#124141 preliminaries

[nnethercote]

Preliminary changes required to start removing Nonterminal (#124141).

r? @petrochenkov

[rustbot]

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

[nnethercote]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 3266ef9 with merge feea15e...

[bors]

☀️ Try build successful - checks-actions
Build commit: feea15e (feea15e1db26b2aeb01e686e25fdef124e5e2b2c)

[rust-timer]

Finished benchmarking commit (feea15e): comparison URL.

Overall result: ❌ regressions - please read the text below

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.5%]	59
Regressions ❌ (secondary)	0.3%	[0.1%, 0.6%]	33
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	2
All ❌✅ (primary)	0.2%	[0.1%, 0.5%]	59

Max RSS (memory usage)

Results (secondary 4.5%)

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)	4.5%	[3.2%, 5.7%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary 9.7%)

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)	9.7%	[9.4%, 9.9%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.0%)

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)	0.0%	[0.0%, 0.0%]	8
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[0.0%, 0.0%]	8

Bootstrap: 781.474s -> 782.28s (0.10%)
Artifact size: 335.25 MiB -> 335.33 MiB (0.03%)

[petrochenkov]

Quite a few perf regressions, do you know what is the reason? Are they avoidable?
@rustbot author

[nnethercote]

The regressions are smaller when I benchmark locally, so it's hard to tell exactly what's happening. But I suspect there are two possible causes:

• We used to just skip all invisible delimiters, but now we only skip some, which involves an extra check. This is most important in TokenCursor::inlined_next which is very hot. This is impossible to avoid.
• The extra cases added to can_begin_*/may_be_* will make those functions slightly slower. Once Nonterminal is removed some of the old cases will be removed, so any effect here should eventually disappear.

The regressions are mostly in incr-unchanged runs, where parsing/expansion performance changes are magnified. I can't see how to avoid these for now.

@rustbot label: +perf-regression-triaged

[nnethercote]

@rustbot ready

[petrochenkov]

r=me after removing the remaining glob imports (#132629 (comment)).
@rustbot author

[nnethercote]

I addressed all the comments.

@bors r=petrochenkov

[bors]

📌 Commit 03159d4 has been approved by petrochenkov

It is now in the queue for this repository.

[bors]

⌛ Testing commit 03159d4 with merge 31e990b61226b63aeab7a1a9318ceb1e05d498a4...

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

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

[bors]

💔 Test failed - checks-actions

[matthiaskrgr]

Run src/ci/scripts/setup-upstream-remote.sh
Configuring https://github.com/rust-lang/rust remote as upstream.
fatal: unable to access 'https://github.com/rust-lang/rust/': Failed to connect to github.com port 443: Connection timed out

@bors retry Failed to connect to github.com port 443: Connection timed out

[bors]

⌛ Testing commit 03159d4 with merge acafcf5...

[rust-log-analyzer]

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

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

---- [run-make] tests\run-make\avr-rjmp-offset stdout ----

error: rmake recipe failed to complete
status: exit code: 1
command: "C:\\a\\rust\\rust\\build\\x86_64-pc-windows-gnu\\test\\run-make\\avr-rjmp-offset\\rmake.exe"
--- stderr -------------------------------
command failed at line 29
command failed at line 29
Command { cmd: "C:\\a\\rust\\rust\\build\\x86_64-pc-windows-gnu\\stage2\\bin\\rustc.exe" "-L" "C:\\a\\rust\\rust\\build\\x86_64-pc-windows-gnu\\test\\run-make\\avr-rjmp-offset\\rmake_out" "avr-rjmp-offsets.rs" "-Copt-level=s" "-Cpanic=abort" "--target=avr-unknown-gnu-atmega328" "-Clinker=rust-lld" "-Clink-arg=--entry=main" "-o" "compiled", stdin_buf: None, stdin: None, stdout: None, stderr: None, drop_bomb: DropBomb { command: "C:\\a\\rust\\rust\\build\\x86_64-pc-windows-gnu\\stage2\\bin\\rustc.exe", defused: true, armed_location: Location { file: "C:\\a\\rust\\rust\\tests\\run-make\\avr-rjmp-offset\\rmake.rs", line: 16, col: 5 } }, already_executed: true }
output status: `exit code: 1`
=== STDOUT ===


=== STDERR ===
error: linking with `rust-lld` failed: exit code: 0xc0000374
error: linking with `rust-lld` failed: exit code: 0xc0000374
  |
  = note: "rust-lld" "-flavor" "gnu" "C:\\a\\_temp\\msys64\\tmp\\rustc3Mz6if\\symbols.o" "compiled.avr_rjmp_offsets.ab053966543a1f9f-cgu.0.rcgu.o" "--as-needed" "-Bdynamic" "-z" "noexecstack" "-L" "C:\\a\\rust\\rust\\build\\x86_64-pc-windows-gnu\\test\\run-make\\avr-rjmp-offset\\rmake_out" "-o" "compiled" "--gc-sections" "--entry=main"

error: aborting due to 1 previous error
------------------------------------------

[bors]

💔 Test failed - checks-actions

[nnethercote]

@bors retry because it smells like a random linker crash

[bors]

⌛ Testing commit 03159d4 with merge 717f5df2c308dfb4b7b8e6c002c11fe8269c4011...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing 717f5df to master...

[rust-timer]

Finished benchmarking commit (717f5df): 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

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.1%, 0.3%]	29
Regressions ❌ (secondary)	0.3%	[0.2%, 0.4%]	16
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.3%]	5
All ❌✅ (primary)	0.2%	[0.1%, 0.3%]	29

Max RSS (memory usage)

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

Cycles

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

Binary size

Results (primary 0.0%)

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)	0.0%	[0.0%, 0.0%]	8
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.0%	[0.0%, 0.0%]	8

Bootstrap: 796.195s -> 795.947s (-0.03%)
Artifact size: 335.92 MiB -> 336.01 MiB (0.03%)