Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type #140453

Zoxc · 2025-04-29T12:14:22Z

This removes Definitions.next_disambiguator as it doesn't guarantee deterministic def paths when create_def is called in parallel. Instead a new DisambiguatorState type is passed as a mutable reference to create_def to help create unique def paths. create_def calls with distinct DisambiguatorState instances must ensure that that the def paths are unique without its help.

Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the DefPathData to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer.

DefPathData::NestedStatic is added to use for nested data inside statics instead of reusing DefPathData::AnonConst to avoid conflicts with those.

cc @oli-obk

…iguatorState` type

rustbot · 2025-04-29T12:14:26Z

r? @estebank

rustbot has assigned @estebank.
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

rustbot · 2025-04-29T12:14:28Z

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in compiler/rustc_sanitizers

cc @rcvalle

compiler/rustc_const_eval/src/const_eval/machine.rs

petrochenkov · 2025-04-29T12:52:05Z

compiler/rustc_hir/src/definitions.rs

+
+impl DisambiguatorState {
+    pub fn new() -> Self {
+        Self { next: Default::default() }


#[derive(Default)] can be used instead of this.

I do prefer new if Default isn't needed though.

compiler/rustc_hir/src/definitions.rs

compiler/rustc_middle/src/ty/context.rs

compiler/rustc_mir_transform/src/coroutine/by_move_body.rs

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

…Const`

compiler/rustc_const_eval/src/interpret/intern.rs

oli-obk · 2025-05-04T18:13:26Z

@bors try @rust-timer queue

bors · 2025-05-04T18:14:38Z

⌛ Trying commit acb50d5 with merge 1febaad...

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type This removes `Definitions.next_disambiguator` as it doesn't guarantee deterministic def paths when `create_def` is called in parallel. Instead a new `DisambiguatorState` type is passed as a mutable reference to `create_def` to help create unique def paths. `create_def` calls with distinct `DisambiguatorState` instances must ensure that that the def paths are unique without its help. Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the `DefPathData` to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer. `DefPathData::NestedStatic` is added to use for nested data inside statics instead of reusing `DefPathData::AnonConst` to avoid conflicts with those. cc `@oli-obk`

bors · 2025-05-04T20:23:42Z

☀️ Try build successful - checks-actions
Build commit: 1febaad (1febaad87593af7579d4d2dc363e8854d2d6e0fb)

rust-timer · 2025-05-04T23:15:47Z

Finished benchmarking commit (1febaad): comparison URL.

Overall result: no relevant changes - no 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.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary 0.2%, secondary 1.9%)

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)	0.7%	[0.4%, 1.4%]	12
Regressions ❌ (secondary)	1.9%	[1.9%, 1.9%]	1
Improvements ✅ (primary)	-0.6%	[-0.9%, -0.4%]	6
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-0.9%, 1.4%]	18

Cycles

Results (primary -0.3%)

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)	0.6%	[0.4%, 1.1%]	6
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.2%, -0.4%]	18
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.3%	[-1.2%, 1.1%]	24

Binary size

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

Bootstrap: 770.413s -> 770.195s (-0.03%)
Artifact size: 365.46 MiB -> 365.34 MiB (-0.03%)

oli-obk · 2025-05-05T09:07:47Z

@bors r+

bors · 2025-05-05T09:07:50Z

📌 Commit acb50d5 has been approved by oli-obk

It is now in the queue for this repository.

bors · 2025-05-05T11:50:47Z

⌛ Testing commit acb50d5 with merge 243c5a3...

bors · 2025-05-05T14:58:54Z

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 243c5a3 to master...

github-actions · 2025-05-05T15:01:06Z

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 0eb0b8c (parent) -> 243c5a3 (this PR)

Test differences

Show 20 test diffs

20 doctest diffs were found. These are ignored, as they are noisy.

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 243c5a35e18b2634892fe7091d5ee888a18f77f5 --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

x86_64-apple-1: 6425.5s -> 9397.1s (46.2%)
aarch64-apple: 3642.7s -> 4591.7s (26.1%)
dist-apple-various: 6382.7s -> 7696.3s (20.6%)
dist-x86_64-apple: 10259.5s -> 9063.0s (-11.7%)
x86_64-msvc-ext2: 5740.7s -> 6314.5s (10.0%)
x86_64-msvc-ext1: 7141.8s -> 7759.9s (8.7%)
x86_64-msvc-2: 6636.0s -> 7207.2s (8.6%)
dist-arm-linux: 4992.4s -> 4577.4s (-8.3%)
x86_64-apple-2: 5604.6s -> 5147.1s (-8.2%)
dist-powerpc-linux: 5288.0s -> 5681.2s (7.4%)

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 · 2025-05-05T16:34:49Z

Finished benchmarking commit (243c5a3): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-0.7%, -0.7%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.7%	[-0.7%, -0.7%]	1

Max RSS (memory usage)

Results (primary 0.7%, secondary -2.5%)

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)	1.2%	[0.4%, 2.5%]	11
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.1%	[-1.8%, -0.5%]	3
Improvements ✅ (secondary)	-2.5%	[-2.6%, -2.4%]	2
All ❌✅ (primary)	0.7%	[-1.8%, 2.5%]	14

Cycles

Results (primary 0.2%, secondary 2.2%)

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)	0.5%	[0.4%, 0.6%]	16
Regressions ❌ (secondary)	2.2%	[1.5%, 2.9%]	2
Improvements ✅ (primary)	-1.2%	[-2.4%, -0.5%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-2.4%, 0.6%]	20

Binary size

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

Bootstrap: 768.8s -> 770.492s (0.22%)
Artifact size: 365.42 MiB -> 365.47 MiB (0.01%)

Zoxc · 2025-05-07T13:35:03Z

Looks like my assumption in resolve_bound_vars was incorrect and lifetimes inside opaque nodes can appear when lowering to HIR, which causes #140731.

