use CursorRef more

[klensy]

This allows skipping clone of TreeAndSpacing (and TokenTree).

[rust-highfive]

r? @lcnr

(rust-highfive has picked a reviewer for you, use r? to override)

[lcnr]

r? rust-lang/compiler

[klensy]

Ha, diff became short, actually. Will squash.

[klensy]

I don't see any comment why HashStable and PartialEq implementations use only TokenTree and not Spacing part of TokenStream. If it's intended it should be noted, otherwise it's possible bug?
https://github.com/rust-lang/rust/blob/e57e13878687beeb844ed3df127207f58457041d/compiler/rustc_ast/src/tokenstream.rs#L305-L308
https://github.com/rust-lang/rust/blob/e57e13878687beeb844ed3df127207f58457041d/compiler/rustc_ast/src/tokenstream.rs#L105-L114
https://github.com/rust-lang/rust/blob/e57e13878687beeb844ed3df127207f58457041d/compiler/rustc_ast/src/tokenstream.rs#L387-L391

[klensy]

@rustbot ready

[petrochenkov]

If it's intended it should be noted, otherwise it's possible bug?

It's quite possible that it's a source of bugs.

[petrochenkov]

@bors r+

[bors]

📌 Commit 05f459e has been approved by petrochenkov

[bors]

⌛ Testing commit 05f459e with merge 6913c74...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing 6913c74 to master...

[rust-timer]

Finished benchmarking commit (6913c74): comparison url.

Instruction count

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

Max RSS (memory usage)

Results

• Primary benchmarks: no relevant changes found
• Secondary benchmarks: mixed results

	Regressions 😿 (primary)	Regressions 😿 (secondary)	Improvements 🎉 (primary)	Improvements 🎉 (secondary)	All 😿 🎉 (primary)
count1	0	4	0	1	0
mean2	N/A	2.6%	N/A	-2.6%	N/A
max	N/A	5.5%	N/A	-2.6%	N/A

Cycles

Results

• Primary benchmarks: mixed results
• Secondary benchmarks: 🎉 relevant improvement found

	Regressions 😿 (primary)	Regressions 😿 (secondary)	Improvements 🎉 (primary)	Improvements 🎉 (secondary)	All 😿 🎉 (primary)
count1	2	0	2	1	4
mean2	1.4%	N/A	-2.7%	-2.3%	-0.7%
max	1.4%	N/A	-3.7%	-2.3%	-3.7%

If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf.

@rustbot label: -perf-regression

Footnotes

1. number of relevant changes ↩ ↩²

2. the arithmetic mean of the percent change ↩ ↩²

[nnethercote]

Cursor has this comment:

// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.

Should that be removed now?

[klensy]

Cursor has this comment:

// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.

Should that be removed now?

Yeah, looks like there no more easy to replace places for CursorRef.