Some `GlobalCtxt`/`Session` cleanups by nnethercote · Pull Request #161332 · rust-lang/rust

nnethercote · 2026-08-18T22:37:47Z

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Details in individual commits.

r? @Zalathar

To `QuerySystem`, next to `query_vtables`. It's a better spot for it.

nnethercote · 2026-08-18T22:38:02Z

@bors try @rust-timer queue

Some `GlobalCtxt`/`Session` cleanups

rust-bors · 2026-08-18T23:37:06Z

☀️ Try build successful (CI)
Build commit: 269c121 (269c121db841542a1520014d2f5f8f5c306b93cb)
Base parent: e71c0f1 (e71c0f1e3395b10a8c331317be1a5c107bdf7b2e)

rust-timer · 2026-08-19T00:48:30Z

Finished benchmarking commit (269c121): comparison URL.

Overall result: ❌ regressions - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@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)	0.2%	[0.1%, 0.4%]	41
Regressions ❌ (secondary)	0.2%	[0.0%, 0.5%]	39
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[0.1%, 0.4%]	41

Max RSS (memory usage)

Results (primary 2.3%)

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

	mean	range	count
Regressions ❌ (primary)	2.3%	[2.3%, 2.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.3%	[2.3%, 2.3%]	1

Cycles

This perf run didn't have relevant results for this metric.

Binary size

Results (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
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	12
All ❌✅ (primary)	-	-	0

Bootstrap: 456.919s -> 458.093s (0.26%)
Artifact size: 398.99 MiB -> 399.07 MiB (0.02%)

nnethercote · 2026-08-19T02:13:42Z

Gee whiz, doing tcx.sess.prof instead of tcx.prof is a measurable slowdown. I'll take out that change.

nnethercote · 2026-08-19T02:14:48Z

@bors try @rust-timer queue

Some `GlobalCtxt`/`Session` cleanups

rust-bors · 2026-08-19T03:14:00Z

☀️ Try build successful (CI)
Build commit: aeb7e24 (aeb7e24b02316d91850f36e7fccf6501e06e92c3)
Base parent: e71c0f1 (e71c0f1e3395b10a8c331317be1a5c107bdf7b2e)

rust-timer · 2026-08-19T04:08:30Z

Finished benchmarking commit (aeb7e24): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary 1.8%, secondary -7.3%)

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

	mean	range	count
Regressions ❌ (primary)	1.8%	[1.8%, 1.8%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-7.3%	[-7.3%, -7.3%]	1
All ❌✅ (primary)	1.8%	[1.8%, 1.8%]	1

Cycles

This perf run didn't have relevant results for this metric.

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 456.919s -> 456.535s (-0.08%)
Artifact size: 398.99 MiB -> 399.00 MiB (0.00%)

rustbot · 2026-08-19T08:38:47Z

Zalathar is not on the review rotation at the moment.
They may take a while to respond.

nnethercote · 2026-08-19T08:39:31Z

LLM disclosure: the suggestions for these changes came from an LLM's analysis. I made all the code and text changes myself.

Zalathar · 2026-08-19T10:54:10Z

Yeah, these all look good.

r=me with or without my suggested comment.

This commit moves the eight cache fields in `GlobalCtxt` into a single type, just to provide some logical grouping and to reduce the number of fields within `GlobalCtxt`.

It makes sense next to `QuerySystem::side_effects`, and this enables the use of `DepNodeIndex` for the values instead of the type-erased `u32`.

nnethercote · 2026-08-19T11:24:42Z

@bors r=Zalathar

rust-bors · 2026-08-19T11:24:45Z

📌 Commit c55f5a3 has been approved by Zalathar

It is now in the queue for this repository.

Zalathar · 2026-08-19T13:00:39Z

Perf ended up neutral after backing out the regressions.

@bors rollup=maybe

@Zalathar

…anups, r=Zalathar Some `GlobalCtxt`/`Session` cleanups Details in individual commits. r? @Zalathar

…uwer Rollup of 16 pull requests Successful merges: - #159071 ([PAC] Encoder and hash (1/8)) - #161277 (bootstrap: Move all non-module items out of the crate root) - #161332 (Some `GlobalCtxt`/`Session` cleanups) - #161344 (Update the `rustc-perf` submodule) - #150931 (rustdoc: Always document `#[repr(transparent)]` if `#[rustc_pub_transparent]` is applied) - #160582 (Add `remove hidden_glob_reexports item breaks downstream` test) - #160876 (remove unwrap from write_mir_fn_graphviz) - #160927 (Enhance EII UI tests) - #161070 (fix arm homogeneous aggregate ABI) - #161236 (Download auto jobs in citool in parallel) - #161254 (Reserve capacity for 3% anon nodes) - #161283 (Tighten the language used for documenting `TargetOptions::llvm_abiname`) - #161291 (Rename `ProjectionPredicate` and `TraitPredicate`) - #161299 (Remove a bunch of unnecessary explicit lifetimes) - #161307 (make ARM maintainers pingable) - #161308 (Add regression test for rustc diagnostic to recognize variables in match guards)

@Zalathar

…anups, r=Zalathar Some `GlobalCtxt`/`Session` cleanups Details in individual commits. r? @Zalathar

…uwer Rollup of 16 pull requests Successful merges: - #159071 ([PAC] Encoder and hash (1/8)) - #161068 (Ensure TLS accesses don't call the global allocator through panic (part 3) ) - #161332 (Some `GlobalCtxt`/`Session` cleanups) - #161344 (Update the `rustc-perf` submodule) - #150931 (rustdoc: Always document `#[repr(transparent)]` if `#[rustc_pub_transparent]` is applied) - #160582 (Add `remove hidden_glob_reexports item breaks downstream` test) - #160876 (remove unwrap from write_mir_fn_graphviz) - #160927 (Enhance EII UI tests) - #161070 (fix arm homogeneous aggregate ABI) - #161236 (Download auto jobs in citool in parallel) - #161254 (Reserve capacity for 3% anon nodes) - #161283 (Tighten the language used for documenting `TargetOptions::llvm_abiname`) - #161291 (Rename `ProjectionPredicate` and `TraitPredicate`) - #161299 (Remove a bunch of unnecessary explicit lifetimes) - #161307 (make ARM maintainers pingable) - #161308 (Add regression test for rustc diagnostic to recognize variables in match guards)

@Zalathar

…anups, r=Zalathar Some `GlobalCtxt`/`Session` cleanups Details in individual commits. r? @Zalathar

Move GlobalCtxt::dep_kind_vtables

a63c33b

To `QuerySystem`, next to `query_vtables`. It's a better spot for it.