Lint overlapping ranges as a separate pass

[Nadrieril]

This reworks the overlapping_range_endpoints lint. My motivations are:

• It was annoying to have this lint entangled with the exhaustiveness algorithm, especially wrt librarification;
• This makes the lint behave consistently.

Here's the consistency story. Take the following matches:

match(0u8,true){(0..=10,true) => {}(10..20,true) => {}(10..20,false) => {}
_ => {}}match(true,0u8){(true,0..=10) => {}(true,10..20) => {}(false,10..20) => {}
_ => {}}

There are two semantically consistent options: option 1 we lint all overlaps between the ranges, option 2 we only lint the overlaps that could actually occur (i.e. the ones with true). Option 1 is what this PR does. Option 2 is possible but would require the exhaustiveness algorithm to track more things for the sake of the lint. The status quo is that we're inconsistent between the two.

Option 1 generates more false postives, but I prefer it from a maintainer's perspective. I do think the difference is minimal; cases where the difference is observable seem rare.

This PR adds a separate pass, so this will have a perf impact. Let's see how bad, it looked ok locally.

[rustbot]

r? @petrochenkov

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

[Nadrieril]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8872fef with merge 600bb87...

[bors]

☀️ Try build successful - checks-actions
Build commit: 600bb87 (600bb87ab7496fbcc1fa8f1c16a7783c96786b7c)

[petrochenkov]

r? compiler

[rust-timer]

Finished benchmarking commit (600bb87): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

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

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.2%, 0.9%]	11
Regressions ❌ (secondary)	0.3%	[0.1%, 0.3%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.4%	[0.2%, 0.9%]	11

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)	1.9%	[1.2%, 2.5%]	2
Regressions ❌ (secondary)	2.5%	[0.8%, 4.7%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.9%	[1.2%, 2.5%]	2

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: 624.729s -> 625.048s (0.05%)
Artifact size: 305.51 MiB -> 305.53 MiB (0.01%)

[Nadrieril]

As expected, consistent small regression on the pattern-heavy benchmarks. Feels worth it for how easier it'll make my life 😇

[Nadrieril]

#116734 got merged and uses a similar per-column traversal, so I factored that out. Let's check this doesn't affect perf.

@bors try @rust-timer queue

[bors]

⌛ Trying commit 775726f with merge 3bcf078...

[bors]

☀️ Try build successful - checks-actions
Build commit: 3bcf078 (3bcf0783f1b9e4d91c7eec3157df168ce0a6c6b6)

[rust-timer]

Finished benchmarking commit (3bcf078): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

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

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.2%, 0.9%]	11
Regressions ❌ (secondary)	0.3%	[0.3%, 0.4%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.4%	[0.2%, 0.9%]	11

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)	2.2%	[1.7%, 2.7%]	2
Regressions ❌ (secondary)	2.9%	[0.9%, 6.2%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.0%	[-3.5%, -1.0%]	4
All ❌✅ (primary)	2.2%	[1.7%, 2.7%]	2

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: 632.219s -> 629.702s (-0.40%)
Artifact size: 301.96 MiB -> 304.02 MiB (0.68%)

[Nadrieril]

@davidtwco Do you have capacity to review this? I can reroll reviewer selection if not

[davidtwco]

Apologies for the delay in getting to this, the false positives here are a shame, but given that were inconsistent before, I think it's okay. LGTM.

[davidtwco]

@bors r+

[bors]

📌 Commit 3fa2e71 has been approved by davidtwco

It is now in the queue for this repository.

[Nadrieril]

Thank you!

[bors]

⌛ Testing commit 3fa2e71 with merge 9d6d5d4...

[bors]

☀️ Test successful - checks-actions
Approved by: davidtwco
Pushing 9d6d5d4 to master...

[rust-timer]

Finished benchmarking commit (9d6d5d4): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

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)	0.3%	[0.2%, 1.0%]	19
Regressions ❌ (secondary)	0.3%	[0.3%, 0.3%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.2%, 1.0%]	19

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)	1.5%	[1.5%, 1.5%]	1
Regressions ❌ (secondary)	1.7%	[1.1%, 2.5%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.5%	[1.5%, 1.5%]	1

Cycles

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)	2.6%	[2.3%, 3.1%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.7%	[-0.7%, -0.7%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 635.341s -> 636.748s (0.22%)
Artifact size: 304.51 MiB -> 304.50 MiB (-0.00%)