Use PGO for rustdoc - #159091

Kobzol · 2026-07-10T14:46:46Z

This PR extends the recently added support for configuring PGO options per component in bootstrap to support rustdoc and enables PGO training on Doc benchmarks.

We build PGO-instrumented rustc and rustdoc together.

I tested two variants:

Run all rustc benchmarks also on Doc rustc-perf profiles, and then use the same merged PGO profile to optimize both rustc and rustdoc
- Use PGO for rustdoc #159091 (comment)
Run rustc benchmarks separately, and generate the rustc PGO profile from that, same as before. Then run only Doc benchmarks, and generate a rustdoc PGO profile from that, and use that to optimize rustdoc (note that here we run the Doc benchmarks using a PGO instrumented rustc too, so the profiles will include PGO data from librustc_driver.so).
- Use PGO for rustdoc #159091 (comment)

I think that the second reason is slightly better, and produces better results (and less rustc regressions).

Gathering the rustdoc PGO profiles takes barely over a minute, I don't think that this should have a large effect on the duration of the dist-x86_64-linux job.

try-job: dist-x86_64-msvc
try-job: dist-x86_64-linux

Kobzol · 2026-07-10T14:49:26Z

@bors try jobs=dist-x86_64-linux @rust-timer queue

Use PGO for rustdoc try-job: dist-x86_64-linux

rust-bors · 2026-07-10T18:17:00Z

☀️ Try build successful (CI)
Build commit: 633dfd7 (633dfd7c537f088ac1df67ea22f1d10215599cd7)
Base parent: 31e4b84 (31e4b8481fec5ae856d786ff3b75a5bccaf33725)

rust-timer · 2026-07-10T19:23:03Z

Finished benchmarking commit (633dfd7): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.2%, 0.5%]	12
Regressions ❌ (secondary)	0.7%	[0.1%, 4.7%]	20
Improvements ✅ (primary)	-3.0%	[-5.5%, -0.2%]	26
Improvements ✅ (secondary)	-1.9%	[-7.1%, -0.1%]	59
All ❌✅ (primary)	-2.0%	[-5.5%, 0.5%]	38

Max RSS (memory usage)

Results (primary -2.5%, secondary -2.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.7%, 0.7%]	1
Regressions ❌ (secondary)	2.7%	[1.5%, 3.9%]	2
Improvements ✅ (primary)	-2.7%	[-4.1%, -1.3%]	20
Improvements ✅ (secondary)	-2.8%	[-6.4%, -0.9%]	25
All ❌✅ (primary)	-2.5%	[-4.1%, 0.7%]	21

Cycles

Results (primary -3.2%, secondary -2.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.7%	[2.3%, 3.1%]	2
Regressions ❌ (secondary)	4.1%	[1.5%, 7.6%]	7
Improvements ✅ (primary)	-3.9%	[-6.3%, -2.4%]	16
Improvements ✅ (secondary)	-3.9%	[-6.5%, -1.4%]	28
All ❌✅ (primary)	-3.2%	[-6.3%, 3.1%]	18

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 488.684s -> 492.189s (0.72%)
Artifact size: 389.90 MiB -> 393.63 MiB (0.96%)

Kobzol · 2026-07-11T08:55:16Z

@bors try @rust-timer queue

Use PGO for rustdoc

rust-bors · 2026-07-11T11:12:48Z

☀️ Try build successful (CI)
Build commit: 2901b24 (2901b2439ed3b863a94c1eca3db1b447dd57df29)
Base parent: ad49852 (ad49852b6f3dd9c1c73fe909d8843bb7e464b387)

rust-timer · 2026-07-11T11:53:33Z

Finished benchmarking commit (2901b24): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.4%, 0.7%]	3
Regressions ❌ (secondary)	0.8%	[0.2%, 4.5%]	13
Improvements ✅ (primary)	-4.1%	[-6.3%, -1.6%]	20
Improvements ✅ (secondary)	-4.9%	[-8.2%, -0.7%]	24
All ❌✅ (primary)	-3.5%	[-6.3%, 0.7%]	23

Max RSS (memory usage)

Results (primary -3.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.1%	[-3.9%, -2.3%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.1%	[-3.9%, -2.3%]	2

Cycles

Results (primary -3.8%, secondary -4.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	5.8%	[5.8%, 5.8%]	1
Improvements ✅ (primary)	-3.8%	[-4.9%, -1.9%]	19
Improvements ✅ (secondary)	-4.4%	[-5.8%, -2.3%]	24
All ❌✅ (primary)	-3.8%	[-4.9%, -1.9%]	19

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 488.317s -> 488.723s (0.08%)
Artifact size: 389.82 MiB -> 391.43 MiB (0.41%)

Kobzol · 2026-07-11T13:06:21Z

@bors try jobs=dist-x86_64-linux

Testing full CI duration.

