Only golden arches

[workingjubilee]

A number of tests in the test suite have applied the somewhat comedic practice of ignoring every single target architecture that rustc has ever supported. This is silly, when they are clearly tests built around certain assumptions, primarily of the x86-64 architecture, or in one case when they are only relevant for a handful of 32-bit targets. This has even resulted, in one case, in the same architecture being ignored twice!

Document these better, and use a "revision + only-arch" idiom in the test headers to denote the "golden arches" that actually pass these tests.

[rustbot]

r? @compiler-errors

(rustbot has picked a reviewer for you, use r? to override)

[ChrisDenton]

Huh, I didn't know only-* was additive like that.

[workingjubilee]

@ChrisDenton It is not.

This pattern requires the use of revisions. The revision only applies a directive for that revision, and reruns the test (including ignoring it) for each revision.

[compiler-errors]

@bors r+

[bors]

📌 Commit 20ebbf4 has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit 20ebbf4 with merge 03b8b50...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing 03b8b50 to master...

[rust-timer]

Finished benchmarking commit (03b8b50): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.4%	[-5.4%, -5.4%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.6%	[-2.6%, -2.6%]	1
All ❌✅ (primary)	-	-	0

Cycles

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

Binary size

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

Bootstrap: 653.862s -> 652.303s (-0.24%)

[RalfJung]

Do multiple "only" not have the semantics "test runs if any of the architectures match"? That is the semantics I would expect (and it is what the ui-test crate does).

[workingjubilee]

Hmm, when I talked with someone who knows more about ui_test and compiletest than me, they said it didn't do unions of only-*, but now I'm hearing conflicting reports so...!

[RalfJung]

Ah, seems like I was wrong for ui_test

https://github.com/oli-obk/ui_test/blob/5065d1c71e3382e65f422919d020843fc63b6914/src/lib.rs#L1120

The revisions are a clever trick. :)