Rollup of 5 pull requests #149818

matthiaskrgr · 2025-12-09T16:36:51Z

Successful merges:

Enable outline-atomics by default on more AArch64 platforms #144938 (Enable outline-atomics by default on more AArch64 platforms)
Handle macro invocation in attribute during parse #146579 (Handle macro invocation in attribute during parse)
unstable proc_macro tracked::* rename/restructure #149400 (unstable proc_macro tracked::* rename/restructure)
attempt to fix unreachable code regression #149664 (attempt to fix unreachable code regression )
Mirror ubuntu:24.04 on ghcr #149806 (Mirror ubuntu:24.04 on ghcr)

Failed merges:

Cleanup in the attribute parsers #149789 (Cleanup in the attribute parsers)

r? @ghost
@rustbot modify labels: rollup

… AsRef<str>

Build outline atomic symbols on all targets that have `outline-atomics` enabled, rather than only on Linux. Since this is no longer OS-specific, also rename the module.

Change the gating and link sections to enable this for any platforms that enable `outline-atomics`, rather than only Linux. Additionally, no longer run this if LSE is available, since in this case the outline versions will never be called.

Windows has a similar flag `/forceInterlockedFunctions`, which uses names such as `_InterlockedAdd64_rel`.

Per LLVM commit c5e7e64 ("[AArch64][Clang][Linux] Enable out-of-line atomics by default.") [1], Clang enables these on Android. Thus, do the same in Rust. [1]: llvm/llvm-project@c5e7e649d537067de

Clang has done this by default since LLVM commit 1a963d3 ("[Driver] Make -moutline-atomics default for aarch64-fuchsia targets"), [1], so do the same here. [1]: llvm/llvm-project@1a963d3

