Rollup of 6 pull requests #144718

Zalathar · 2025-07-31T05:42:03Z

Successful merges:

Implement push_mut #135975 (Implement push_mut)
Fix Box allocator drop elaboration #143672 (Fix Box allocator drop elaboration)
Implement support for become and explicit tail call codegen for the LLVM backend #144232 (Implement support for become and explicit tail call codegen for the LLVM backend)
coverage: Re-land "Enlarge empty spans during MIR instrumentation" #144663 (coverage: Re-land "Enlarge empty spans during MIR instrumentation")
Only extract lang items once in codegen_fn_attrs #144685 (Only extract lang items once in codegen_fn_attrs)
Move rustc_middle::parameterized #144717 (Move rustc_middle::parameterized)

r? @ghost
@rustbot modify labels: rollup

Create a similar rollup

…nd the LLVM codegen backend.

This allows us to assume that coverage spans will only be discarded during codegen in very unusual situations.

It's only used there.

Implement `push_mut` Implementation of rust-lang#135974.

… r=oli-obk Fix Box allocator drop elaboration New version of rust-lang#131146. Clearing Box's drop flag after running its destructor can cause it to skip dropping its allocator, so just don't. Its cleared by the drop ladder code afterwards already. Unlike the last PR this also handles other types with destructors properly, in the event that we can have open drops on them in the future (by partial initialization or DerefMove or something). Finally, I also added tests for the interaction with async drop here but I discovered rust-lang#143658, so one of the tests has a `knownbug` annotation. Not sure if it should be in this PR at all though. Fixes rust-lang#131082 r? wesleywiser - prev. reviewer

…fleLapkin Implement support for `become` and explicit tail call codegen for the LLVM backend This PR implements codegen of explicit tail calls via `become` in `rustc_codegen_ssa` and support within the LLVM backend. Completes a task on (rust-lang#112788). This PR implements all the necessary bits to make explicit tail calls usable, other backends have received stubs for now and will ICE if you use `become` on them. I suspect there is some bikeshedding to be done on how we should go about implementing this for other backends, but it should be relatively straightforward for GCC after this is merged. During development I also put together a POC bytecode VM based on tail call dispatch to test these changes out and analyze the codegen to make sure it generates expected assembly. That is available [here](https://github.com/xacrimon/tcvm).

coverage: Re-land "Enlarge empty spans during MIR instrumentation" This allows us to assume that coverage spans will only be discarded during codegen in very unusual situations. --- This seemingly-simple change has a rather messy history: - rust-lang#140847 - rust-lang#141650 - rust-lang#144298 - rust-lang#144480 Since then, a number of related changes have landed that should make it reasonable to try again: - rust-lang#144530 - rust-lang#144560 - rust-lang#144616 In particular, we have multiple fixes/mitigations, and a confirmed regression test for the original bug that is not triggered by re-landing the changes in this PR.

…fflelapkin Only extract lang items once in codegen_fn_attrs This one should be obvious. These two extraction points used to be far apart but now that they're refactored to be close it was rather obvious we're just doing double work.... r? ``@WaffleLapkin`` Buils on rust-lang#144655

…terized, r=compiler-errors Move `rustc_middle::parameterized` It doesn't need to be in `rustc_middle`. r? `@compiler-errors`

Zalathar · 2025-07-31T05:42:14Z

@bors r+ rollup=never p=5

bors · 2025-07-31T05:42:16Z

📌 Commit 9c6a618 has been approved by Zalathar

It is now in the queue for this repository.

bors · 2025-07-31T05:43:59Z

⌛ Testing commit 9c6a618 with merge cc0a5b7...

bors · 2025-07-31T08:53:24Z

☀️ Test successful - checks-actions
Approved by: Zalathar
Pushing cc0a5b7 to master...

rust-timer · 2025-07-31T08:55:09Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#135975	Implement `push_mut`	`de3e33fdc1bfbdb0cb947912ff0859fe677a4054` (link)
#143672	Fix Box allocator drop elaboration	`e1ed8e286ae6c46948a78f9228d61c9d61917b2c` (link)
#144232	Implement support for `become` and explicit tail call codeg…	`22613ede6f0d2525afbdbb06257cd3abc5d5a02e` (link)
#144663	coverage: Re-land "Enlarge empty spans during MIR instrumen…	`0f39cf639e7b09ecbe2d8fe424c52a1df12a2a92` (link)
#144685	Only extract lang items once in codegen_fn_attrs	`61d82f123698f60c4c1b999ada79abdbf7d784fd` (link)
#144717	Move `rustc_middle::parameterized`	`f187546e3442f1ccab0a2c98ede874f688b45c8d` (link)

previous master: 32e7a4b92b

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 · 2025-07-31T08:56:44Z

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 32e7a4b (parent) -> cc0a5b7 (this PR)

Test differences

Show 268 test diffs

Stage 1

[codegen] tests/codegen-llvm/become-musttail.rs: [missing] -> pass (J1)
[mir-opt] tests/mir-opt/box_conditional_drop_allocator.rs: [missing] -> pass (J1)
[ui] tests/ui/async-await/async-drop/async-drop-box-allocator.rs: [missing] -> pass (J1)
[ui] tests/ui/async-await/async-drop/async-drop-box.rs: [missing] -> pass (J1)
[ui] tests/ui/drop/box-conditional-drop-allocator.rs: [missing] -> pass (J1)
[ui] tests/ui/explicit-tail-calls/recursion-etc.rs: [missing] -> pass (J1)