Use PGO for rustdoc try-job: dist-x86_64-linux

rustbot · 2026-07-11T13:14:15Z

This PR modifies bootstrap.example.toml.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

This PR modifies src/bootstrap/src/core/config.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

rustbot · 2026-07-11T13:14:17Z

r? @Mark-Simulacrum

rustbot has assigned @Mark-Simulacrum.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

Fallback group: @Mark-Simulacrum, @jieyouxu
@Mark-Simulacrum, @jieyouxu expanded to Mark-Simulacrum, jieyouxu
Random selection from Mark-Simulacrum, jieyouxu

Use PGO for rustdoc try-job: dist-x86_64-msvc try-job: dist-x86_64-linux

rust-bors · 2026-07-15T13:55:37Z

☀️ Try build successful (CI)
Build commit: c5f8f1c (c5f8f1c8700e7d2d5a717bc5b308c33ad097f594)
Base parent: 47101ad (47101adcea71daee3c2879218f5b883bcdf180aa)

Kobzol · 2026-07-15T15:00:20Z

@rust-timer build c5f8f1c

Kobzol · 2026-07-15T15:00:42Z

@rustbot ready

rust-timer · 2026-07-15T15:41:00Z

Finished benchmarking commit (c5f8f1c): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.3%	[0.2%, 4.5%]	2
Improvements ✅ (primary)	-4.1%	[-6.3%, -1.6%]	20
Improvements ✅ (secondary)	-5.1%	[-8.1%, -2.0%]	23
All ❌✅ (primary)	-4.1%	[-6.3%, -1.6%]	20

Max RSS (memory usage)

Results (primary -3.7%, secondary 6.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	6.3%	[6.3%, 6.3%]	1
Improvements ✅ (primary)	-3.7%	[-3.7%, -3.7%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.7%	[-3.7%, -3.7%]	1

Cycles

Results (primary -3.9%, secondary -4.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.9%	[-5.8%, -2.6%]	18
Improvements ✅ (secondary)	-4.2%	[-5.5%, -2.7%]	23
All ❌✅ (primary)	-3.9%	[-5.8%, -2.6%]	18

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 491.257s -> 488.522s (-0.56%)
Artifact size: 389.43 MiB -> 389.42 MiB (-0.00%)

Kobzol · 2026-07-15T19:29:52Z

Good. I fixed the Windows CI failures, both in opt-dist and rustc-perf.

GuillaumeGomez · 2026-07-16T10:13:28Z

Nice!

Kobzol · 2026-07-17T15:46:59Z

@bors r=Mark-Simulacrum

rust-bors · 2026-07-17T15:47:02Z

📌 Commit f14f0c1 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

rust-bors · 2026-07-17T23:15:37Z

☀️ Test successful - CI
Approved by: Mark-Simulacrum
Duration: 3h 18m 1s
Pushing b6839f4 to main...

github-actions · 2026-07-17T23:19:27Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 421875f (parent) -> b6839f4 (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard b6839f4d0e2bd63b960bbff8619c6fdea27d81e5 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

dist-armhf-linux: 1h 1m -> 1h 33m (+52.9%)
x86_64-gnu-gcc-core-tests: 14m 14s -> 8m (-43.7%)
dist-powerpc64-linux-gnu: 1h 5m -> 1h 32m (+41.1%)
dist-apple-various: 1h 23m -> 1h 56m (+38.7%)
dist-loongarch64-musl: 1h 17m -> 1h 45m (+37.5%)
x86_64-msvc-ext3: 1h 53m -> 1h 14m (-34.0%)
dist-x86_64-solaris: 1h 37m -> 1h 7m (-30.3%)
x86_64-msvc-ext2: 1h 47m -> 1h 21m (-24.0%)
x86_64-gnu-llvm-21-3: 1h 33m -> 1h 54m (+22.7%)
dist-x86_64-mingw: 2h 1m -> 2h 28m (+21.9%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2026-07-17T23:57:21Z

