resolve: Make disambiguators for underscore bindings module-local (take 2)

[petrochenkov]

The difference with #144013 can be seen in the second commit.

Now we just keep a separate disambiguator counter in every Module, instead of a global counter in Resolver.
This will be ok for parallel import resolution because we'll need to lock the module anyway when updating resolutions and other fields in it.
And for external modules the disabmiguator could be just passed as an argument to define_extern, without using any cells or locks, once #143884 lands.

Unblocks #143884.

[rustbot]

r? @davidtwco

rustbot has assigned @davidtwco.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[petrochenkov]

r? @oli-obk as the reviewer of #144013

[oli-obk]

@bors r+ rollup

[bors]

📌 Commit e94b3da has been approved by oli-obk

It is now in the queue for this repository.

[matthiaskrgr]

@bors r-
think this failed here: #144325 (comment)

[petrochenkov]

@bors r- think this failed here: #144325 (comment)

I cannot reproduce this locally neither on Windows, nor on Linux.

[petrochenkov]

@bors try jobs=x86_64-apple-1

[rust-bors]

⌛ Trying commit 698fba9 with merge eba26fd…

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

[rust-bors]

💔 Test failed (CI). Failed jobs:

• bors build finished (web logs, extended logs)
• try - x86_64-apple-1 (web logs, extended logs)

[LorrensP-2158466]

I cannot reproduce this locally neither on Windows, nor on Linux.

I have a Mac M1. I can try and use Rosetta if you think that would help.

[petrochenkov]

The CI run on x86_64-apple-1 above didn't show the same error as in #144325 (comment), the "Building compiler artifacts (stage0 -> stage1, x86_64-apple-darwin)" step passed successfully.

I'll remove the debugging commit and r+ this again with rollup=never.

[petrochenkov]

I cannot reproduce this locally neither on Windows, nor on Linux.

I have a Mac M1. I can try and use Rosetta if you think that would help.

If you can reproduce the failure from #144325 (comment), it would be helpful, even if it's not related to this PR.

[LorrensP-2158466]

If you can reproduce the failure from #144325 (comment), it would be helpful, even if it's not related to this PR.

If it's not related, it would be too much of a hassle. I will have to install all x86_64 Apple packages that are used by Rust. That will take too much space and time 😆.

[petrochenkov]

@bors r=oli-obk rollup=never

[bors]

📌 Commit 4b55791 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 4b55791 with merge fc5af18...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing fc5af18 to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 3c30dbb (parent) -> fc5af18 (this PR)

Test differences

No test diffs found

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
test-dashboard fc5af1813307d25a84d633f21e2e53c9376eb547 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. dist-apple-various: 5640.3s -> 8446.7s (49.8%)
2. dist-aarch64-apple: 5827.1s -> 7014.0s (20.4%)
3. tidy: 102.7s -> 123.6s (20.3%)
4. pr-check-2: 2671.2s -> 2141.4s (-19.8%)
5. dist-x86_64-apple: 11237.3s -> 9040.1s (-19.6%)
6. x86_64-rust-for-linux: 2915.1s -> 2539.6s (-12.9%)
7. x86_64-gnu-llvm-19: 2827.5s -> 2506.2s (-11.4%)
8. dist-various-1: 3934.9s -> 4292.5s (9.1%)
9. i686-gnu-1: 8189.3s -> 7454.9s (-9.0%)
10. x86_64-gnu-tools: 3694.3s -> 3365.6s (-8.9%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (fc5af18): comparison URL.

Overall result: ❌ regressions - 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

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.1%, 0.7%]	17
Regressions ❌ (secondary)	0.3%	[0.0%, 0.6%]	21
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.4%	[0.1%, 0.7%]	17

Max RSS (memory usage)

Results (secondary -1.1%)

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)	2.5%	[2.5%, 2.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.8%	[-3.1%, -2.6%]	2
All ❌✅ (primary)	-	-	0

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: 468.586s -> 468.258s (-0.07%)
Artifact size: 374.68 MiB -> 374.68 MiB (-0.00%)

[petrochenkov]

Not sure why this is a small regression on tt-muncher and html5ever-0.31.0.
tt-muncher doesn't have any underscore imports at all.
The local cachegrinds diffs do not clarify it either.

tt-muncher:

12,205,855 ???:<rustc_expand::expand::MacroExpander>::fully_expand_fragment
-261,933 ./string/../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:__memcpy_avx_unaligned_erms
-29,451 ???:extent_try_coalesce_impl
27,560 ???:pa_dalloc
-23,471 ???:<rustc_resolve::Resolver>::build_reduced_graph_external
21,492 ???:<rustc_resolve::Resolver>::try_define
20,609 ???:<rustc_span::caching_source_map_view::CachingSourceMapView>::span_data_to_lines_and_cols
-20,234 ???:<rustc_parse::parser::Parser>::bump
19,810 ???:<hashbrown::raw::RawTable<(rustc_span::def_id::LocalDefId, alloc::vec::Vec<rustc_span::symbol::Ident>)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_span::def_id::LocalDefId, alloc::vec::Vec<rustc_span::symbol::Ident>, rustc_hash::FxBuildHasher>::{closure
-19,809 ???:<hashbrown::raw::RawTable<(rustc_ast::node_id::NodeId, rustc_hir::def::PartialRes)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_ast::node_id::NodeId, rustc_hir::def::PartialRes, rustc_hash::FxBuildHasher>::{closure
15,704 ???:<rustc_parse::parser::Parser>::parse_block_common
14,757 ???:<hashbrown::raw::RawTable<(rustc_ast::node_id::NodeId, usize)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_ast::node_id::NodeId, usize, rustc_hash::FxBuildHasher>::{closure
-13,806 ./nptl/./nptl/pthread_mutex_trylock.c:pthread_mutex_trylock@@GLIBC_2.34
12,404 ???:<rustc_ast_lowering::LoweringContext>::lower_expr_mut

html5ever-0.31.0:

6,005,394 ???:<rustc_expand::expand::MacroExpander>::fully_expand_fragment
234,545 ???:<rustc_resolve::Resolver>::try_define
187,120 ???:<hashbrown::raw::RawTable<(rustc_span::def_id::LocalDefId, alloc::vec::Vec<rustc_span::symbol::Ident>)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_span::def_id::LocalDefId, alloc::vec::Vec<rustc_span::symbol::Ident>, rustc_hash::FxBuildHasher>::{closure
-187,115 ???:<hashbrown::raw::RawTable<(rustc_ast::node_id::NodeId, rustc_hir::def::PartialRes)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_ast::node_id::NodeId, rustc_hir::def::PartialRes, rustc_hash::FxBuildHasher>::{closure
-137,848 ???:<rustc_resolve::Resolver>::build_reduced_graph_external
-117,050 ./string/../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:__memcpy_avx_unaligned_erms
-75,416 ???:<[A] as core::slice::cmp::SlicePartialEq<B>>::equal
37,716 ???:core::slice::<impl [T]>::starts_with
-32,828 ???:<rustc_span::symbol::Ident>::normalize_to_macros_2_0
24,301 ???:rustc_middle::ty::codec::encode_with_shorthand::<rustc_middle::query::on_disk_cache::CacheEncoder, rustc_middle::ty::Ty, <rustc_middle::query::on_disk_cache::CacheEncoder as rustc_middle::ty::codec::TyEncoder>::type_shorthands>
-24,244 ???:<rustc_parse::parser::Parser>::bump
18,642 ???:<rustc_parse::parser::Parser>::parse_block_common
17,604 ???:<rustc_span::caching_source_map_view::CachingSourceMapView>::span_data_to_lines_and_cols
-13,099 ???:<alloc::raw_vec::RawVec<&str>>::grow_one
13,033 ???:<alloc::raw_vec::RawVec<(usize, usize)>>::grow_one
-11,844 ???:<rustc_resolve::Resolver>::resolve_import::{closure
11,452 ???:core::ptr::drop_in_place::<rustc_ast::ast::PatKind>
-10,641 ???:<rustc_ast_lowering::LoweringContext>::lower_qpath
9,134 ???:<rustc_parse::parser::Parser>::collect_pos
-8,730 ./string/../sysdeps/x86_64/strcmp.S:strcmp
-8,407 ???:<rustc_resolve::build_reduced_graph::BuildReducedGraphVisitor as rustc_ast::visit::Visitor>::visit_assoc_item
-7,843 ???:<rustc_ast::tokenstream::TokenCursor as core::clone::Clone>::clone
6,438 ???:<rustc_ast_lowering::LoweringContext>::lower_expr_mut

[Mark-Simulacrum]

Indeed odd, but given that this change is plausibly helping future perf work (parallel compiler) and the regressions are relatively small in magnitude and limited to just a few benchmarks, I'm going to go ahead and mark this triaged.

It also looks possible this is just noise:

(I didn't check all of the diff graphs, but at least a few have the same pattern of this being a ~single commit regression).