Clang has recently started doing this, as of LLVM commit 5d774ec8d183 ("[Driver] Enable outline atomics for OpenBSD/aarch64") [1]. Thus, do the same here. [1]: llvm/llvm-project@5d774ec

``` error: expected a literal (`1u8`, `1.0f32`, `"string"`, etc.) here, found macro `concat` --> $DIR/macro-in-attribute.rs:4:21 | LL | #[deprecated(note = concat!("a", "b"))] | ^^^^^^^^^^^^^^^^^ macros are not allowed here ```

…avidtwco Enable `outline-atomics` by default on more AArch64 platforms The baseline Armv8.0 ISA doesn't have atomics instructions, but in practice most hardware is at least Armv8.1-A (2014), which includes single-instruction atomics as part of the LSE feature. As a performance optimization for these cases, GCC and LLVM have the `-moutline-atomics` flag to turn atomic operations into calls to symbols like `__aarch64_cas1_acq`. These can do runtime feature detection and use the LSE instructions if available, falling back to more portable load-exclusive/store-exclusive loops. Since the recent 3b50253 ("compiler-builtins: plumb LSE support for aarch64 on linux") our builtins support this LSE optimization, and since 6936bb9 ("Dynamically enable LSE for aarch64 rust provided intrinsics"), std will set the flag as part of its startup code. The first commit in this PR configures this to work on all platforms built with `outline-atomics`, not just Linux. Thus, enable `outline-atomics` by default on Android, OpenBSD, Windows, and Fuchsia platforms that don't have LSE in the baseline. The feature is already enabled on Linux. Platform-specific details are included in each commit message. The current implementation can still be accessed by setting `-Ctarget-feature=-outline-atomics`. Setting `-Ctarget-feature=+lse` or a relevant CPU will use the single-instruction atomics without the call overhead. https://rust.godbolt.org/z/dsdrzszoe Link: https://learn.arm.com/learning-paths/servers-and-cloud-computing/lse/intro/ Original Clang outline-atomics benchmarks: https://reviews.llvm.org/D91157#2435844 try-job: aarch64-msvc-* try-job: arm-android try-job: dist-android try-job: dist-aarch64-llvm-mingw try-job: dist-aarch64-msvc try-job: dist-various-* try-job: test-various

Handle macro invocation in attribute during parse ``` error: expected a literal (`1u8`, `1.0f32`, `"string"`, etc.) here, found macro `concat` --> $DIR/macro-in-attribute.rs:4:21 | LL | #[deprecated(note = concat!("a", "b"))] | ^^^^^^^^^^^^^^^^^ macros are not allowed here ``` Fix rust-lang#146325.

unstable proc_macro tracked::* rename/restructure Picking up what should be the uncontroversial part of rust-lang#87173 (closed due to inactivity over two years ago). Part of rust-lang#99515. - move `proc_macro::tracked_env::var` to `proc_macro::tracked::env_var` - move `proc_macro::tracked_path::path` to `proc_macro::tracked::path` - change the argument of `proc_macro::tracked::path` from `AsRef<str>` to `AsRef<Path>`.

…e-code, r=davidtwco attempt to fix unreachable code regression For some reason it works, it checks function output type and suppress warning if type is uninhabited ~~This double negations in code breaks my mind actually~~ I'd love to revisit this part in future and try to find a proper solution maybe, but for now I feel like it's enough before release to fix the issue? I really wonder what team does think, especially `@cjgillot` and other people who are more confident in this part of compiler than I do I tried a lot of things here, it's only approach that pass all tests included new regression one fixes rust-lang#149571 r? compiler

…oieni Mirror `ubuntu:24.04` on ghcr The miri job wants to use it (https://rust-lang.zulipchat.com/#narrow/channel/242791-t-infra/topic/Adding.20a.20C.2B.2B.20dependency.20to.20Miri.3F/with/560654845), and sooner or later we will likely migrate our CI to it too. r? `@marcoieni`

matthiaskrgr · 2025-12-09T16:37:31Z

@bors r+ rollup=never p=5

bors · 2025-12-09T16:37:33Z

📌 Commit a00807e has been approved by matthiaskrgr

It is now in the queue for this repository.

Rollup of 5 pull requests Successful merges: - #144938 (Enable `outline-atomics` by default on more AArch64 platforms) - #146579 (Handle macro invocation in attribute during parse) - #149400 (unstable proc_macro tracked::* rename/restructure) - #149664 (attempt to fix unreachable code regression ) - #149806 (Mirror `ubuntu:24.04` on ghcr) Failed merges: - #149789 (Cleanup in the attribute parsers) r? `@ghost` `@rustbot` modify labels: rollup

bors · 2025-12-09T19:37:27Z

⌛ Testing commit a00807e with merge 5d4c935...

bors · 2025-12-09T21:29:53Z

💔 Test failed - checks-actions

matthiaskrgr · 2025-12-09T21:32:35Z

@bors retry

rust-log-analyzer · 2025-12-09T21:34:28Z

The job x86_64-msvc-ext1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

Command `D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage1-tools-bin\cargotest.exe D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage2-tools-bin\cargo.exe D:\a\rust\rust\build\ct` failed with exit code 101
Created at: src\bootstrap\src\core\build_steps\tool.rs:1612:23
Executed at: src\bootstrap\src\core\build_steps\test.rs:323:29

Command has failed. Rerun with -v to see more details.
Bootstrap failed while executing `--stage 2 test src/tools/cargotest src/tools/cargo`
Build completed unsuccessfully in 1:41:43
  local time: Tue Dec  9 21:28:54 CUT 2025
  network time: Tue, 09 Dec 2025 21:28:54 GMT
##[error]Process completed with exit code 1.

bors · 2025-12-09T22:05:55Z

⌛ Testing commit a00807e with merge 5f1173b...

bors · 2025-12-10T01:16:02Z

☀️ Test successful - checks-actions
Approved by: matthiaskrgr
Pushing 5f1173b to main...

rust-timer · 2025-12-10T01:17:30Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#144938	Enable `outline-atomics` by default on more AArch64 platfor…	`b583aa25de6aa4b4cec42caa2ebd2e284e1a76f3` (link)
#146579	Handle macro invocation in attribute during parse	`baf3ab6a192292c14b4e9d83e9b01ca038e61d9c` (link)
#149400	unstable proc_macro tracked::* rename/restructure	`f04e1d2b95028b06246e9541f612c562be4d4bae` (link)
#149664	attempt to fix unreachable code regression	`2fe9b5185e04298df9b0f3c1bb5e9201d846633a` (link)
#149806	Mirror `ubuntu:24.04` on ghcr	`b1cade7750664966db808a8e533a4599c6b4113f` (link)

previous master: c61a3a44d1

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

github-actions · 2025-12-10T01:18:52Z

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 c61a3a4 (parent) -> 5f1173b (this PR)

Test differences

Show 32 test diffs

Stage 1

[ui] tests/ui/parser/macro/expr-in-attribute.rs: [missing] -> pass (J1)
[ui] tests/ui/parser/macro/macro-in-attribute.rs: [missing] -> pass (J1)
[ui] tests/ui/uninhabited/uninhabited-unreachable-warning-149571.rs: [missing] -> pass (J1)

Stage 2

[ui] tests/ui/parser/macro/expr-in-attribute.rs: [missing] -> pass (J0)
[ui] tests/ui/parser/macro/macro-in-attribute.rs: [missing] -> pass (J0)
[ui] tests/ui/uninhabited/uninhabited-unreachable-warning-149571.rs: [missing] -> pass (J0)

Additionally, 26 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 5f1173bb2b0a7012640bd5383c61b433b16a452d --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

aarch64-apple: 10755.1s -> 8358.3s (-22.3%)
pr-check-1: 2020.4s -> 1696.2s (-16.0%)
aarch64-gnu-debug: 4470.0s -> 3832.5s (-14.3%)
x86_64-gnu-llvm-20: 2836.2s -> 2433.7s (-14.2%)
dist-x86_64-apple: 9308.9s -> 8004.3s (-14.0%)
x86_64-gnu-gcc: 3400.4s -> 2966.0s (-12.8%)
dist-aarch64-msvc: 6059.8s -> 5295.4s (-12.6%)
x86_64-gnu-llvm-20-3: 6517.7s -> 5726.8s (-12.1%)
x86_64-gnu-tools: 3613.6s -> 3217.4s (-11.0%)
aarch64-gnu-llvm-20-1: 3743.4s -> 3335.9s (-10.9%)

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 · 2025-12-10T01:57:51Z

Finished benchmarking commit (5f1173b): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

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)	0.2%	[0.1%, 0.3%]	18
Regressions ❌ (secondary)	0.3%	[0.2%, 0.5%]	13
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.6%, -0.3%]	3
All ❌✅ (primary)	0.2%	[0.1%, 0.3%]	18

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results (primary -2.7%)

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)	-2.7%	[-2.8%, -2.5%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.7%	[-2.8%, -2.5%]	2

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 471.772s -> 471.137s (-0.13%)
Artifact size: 389.00 MiB -> 389.02 MiB (0.00%)

Skgland and others added 21 commits November 26, 2025 22:44

move and rename proc_macro::tracked_{env::var,path::path}

72076c6

change proc_macro::tracked::path to take an AsRef<Path> instead of an…

8d8d702

… AsRef<str>

fix tests

f4296bc

fix tests/run-make/track-path-dep-info attempt 2

3f67246

compiler-builtins: Change gating for outline atomic symbols

0030e8a

Build outline atomic symbols on all targets that have `outline-atomics` enabled, rather than only on Linux. Since this is no longer OS-specific, also rename the module.

Enable outline-atomics by default on AArch64 Windows platforms

1ed1b6e

Windows has a similar flag `/forceInterlockedFunctions`, which uses names such as `_InterlockedAdd64_rel`.

Enable outline-atomics by default on AArch64 Android

c455903

Per LLVM commit c5e7e64 ("[AArch64][Clang][Linux] Enable out-of-line atomics by default.") [1], Clang enables these on Android. Thus, do the same in Rust. [1]: llvm/llvm-project@c5e7e649d537067de

Enable outline-atomics by default on AArch64 Fuchsia

21525f8

Clang has done this by default since LLVM commit 1a963d3 ("[Driver] Make -moutline-atomics default for aarch64-fuchsia targets"), [1], so do the same here. [1]: llvm/llvm-project@1a963d3

Enable outline-atomics by default on AArch64 OpenBSD

66c150c

Clang has recently started doing this, as of LLVM commit 5d774ec8d183 ("[Driver] Enable outline atomics for OpenBSD/aarch64") [1]. Thus, do the same here. [1]: llvm/llvm-project@5d774ec

Handle macro invocation in attribute during parse

01e2cf8