Finished benchmarking commit (b6839f4): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

If the regression was expected or you think it can be justified,
please write a comment with sufficient written justification, and add
@rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
If you think that you know of a way to resolve the regression, try to create
a new PR with a fix for the regression.
If you do not understand the regression or you think that it is just noise,
you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	4.5%	[4.5%, 4.5%]	1
Improvements ✅ (primary)	-4.1%	[-6.3%, -1.6%]	20
Improvements ✅ (secondary)	-5.1%	[-8.1%, -2.0%]	23
All ❌✅ (primary)	-4.1%	[-6.3%, -1.6%]	20

Max RSS (memory usage)

Results (primary -5.8%, secondary -3.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-5.8%	[-5.8%, -5.8%]	1
Improvements ✅ (secondary)	-3.9%	[-4.9%, -2.9%]	2
All ❌✅ (primary)	-5.8%	[-5.8%, -5.8%]	1

Cycles

Results (primary -3.0%, secondary -3.8%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.2%, 2.5%]	2
Regressions ❌ (secondary)	2.4%	[2.4%, 2.4%]	1
Improvements ✅ (primary)	-3.6%	[-5.5%, -2.0%]	18
Improvements ✅ (secondary)	-4.1%	[-5.7%, -2.2%]	22
All ❌✅ (primary)	-3.0%	[-5.5%, 2.5%]	20

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 491.802s -> 490.163s (-0.33%)
Artifact size: 389.50 MiB -> 390.10 MiB (0.15%)

Use PGO for rustdoc This PR extends the recently added support for configuring PGO options per component in bootstrap to support `rustdoc` and enables PGO training on `Doc` benchmarks. We build PGO-instrumented rustc and rustdoc together. I tested two variants: - Run all rustc benchmarks *also* on `Doc` rustc-perf profiles, and then use the same merged PGO profile to optimize both rustc and rustdoc - rust-lang/rust#159091 (comment) - Run rustc benchmarks separately, and generate the rustc PGO profile from that, same as before. Then run *only* `Doc` benchmarks, and generate a rustdoc PGO profile from that, and use that to optimize rustdoc (note that here we run the `Doc` benchmarks using a PGO instrumented rustc too, so the profiles will include PGO data from librustc_driver.so). - rust-lang/rust#159091 (comment) I think that the second reason is slightly better, and produces better results (and less rustc regressions). Gathering the rustdoc PGO profiles takes barely over a minute, I don't think that this should have a large effect on the duration of the `dist-x86_64-linux` job. try-job: dist-x86_64-msvc try-job: dist-x86_64-linux

Kobzol · 2026-07-21T07:35:42Z

Many wins on doc benchmarks, expectedly, one regression on a secondary benchmark.

