Remove most #[track_caller] from allocating Vec methods

[Noratrieb]

They cause significant binary size overhead while contributing little value.

closes #146963, see that issue for more details.

[rustbot]

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[tgross35]

Let's get a metric,

@bors2 try @rust-timer queue

I think it would be worth a comment somewhere in the vec module about the downsides here because it seems likely to eventually come up again.

[Noratrieb]

I've also reverted the part of #142728 that were related to allocation (and kept those related to normal panics).

[rust-bors]

☀️ Try build successful (CI)
Build commit: 53ff5a2 (53ff5a255756389b9bcba2fae16159745144eb13, parent: 6f34f4ee074ce0affc7bbf4e2c835f66cd576f13)

[rust-timer]

Finished benchmarking commit (53ff5a2): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@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
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	3
Improvements ✅ (primary)	-0.3%	[-0.5%, -0.1%]	26
Improvements ✅ (secondary)	-0.3%	[-0.4%, -0.1%]	23
All ❌✅ (primary)	-0.3%	[-0.5%, -0.1%]	26

Max RSS (memory usage)

Results (primary 3.0%)

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

	mean	range	count
Regressions ❌ (primary)	7.5%	[7.5%, 7.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.6%	[-1.6%, -1.6%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.0%	[-1.6%, 7.5%]	2

Cycles

Results (primary -2.5%, secondary 0.6%)

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)	2.7%	[2.7%, 2.7%]	1
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-1.5%	[-1.5%, -1.5%]	1
All ❌✅ (primary)	-2.5%	[-2.5%, -2.5%]	1

Binary size

Results (primary -0.4%, secondary -0.8%)

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)	-0.4%	[-1.0%, -0.0%]	95
Improvements ✅ (secondary)	-0.8%	[-1.4%, -0.0%]	56
All ❌✅ (primary)	-0.4%	[-1.0%, -0.0%]	95

Bootstrap: 471.619s -> 469.77s (-0.39%)
Artifact size: 388.14 MiB -> 387.68 MiB (-0.12%)

[tgross35]

Well that’s about the easiest set of wins we’ve had in a while 🎉. One note here is that the extend impls effectively take a callback, so I think this would give a less accurate panic location if the Iterator panics? Doesn’t seem concerning to me, that should basically never happen.

I still think it wouldn’t hurt to add a comment somewhere in vec/mod.rs to help ward off potential future contributions adding this back without knowing the history here. r=me after that

[Noratrieb]

I'm not sure anyone would find such a comment any more than they would find this PR. rustc-perf would certainly present a barrier, and I can surely hope that the next time there is more attention to the feature actually doing what people want 😨

[tgross35]

Fair enough,
@bors r+

[bors]

📌 Commit 9316d45 has been approved by tgross35

It is now in the queue for this repository.

[Zalathar]

Scheduling: Bumping some rollup=never PRs so they get a fair chance to compete with rollups.

@bors p=5

[bors]

⌛ Testing commit 9316d45 with merge c7f6aa2...

[bors]

☀️ Test successful - checks-actions
Approved by: tgross35
Pushing c7f6aa2 to master...

[github-actions]

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 848e674 (parent) -> c7f6aa2 (this PR)

Test differences

Show 834 test diffs

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

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard c7f6aa2869acdbf014d094c6e427e554e160b6db --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

1. dist-aarch64-linux: 6326.2s -> 8654.2s (36.8%)
2. dist-apple-various: 4821.2s -> 3523.4s (-26.9%)
3. arm-android: 5311.7s -> 6169.6s (16.2%)
4. x86_64-gnu-llvm-20: 2519.8s -> 2856.8s (13.4%)
5. x86_64-rust-for-linux: 2587.1s -> 2876.6s (11.2%)
6. aarch64-apple: 4655.1s -> 5128.9s (10.2%)
7. test-various: 4427.5s -> 4854.9s (9.7%)
8. i686-gnu-nopt-1: 7323.9s -> 7990.2s (9.1%)
9. dist-various-1: 4141.2s -> 3771.9s (-8.9%)
10. i686-gnu-1: 7772.6s -> 8434.3s (8.5%)

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]

Finished benchmarking commit (c7f6aa2): 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)	0.9%	[0.9%, 0.9%]	1
Regressions ❌ (secondary)	0.3%	[0.2%, 0.4%]	4
Improvements ✅ (primary)	-0.3%	[-0.7%, -0.1%]	37
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.0%]	26
All ❌✅ (primary)	-0.3%	[-0.7%, 0.9%]	38

Max RSS (memory usage)

Results (primary -1.8%, secondary -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)	-1.8%	[-3.7%, -0.5%]	5
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	-1.8%	[-3.7%, -0.5%]	5

Cycles

Results (primary 2.7%, secondary 3.0%)

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

	mean	range	count
Regressions ❌ (primary)	2.7%	[2.4%, 2.9%]	2
Regressions ❌ (secondary)	3.0%	[3.0%, 3.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.7%	[2.4%, 2.9%]	2

Binary size

Results (primary -0.4%, secondary -0.9%)

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)	-0.4%	[-1.3%, -0.0%]	104
Improvements ✅ (secondary)	-0.9%	[-1.4%, -0.1%]	56
All ❌✅ (primary)	-0.4%	[-1.3%, -0.0%]	104

Bootstrap: 471.059s -> 470.617s (-0.09%)
Artifact size: 388.15 MiB -> 387.65 MiB (-0.13%)