Cleanup in the attribute parsers

[JonathanBrouwer]

• Removes a bunch of unused lifetimes in the attribute parsers
• Creates two variants of PathParser, because we statically know which variant we're in

r? @jdonszelmann

[rustbot]

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

[JonathanBrouwer]

@bors try @rust-timer queue
Maybe the changes to the PathParser gain some perf?

[jdonszelmann]

Doubt it but we can try

[jdonszelmann]

@bors r+ rollup

was debating whether to cancel the perf run. I guess we can either rollup never and get the perf run later or keep the run going. If we keep the current one going then this pr can be part of the next roll-up and will use fewer ci resources and land quicker so I'm letting the perf run here continue and am explicitly rolling the pr up.

[bors]

📌 Commit 5c661ae has been approved by jdonszelmann

It is now in the queue for this repository.

[rust-bors]

☀️ Try build successful (CI)
Build commit: c626dd2 (c626dd2960debb0071cacde4d04165c310c5301c, parent: 5bc345055b06dc096b01bc6d1e0cbe92d3cc630e)

[rust-timer]

Finished benchmarking commit (c626dd2): comparison URL.

Overall result: ❌✅ regressions and 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)	0.1%	[0.1%, 0.1%]	1
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-0.2%, 0.1%]	2

Max RSS (memory usage)

Results (primary -1.4%, secondary 0.2%)

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)	3.2%	[3.2%, 3.2%]	1
Improvements ✅ (primary)	-1.4%	[-1.4%, -1.4%]	1
Improvements ✅ (secondary)	-1.2%	[-1.8%, -0.7%]	2
All ❌✅ (primary)	-1.4%	[-1.4%, -1.4%]	1

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: 473.701s -> 470.928s (-0.59%)
Artifact size: 389.02 MiB -> 389.00 MiB (-0.01%)

[jdonszelmann]

Nothing it seems

[JonathanBrouwer]

Agreed this is probably just noise, I don't think this needs to be rollup=never
@bors rollup=always