@rustbot label: +perf-regression-triaged

Pkgsrc changes: * Adapt to changes in vendored crate versions. * Version & checksum changes. Upstream changes: Version 1.99.0 (2026-10-01) ========================== Language -------- - [Add allow-by-default `raw_borrows_via_references` lint that checks for references that decay immediately into raw borrows](rust-lang/rust#138230) - [Extend `unconditional_panic` lint to function calls that panic when the chunks/windows size is zero] (rust-lang/rust#153563) - [Stabilize C-variadic function definitions] (rust-lang/rust#155697) - [Stabilize the ability to use `#[unsafe(naked)]` functions to define C-variadic functions (`#![feature(c_variadic_naked_functions)]`).] (rust-lang/rust#159746) - [Trait methods are now resolved on an adjusted never type (producing a FCW)] (rust-lang/rust#156047) - [Coerce from inference variables to trait objects if the inference variable is related via subtyping to a type that is known to be `Sized`] (rust-lang/rust#157820) - [Stabilize `#[my_macro] mod foo;`] (rust-lang/rust#157857). This allows outlined modules (`mod foo;`) anywhere in the body of a custom attribute or derive macro. - [Fix the `overflowing_literals` lint with repeated negation] (rust-lang/rust#158302). For instance, it will now no longer lint on `--128_i8`, which is already detected by the `arithmetic_overflow` lint. - [Add POSIX symbols to the `invalid_runtime_symbol_definitions` and `suspicious_runtime_symbol_definitions` lints] (rust-lang/rust#158522) - [Lint unused `#[path]` attributes on inline modules] (rust-lang/rust#158835) - [Enable `unreachable_cfg_select_predicates` lint as part of `unused` lint group] (rust-lang/rust#159179) - [Stabilize passing 128-bit integers via vector registers with `asm!` on x86] (rust-lang/rust#159525) - [Explicitly document that some allocations are allowed to grow in-place (but none are allowed to shrink)] (rust-lang/rust#159729) - We now [guarantee] (rust-lang/rust#159730) that the contents of an `UnsafeCell` can be accessed without going through `get` - [The `invalid_reference_casting` lint was adjusted accordingly] (rust-lang/rust#159960) - [Account for globally enabled target features in `global_asm!`] (rust-lang/rust#160594) - [Warn if an invalid `doc` attribute is used on a macro invocation] (rust-lang/rust#161003) Compiler -------- - [Convert `-Ctarget-cpu` into a target-modifier for AVR, AMDGCN and NVPTX] (rust-lang/rust#150732) - [Enable `static_position_independent_executables` on all gnu and musl targets] (rust-lang/rust#158510) - When providing a suggestion about a missing method, rustc now prefers an exactly matching name from a [doc alias attribute] (https://doc.rust-lang.org/rustdoc/advanced-features.html#add-aliases-for-an-item-in-documentation-search) over a similarity search from other method names. If your new users sometimes expect a method under a different name, adding a doc alias will now help them find it via rustc suggestions, in addition to helping them find it via rustdoc search: [When suggesting method names, prefer *exact* doc aliases over similar names](rust-lang/rust#160369) Platform Support ---------------- - [Promote `riscv64-unknown-linux-musl` to Tier 2 with host tools] (rust-lang/rust#158766) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. [platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html Libraries --------- - Iteration on `RangeInclusive` (`a..=b` ranges) is now [optimized better in some circumstances] (rust-lang/rust#155114). As a side effect of this, the behavior of `RangeInclusive` values that has already been exhausted (as an iterator) has changed. For example, the return values of `start()` and `end()` on such ranges may return different values, and using such ranges as slice indexes may have different behavior. These behaviors were not guaranteed to be stable, so these changes are considered to not be breaking changes. - [Relax `transmute_copy` to accept `?Sized` types] (rust-lang/rust#155989) - [Update `transmute_copy` to use a non-unwinding panic] (rust-lang/rust#155989) - [Don't escape U+FF9E and U+FF9F in `escape_debug_ext`] (rust-lang/rust#158057) - [Re-export `core::fmt::NumBuffer` in `alloc` (and `std`)] (rust-lang/rust#161430) Stabilized APIs --------------- - [`IntoIterator` for `Box<[T; N]>`] (https://doc.rust-lang.org/stable/std/iter/trait.IntoIterator.html#impl-IntoIterator-for-Box%3C%5BT;+N%5D,+A%3E) - [`IntoIterator` for `&Box<[T; N]>`] (https://doc.rust-lang.org/stable/std/iter/trait.IntoIterator.html#impl-IntoIterator-for-%26Box%3C%5BT;+N%5D,+A%3E) - [`IntoIterator` for `&mut