%] | 113 | | Improvements (secondary) | -1.5% | [-3.6%, -0.3%] | 37 | | All (primary) | -1.6% | [-3.1%, -0.2%] | 113 | * already marked as triaged by Jakub Implement T-types suggested logic for perfect non-local impl detection [#122747](https://github.com/rust-lang/rust/pull/122747) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=ea40fa210b87a322d2259852c149ffa212a3a0da&end=9d79cd5f79e75bd0d2083260271307ce9acd9081&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 2.3% | [0.6%, 4.4%] | 12 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.3% | [-0.4%, -0.2%] | 9 | | Improvements (secondary) | - | - | 0 | | All (primary) | 1.2% | [-0.4%, 4.4%] | 21 | * already marked as triaged by Urgau, with the comment "The perf regressions in diesel are due to the lint being triggered and producing nearly 300 warnings (with 155 actually shown)" * (This reminds me of rustc-perf#1819) Remove sharding for VecCache [#123556](https://github.com/rust-lang/rust/pull/123556) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=087ae978a13013800c8a484cf17c8951ab0b6b0c&end=af2525317be950fdae635bcbb46b3e755d14ab49&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.4% | [0.4%, 0.4%] | 1 | | Regressions (secondary) | 0.5% | [0.2%, 1.0%] | 5 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | -0.9% | [-1.1%, -0.7%] | 4 | | All (primary) | 0.4% | [0.4%, 0.4%] | 1 | * already marked as triaged by simulacrum, presumably because this is likely noise since it is "just" removing the sharded type whose feature was not in use. Use unchecked_sub in str indexing [#123561](https://github.com/rust-lang/rust/pull/123561) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=fc1a4c5cc9308c4b5980c64a73fd344a59c10601&end=4e431fad67b46c480f1833119cd368fa33df95f7&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.9% | [0.9%, 0.9%] | 1 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | -0.5% | [-0.9%, -0.4%] | 7 | | All (primary) | 0.9% | [0.9%, 0.9%] | 1 | * this is an improvement to the code for `str::get_unchecked` when overflow checks are enabled; its calling a compiler-intrinsic directly now. * it really doesn't make any sense that it caused any regression at all. (Perhaps this change is causing a change to inlining decisions, at least for cargo?) * marking as triaged. Rollup of 9 pull requests [#123645](https://github.com/rust-lang/rust/pull/123645) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=211518e5fb1336de6a4aab45dc1c05f5d83ce856&end=ab5bda1aa70f707014e2e691e43bc37a8819252a&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.6% | [0.6%, 0.6%] | 1 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.3% | [-0.4%, -0.3%] | 2 | | Improvements (secondary) | -1.8% | [-1.8%, -1.8%] | 1 | | All (primary) | -0.0% | [-0.4%, 0.6%] | 3 | * Looks like a temporary spike. Marking as triaged. Only collect mono items from reachable blocks [#123272](https://github.com/rust-lang/rust/pull/123272) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=86b603cd792b3f6172ba4f676d7b586c1af7630a&end=bb78dba64ca4158ef2f3488d0d41a82c75a504f2&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.4% | [0.2%, 1.5%] | 8 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.8% | [-1.5%, -0.3%] | 6 | | Improvements (secondary) | - | - | 0 | | All (primary) | -0.1% | [-1.5%, 1.5%] | 14 | * fixed an important bug. * from the comment history, it looks like the minor restricted regressions were anticipated. * marking as triaged. ## Nominated Issues [T-compiler](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AI-compiler-nominated) - "Fallout from expansion of redundant import checking" [rust#121708](https://github.com/rust-lang/rust/issues/121708) - Fallout from #117772, added some linting improving `use` import redundancy. - Nominated for T-lang and T-compiler by @**Josh Triplett** [see comment](https://github.com/rust-lang/rust/issues/121708#issuecomment-2032578032) - change is already on beta, but it has *some* [impact](https://github.com/rust-lang/rust/issues/121708#issuecomment-2029760942), so in the meanwhile it will reverted ([comment](https://github.com/rust-lang/rust/issues/121708#issuecomment-2048105393)) - "Consider using `llvm-strip`" [rust#123151](https://github.com/rust-lang/rust/issues/123151) - proposal advanced by @_**Jubilee**, there's also a [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/241545-t-release/topic/llvm-tools.20stabilization/near/418694252) > on various systems, we are encountering reports of people having inadequately-built strip binaries in their PATH that cannot support all Rust compiler use-cases (...) `llvm-strip` gets everything right, as far as we are concerned - "regression: compiler had non-unwinding abort" [rust#123286](https://github.com/rust-lang/rust/issues/123286) - this is a beta crater run regression. Actually we fixed a UB ([comment](https://github.com/rust-lang/rust/issues/123286#issuecomment-2029536170)): "People were executing UB, we now prevent that and try to tell them about it" - @**Ben Kimock (Saethlin)** suggests a possible quick fix for a beta backport ([comment](https://github.com/rust-lang/rust/issues/123286#issuecomment-2030344815)) [RFC](https://github.com/rust-lang/rfcs/issues?q=is%3Aopen+label%3AI-compiler-nominated) - No I-compiler-nominated RFCs this time. ### 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) - "Issue 83060 fix" [rust#119798](https://github.com/rust-lang/rust/pull/119798) (last review activity: 3 months ago) - cc @**Wesley Wiser** - "Small improvements to internal documentation" [rust#120388](https://github.com/rust-lang/rust/pull/120388) - cc: @**Esteban Küber** - "Suggest a borrow when using dbg" [rust#120990](https://github.com/rust-lang/rust/pull/120990) (last review activity: about 58 days ago) - cc: @**Esteban Küber** - "Always emit `native-static-libs` note, even if it is empty" [rust#121216](https://github.com/rust-lang/rust/pull/121216) (last review activity: about 54 days ago) - cc @**Wesley Wiser** CI fails and author asked for input. Can you help there? thanks ## Next week's WG checkins - Impl Trait initiative by @**oli** - @_*WG-llvm* by @**nagisa** and @**Nikita Popov** Next meetings' agenda draft: [hackmd link](https://hackmd.io/uKNODHUfQ2mUIjQtDiGwdg)

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