Mark span parent in def_collector.

[cjgillot]

The current device of marking spans with a parent def-id during lowering has been frustrating me for quite some time, as it's very easy to forget marking some spans.

This PR moves such marking to the def_collector, which is responsible for creating def-ids on partially expanded AST. This is much more robust as long as visitors are exhaustive.

r? ghost

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 95dc7f7 with merge ec84e1c...

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 585fe45 with merge 04122fb...

[bors]

☀️ Try build successful - checks-actions
Build commit: 04122fb (04122fbfda6e59dcf9c54b89353e6d1281c9ebc8)

[rust-timer]

Finished benchmarking commit (04122fb): comparison URL.

Overall result: ❌✅ regressions and improvements - 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)	1.0%	[0.2%, 2.5%]	163
Regressions ❌ (secondary)	1.3%	[0.3%, 6.2%]	77
Improvements ✅ (primary)	-2.6%	[-4.8%, -0.3%]	12
Improvements ✅ (secondary)	-0.5%	[-0.7%, -0.4%]	2
All ❌✅ (primary)	0.7%	[-4.8%, 2.5%]	175

Max RSS (memory usage)

Results (primary 0.3%, secondary -0.7%)

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)	2.1%	[1.4%, 2.6%]	6
Regressions ❌ (secondary)	4.2%	[4.0%, 4.6%]	3
Improvements ✅ (primary)	-2.4%	[-4.4%, -1.0%]	4
Improvements ✅ (secondary)	-3.6%	[-4.3%, -3.2%]	5
All ❌✅ (primary)	0.3%	[-4.4%, 2.6%]	10

Cycles

Results (primary 0.6%, secondary 3.2%)

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)	2.0%	[0.7%, 3.4%]	28
Regressions ❌ (secondary)	3.2%	[2.1%, 4.3%]	11
Improvements ✅ (primary)	-4.9%	[-6.0%, -1.4%]	7
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.6%	[-6.0%, 3.4%]	35

Binary size

Results (primary -0.2%, secondary -0.2%)

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)	0.1%	[0.0%, 0.2%]	7
Regressions ❌ (secondary)	0.1%	[0.1%, 0.2%]	6
Improvements ✅ (primary)	-0.2%	[-1.7%, -0.0%]	41
Improvements ✅ (secondary)	-0.3%	[-0.9%, -0.0%]	13
All ❌✅ (primary)	-0.2%	[-1.7%, 0.2%]	48

Bootstrap: 695.108s -> 697.834s (0.39%)
Artifact size: 327.55 MiB -> 327.54 MiB (-0.00%)

[cjgillot]

@petrochenkov do I need to add something to this PR to handle metavar spans, or is this pass enough?

[cjgillot]

@bors try @rust-timer queue

[bors]

☔ The latest upstream changes (presumably #143897) made this pull request unmergeable. Please resolve the merge conflicts.

[rustbot]

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

rustc_error_messages was changed

cc @davidtwco, @compiler-errors, @TaKO8Ki

[cjgillot]

I was thinking about the option 1., with an ad-hoc hierarchy. Although I didn't think about the need for stable representation. If SourceItemIds unambiguously map on DefIds later, when DefIds are already assigned, then DefPaths can be reused, I guess? In general, SourceItemIds should be as "temporary" as possible, and we start working in terms of DefIds instead, once they became available.

I'm trying to code that. That's quite a sizeable change, as this requires threading quite some state into the parser. Do you mind considering this PR first, and I'll post a follow-up with this change when I manage coding it?

[cjgillot]

@bors try @rust-timer queue

[rust-bors]

⌛ Trying commit d347d18 with merge d091832…

To cancel the try build, run the command @bors try cancel.

[rust-bors]

☀️ Try build successful (CI)
Build commit: d091832 (d09183296eff98da36fc9b67356b10cd003747f1, parent: ce5fdd7d42aba9a2925692e11af2bd39cf37798a)

[rust-timer]

Finished benchmarking commit (d091832): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

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.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@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)	1.8%	[0.1%, 11.4%]	136
Regressions ❌ (secondary)	1.1%	[0.0%, 11.5%]	83
Improvements ✅ (primary)	-0.5%	[-1.0%, -0.2%]	9
Improvements ✅ (secondary)	-0.5%	[-1.3%, -0.1%]	19
All ❌✅ (primary)	1.7%	[-1.0%, 11.4%]	145

Max RSS (memory usage)

Results (primary 1.9%, secondary 0.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.3%	[0.5%, 7.2%]	23
Regressions ❌ (secondary)	1.5%	[0.7%, 2.8%]	4
Improvements ✅ (primary)	-1.0%	[-1.6%, -0.4%]	3
Improvements ✅ (secondary)	-1.4%	[-1.7%, -1.1%]	2
All ❌✅ (primary)	1.9%	[-1.6%, 7.2%]	26

Cycles

Results (primary 7.1%, secondary 5.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	7.6%	[2.0%, 16.8%]	37
Regressions ❌ (secondary)	8.1%	[2.4%, 16.7%]	8
Improvements ✅ (primary)	-2.3%	[-2.5%, -2.1%]	2
Improvements ✅ (secondary)	-2.8%	[-2.9%, -2.8%]	2
All ❌✅ (primary)	7.1%	[-2.5%, 16.8%]	39

Binary size

Results (primary -0.1%, secondary -0.0%)

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)	0.2%	[0.2%, 0.2%]	4
Improvements ✅ (primary)	-0.1%	[-0.2%, -0.0%]	35
Improvements ✅ (secondary)	-0.0%	[-0.1%, -0.0%]	18
All ❌✅ (primary)	-0.1%	[-0.2%, -0.0%]	35

Bootstrap: 466.456s -> 465.739s (-0.15%)
Artifact size: 376.58 MiB -> 376.75 MiB (0.04%)