Box<[T; N]>`] (https://doc.rust-lang.org/stable/std/iter/trait.IntoIterator.html#impl-IntoIterator-for-%26mut+Box%3C%5BT;+N%5D,+A%3E) - [`VecDeque::retain_back`] (https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.retain_back) - [`core::ffi::VaList`] (https://doc.rust-lang.org/stable/core/ffi/struct.VaList.html) - [`Box::into_non_null`] (https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.into_non_null) - [`Box::from_non_null`] (https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.from_non_null) - [`Vec::into_parts`] (https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.into_parts) - [`Vec::from_parts`] (https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.from_parts) - [`core::mem::size_of_val_raw`] (https://doc.rust-lang.org/stable/core/mem/fn.size_of_val_raw.html) - [`core::mem::align_of_val_raw`] (https://doc.rust-lang.org/stable/core/mem/fn.align_of_val_raw.html) - [`core::alloc::Layout::for_value_raw`] (https://doc.rust-lang.org/stable/core/alloc/struct.Layout.html#method.for_value_raw) - [`String::from_utf8_lossy_owned`] (https://doc.rust-lang.org/stable/std/string/struct.String.html#method.from_utf8_lossy_owned) - [`string::FromUtf8Error::into_utf8_lossy`] (https://doc.rust-lang.org/stable/std/string/struct.FromUtf8Error.html#method.into_utf8_lossy) - [`FusedIterator for StepBy<I>`] (https://doc.rust-lang.org/stable/std/iter/struct.StepBy.html#impl-FusedIterator-for-StepBy%3CI%3E) - [`std::fs::set_times`] (https://doc.rust-lang.org/stable/std/fs/fn.set_times.html) - [`std::fs::set_times_nofollow`] (https://doc.rust-lang.org/stable/std/fs/fn.set_times_nofollow.html) Cargo ----- - Add a new built-in profile `debug`. This is a preparation for transitioning the `dev` profile away from debugging to give a saner default for faster development iterations. Currently there is no difference between `dev` and `debug` profiles. [docs] (https://doc.rust-lang.org/nightly/cargo/reference/profiles.html#debug-1) [#17214] (rust-lang/cargo#17214) - Workspace members on edition 2024 or later can now override an inherited workspace dependency's `default-features` field. For example, `serde = { workspace = true, default-features = false }` now turns off default features even when the workspace definition enables them. On earlier editions, `default-features = false` is ignored with a warning. ([RFC 3945] (rust-lang/rfcs#3945)) [#17126](rust-lang/cargo#17126) - Incremental compilation is now disabled by default when running in CI. CI is detected via the CI environment variable. [#17220] (rust-lang/cargo#17220) See also the [full Cargo changelog] (https://doc.rust-lang.org/nightly/cargo/CHANGELOG.html#cargo-199-2026-10-01) Rustdoc ----- - [Add new `unused_footnote_definition` rustdoc lint] (rust-lang/rust#137858) - Smarter filtering of trait impls yields performance improvements of 20% on average and up to 40% on some real-world crates. ([1] (rust-lang/rust#159623), [2](rust-lang/rust#159721), [3](rust-lang/rust#159779), [4](rust-lang/rust#159854), [5](rust-lang/rust#159091)) Compatibility Notes ------------------- - [Fully deprecate the legacy integral modules] (rust-lang/rust#146882). For example, `std::i32::MAX` should be accessed via `i32::MAX` instead. - [Upgrade `no_mangle_generic_items` into hard error] (rust-lang/rust#154585) - [The `Pin::new_unchecked` has had its safety invariants changed slightly] (rust-lang/rust#156935) - [Do not promote references to extern statics] (rust-lang/rust#157641) - [Ensure that the inferred types of `let` patterns typecheck] (rust-lang/rust#157841) - [hermit/fs: Return `unsupported()` instead of `from_raw_os_error(22)`] (rust-lang/rust#158247) - [Fixed a bug where `#[repr(simd)]` was accidentally allowed on macro invocations on stable Rust] (rust-lang/rust#158523) - [Abort const-eval when there are generics in the type of the value being produced] (rust-lang/rust#159504) - [Attributes not applying to anything are now an error in code blocks in doc comments] (rust-lang/rust#159849) - [`Box::leak`: tell people to avoid unleaking] (rust-lang/rust#160323) - [PowerPC inline ASM: Fix scalar floats being in the wrong vector lane on little endian] (rust-lang/rust#160441) - [Do not take `doc(cfg())` into account when filtering doctests] (rust-lang/rust#159014) - [Infer anonymous lifetimes in the types of associated consts as `'static`] (rust-lang/rust#156508) - Macros that expand to a semicolon now produce a warning lint (`semicolon_in_expressions_from_non_local_macros`) even when the macro comes from another crate. Previously, such warnings only appeared for macros from the same crate, to avoid showing warnings that can't be fixed locally; however, this masked problems, as integration tests from the crate providing the macro get compiled as a separate crate, so tests often wouldn't reveal this issue. If you encounter a lint like this, please make sure to report it to the crate providing the macro so they can fix it; don't just silence it in your own crate. - [`semicolon_in_expressions_from_macros`: Lint on non-local macros too] (rust-lang/rust#159222) - [Split non-local `semicolon_in_expressions_from_macros` into a separate lint] (rust-lang/rust#159700) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Update to LLVM 23] (rust-lang/rust#158734)

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-bootstrap Relevant to the bootstrap subteam: Rust's build system (x.py and src/bootstrap) labels Jul 10, 2026