Stage 2

[ui] tests/ui/async-await/async-drop/async-drop-box-allocator.rs: [missing] -> pass (J0)
[ui] tests/ui/async-await/async-drop/async-drop-box.rs: [missing] -> pass (J0)
[ui] tests/ui/drop/box-conditional-drop-allocator.rs: [missing] -> pass (J0)
[ui] tests/ui/explicit-tail-calls/recursion-etc.rs: [missing] -> pass (J0)
[mir-opt] tests/mir-opt/box_conditional_drop_allocator.rs: [missing] -> pass (J2)
[codegen] tests/codegen-llvm/become-musttail.rs: [missing] -> pass (J3)

Additionally, 256 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 cc0a5b73053c62a3df5f84b3ee85079c9b65fa87 --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

x86_64-apple-2: 4392.8s -> 7293.9s (66.0%)
x86_64-apple-1: 9118.2s -> 6397.5s (-29.8%)
aarch64-apple: 6311.0s -> 4450.5s (-29.5%)
dist-apple-various: 4489.3s -> 5494.2s (22.4%)
dist-x86_64-windows-gnullvm: 6076.0s -> 7234.0s (19.1%)
dist-x86_64-apple: 12320.3s -> 10617.4s (-13.8%)
dist-aarch64-msvc: 5718.7s -> 4976.2s (-13.0%)
dist-aarch64-apple: 7855.6s -> 7047.3s (-10.3%)
dist-x86_64-musl: 7209.6s -> 7843.9s (8.8%)
dist-sparcv9-solaris: 4951.1s -> 5323.8s (7.5%)

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 · 2025-07-31T12:05:27Z

Finished benchmarking commit (cc0a5b7): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -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)	-	-	0
Improvements ✅ (primary)	-0.5%	[-0.6%, -0.5%]	2
Improvements ✅ (secondary)	-0.3%	[-1.0%, -0.1%]	8
All ❌✅ (primary)	-0.5%	[-0.6%, -0.5%]	2

Max RSS (memory usage)

Results (primary 7.0%, secondary -2.2%)

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

	mean	range	count
Regressions ❌ (primary)	7.0%	[7.0%, 7.0%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.2%]	1
All ❌✅ (primary)	7.0%	[7.0%, 7.0%]	1

Cycles

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)	3.1%	[2.2%, 4.0%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.1%	[2.2%, 4.0%]	2

Binary size

Results (primary 0.1%, secondary 0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.3%]	32
Regressions ❌ (secondary)	0.1%	[0.0%, 0.2%]	7
Improvements ✅ (primary)	-0.2%	[-0.4%, -0.0%]	3
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[-0.4%, 0.3%]	35

Bootstrap: 467.812s -> 468.739s (0.20%)
Artifact size: 376.72 MiB -> 376.79 MiB (0.02%)

beepster4096 and others added 16 commits July 25, 2025 13:19

fix box destructor generation

dad9826

async drop tests for box

c6d740d

span_bug instead of handling currently impossible drop case

ba55f20

add //@ needs-unwind to test

ccc2f78

Implement support for explicit tail calls in the MIR block builders a…

a448837

…nd the LLVM codegen backend.

coverage: Re-land "Enlarge empty spans during MIR instrumentation"

2e6f4a5

This allows us to assume that coverage spans will only be discarded during codegen in very unusual situations.

only extract lang items once

3fe0e24

Implement push_mut

3ccfa14

Remove unused ParameterizedOverTcx impls.

0a3eb2f

Move rustc_middle::parameterized to rustc_metadata.

66fd421

It's only used there.

Rollup merge of rust-lang#135975 - balt-dev:master, r=tgross35

dc8aec4

Implement `push_mut` Implementation of rust-lang#135974.

Rollup merge of rust-lang#144717 - nnethercote:mv-rustc_middle-parame…

9c6a618

…terized, r=compiler-errors Move `rustc_middle::parameterized` It doesn't need to be in `rustc_middle`. r? `@compiler-errors`

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 Jul 31, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Jul 31, 2025

bors merged commit cc0a5b7 into rust-lang:master Jul 31, 2025
11 checks passed

rustbot added this to the 1.90.0 milestone Jul 31, 2025

Zalathar deleted the rollup-76lrtf2 branch July 31, 2025 08:56

bors mentioned this pull request Jul 31, 2025

make some vecdeque methods const #144612

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Rollup of 6 pull requests #144718

Rollup of 6 pull requests #144718

Zalathar commented Jul 31, 2025 •

edited by rustbot

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Rollup of 6 pull requests #144718

Rollup of 6 pull requests #144718

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Test differences

Stage 1

Stage 2

Job duration changes

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rust-timer commented Jul 31, 2025

Overall result: ✅ improvements - no action needed

Instruction count

Max RSS (memory usage)

Cycles

Binary size

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Zalathar commented Jul 31, 2025 •

edited by rustbot

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