``` error: expected a literal (`1u8`, `1.0f32`, `"string"`, etc.) here, found macro `concat` --> $DIR/macro-in-attribute.rs:4:21 | LL | #[deprecated(note = concat!("a", "b"))] | ^^^^^^^^^^^^^^^^^ macros are not allowed here ```

Rework attribute recovery logic

0b0e826

review comment

c1500f9

fix test

761cb57

Mirror ubuntu:24.04 on ghcr

75df299

add check for uninhabited types along side never

2a2da78

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 9, 2025

bors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Dec 9, 2025

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 9, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Dec 10, 2025

bors merged commit 5f1173b into rust-lang:main Dec 10, 2025
12 checks passed

rustbot added this to the 1.94.0 milestone Dec 10, 2025

rustbot added the perf-regression Performance regression. label Dec 10, 2025

This was referenced Dec 10, 2025

Allow passing expr metavariable to cfg #146961

Open

Port doc attributes to new attribute API #149645

Open

Cleanup in the attribute parsers #149789

Open

Rollup of 5 pull requests #149818

Rollup of 5 pull requests #149818

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Test differences

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Stage 2

Job duration changes

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rust-timer commented Dec 10, 2025

Overall result: ❌✅ regressions and improvements - please read the text below

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Cycles

Binary size

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