Consolidate LLVM skip in check builds in bootstrap

[Kobzol]

Before it was distributed amongst two places, which made it harder to follow the logic, and the RUST_CHECK logic was also applied for anything being built, even though it is only relevant for rustc itself. This PR centralizes the handling, and also enables it for doc builds.

So ./x doc compiler now doesn't require building LLVM 🎉

r? jieyouxu

[jieyouxu]

Thanks, you can r=me after (or before) #161290

View changes since this review

[jieyouxu]

@bors rollup=never note="bootstrap llvm skip logic"

[Kobzol]

@bors r=jieyouxu

Let's try to land this and see if there aren't any issues.

[rust-bors]

📌 Commit 9bff2d7 has been approved by jieyouxu

It is now in the queue for this repository.

[Kobzol]

@bors r-

[rust-bors]

This pull request was unapproved.

View changes since this unapproval

[Kobzol]

Surprise surprise, I didn't run bootstrap tests.

[Kobzol]

@bors r=jieyouxu

[rust-bors]

📌 Commit 45f342d has been approved by jieyouxu

It is now in the queue for this repository.

[rust-bors]

☀️ Test successful - CI
Approved by: jieyouxu
Duration: 3h 29m 10s
Pushing 17fd5b8 to main...

[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 344f790 (parent) -> 17fd5b8 (this PR)

Test differences

Show 3 test diffs

3 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 17fd5b8a37b6667b6cc137f3cc35f09759768a3b --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. i686-msvc-2: 1h 18m -> 2h 4m (+59.2%)
2. i686-gnu-nopt-2: 1h 33m -> 2h 17m (+46.9%)
3. x86_64-gnu-llvm-21-3: 1h 13m -> 1h 47m (+45.9%)
4. x86_64-gnu-stdlib-semver-check: 18m 4s -> 11m 29s (-36.4%)
5. pr-check-1: 41m 25s -> 28m (-32.4%)
6. i686-msvc-1: 2h 12m -> 2h 54m (+31.8%)
7. x86_64-gnu-gcc-core-tests: 17m 50s -> 12m 10s (-31.8%)
8. dist-x86_64-musl: 2h 18m -> 1h 34m (-31.6%)
9. x86_64-msvc-2: 1h 56m -> 2h 30m (+29.0%)
10. dist-x86_64-solaris: 1h 21m -> 1h 45m (+28.9%)

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]

Finished benchmarking commit (17fd5b8): comparison URL.

Overall result: ❌✅ regressions and 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)	0.3%	[0.3%, 0.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.5%	[-0.5%, -0.5%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 2.6%, secondary 0.5%)

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

	mean	range	count
Regressions ❌ (primary)	7.7%	[7.7%, 7.7%]	1
Regressions ❌ (secondary)	3.7%	[1.3%, 8.9%]	9
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-4.3%	[-5.2%, -2.1%]	6
All ❌✅ (primary)	2.6%	[-2.5%, 7.7%]	2

Cycles

Results (secondary -14.0%)

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-14.0%	[-24.3%, -3.0%]	8
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 475.673s -> 474.378s (-0.27%)
Artifact size: 403.60 MiB -> 402.85 MiB (-0.19%)