I'm not quite sure what the purpose of the remapped lifetime def paths are, but perhaps these should be synthetic to avoid conflicts as they do look like some form of desugaring. cc @cjgillot

Another fix could be to pass on DisambiguatorState from lowering, but cloning that could be expensive.

oli-obk · 2025-05-07T15:31:02Z

but cloning that could be expensive.

why would it be cloned?

But yea, just giving them a unique DefPathData should be simpler

oli-obk and others added 2 commits April 28, 2025 18:11

We always use the current item as parent, so no need to pass it

2ac60bc

Remove global next_disambiguator state and handle it with a `Disamb…

e561ec0

…iguatorState` type

rustbot assigned estebank Apr 29, 2025

rustbot added PG-exploit-mitigations Project group: Exploit mitigations S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 29, 2025

This comment has been minimized.

Sign in to view

petrochenkov self-assigned this Apr 29, 2025

Update stable-mir test

df1f8d1

RalfJung reviewed Apr 29, 2025

View reviewed changes

compiler/rustc_const_eval/src/const_eval/machine.rs Outdated Show resolved Hide resolved

oli-obk assigned oli-obk and unassigned estebank Apr 29, 2025

petrochenkov reviewed Apr 29, 2025

View reviewed changes

petrochenkov removed their assignment Apr 29, 2025

Zoxc added 4 commits May 2, 2025 12:24

Rename parameter to override_def_path_data

ddff387

Add DefPathData::NestedStatic instead of reusing `DefPathData::Anon…

efc51ce

…Const`

Add comment about the symbol on AnonAssocTy

d16daf5

Split get_opt_name hashing use into hashed_symbol

4869e20

oli-obk reviewed May 2, 2025

View reviewed changes

compiler/rustc_const_eval/src/interpret/intern.rs Outdated Show resolved Hide resolved

oli-obk removed the PG-exploit-mitigations Project group: Exploit mitigations label May 2, 2025

Move DisambiguatorState into intern_const_alloc_recursive

6a48217

Zoxc force-pushed the next-disambiguator branch from d5a3b9c to 6a48217 Compare May 2, 2025 13:51

rustbot added the PG-exploit-mitigations Project group: Exploit mitigations label May 2, 2025

oli-obk added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels May 2, 2025

RalfJung reviewed May 2, 2025

View reviewed changes

compiler/rustc_const_eval/src/interpret/intern.rs Show resolved Hide resolved

Zoxc added 2 commits May 4, 2025 19:14

Add comment on creation of SyntheticCoroutineBody

9f8c6d5

Add comment on creation of lifetime inside opaque types

acb50d5

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label May 4, 2025

This comment has been minimized.

Sign in to view

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label May 4, 2025

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels May 5, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label May 5, 2025

bors merged commit 243c5a3 into rust-lang:master May 5, 2025
7 checks passed

rustbot added this to the 1.88.0 milestone May 5, 2025

Zoxc deleted the next-disambiguator branch May 5, 2025 15:15

matthiaskrgr mentioned this pull request May 7, 2025

ICE / Hang found DefPathHash collision between DefPath #140731

Closed

moxian mentioned this pull request May 8, 2025

ICE / Hang found DefPathHash collision between DefPath #140796

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type #140453

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type #140453

Zoxc commented Apr 29, 2025 •

edited

Loading

rustbot commented Apr 29, 2025

rustbot commented Apr 29, 2025

This comment has been minimized.

petrochenkov Apr 29, 2025

Zoxc May 4, 2025

oli-obk commented May 4, 2025

This comment has been minimized.

bors commented May 4, 2025

bors commented May 4, 2025

This comment has been minimized.

rust-timer commented May 4, 2025

oli-obk commented May 5, 2025

bors commented May 5, 2025

bors commented May 5, 2025

bors commented May 5, 2025

github-actions bot commented May 5, 2025

rust-timer commented May 5, 2025

Zoxc commented May 7, 2025

oli-obk commented May 7, 2025

Remove global next_disambiguator state and handle it with a DisambiguatorState type #140453

Remove global next_disambiguator state and handle it with a DisambiguatorState type #140453

Conversation

Zoxc commented Apr 29, 2025 • edited Loading

rustbot commented Apr 29, 2025

rustbot commented Apr 29, 2025

This comment has been minimized.

Choose a reason for hiding this comment

Choose a reason for hiding this comment

oli-obk commented May 4, 2025

This comment has been minimized.

bors commented May 4, 2025

bors commented May 4, 2025

This comment has been minimized.

rust-timer commented May 4, 2025

Overall result: no relevant changes - no action needed

oli-obk commented May 5, 2025

bors commented May 5, 2025

bors commented May 5, 2025

bors commented May 5, 2025

github-actions bot commented May 5, 2025

Test differences

Job duration changes

rust-timer commented May 5, 2025

Overall result: ✅ improvements - no action needed

Zoxc commented May 7, 2025

oli-obk commented May 7, 2025

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type #140453

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type #140453

Zoxc commented Apr 29, 2025 •

edited

Loading