Remove rustc_middle dependency on rustc_hir_pretty by mejrs · Pull Request #160360 · rust-lang/rust

mejrs · 2026-08-01T23:36:01Z

There is a impl PpAnn for TyCtxt that is unneeded. None of the big crates (middle, trait_selection) actually do any hir pretty printing so it can be removed and can either be implemented for local structs elsewhere or done by casting to &dyn PpAnn instead.

This probably doesn't have any perf effects (its not bottlenecking in timings) but I expect it to compose with #160336 and its followup works quite well.

Old graph:

New graph:

rustbot · 2026-08-01T23:36:04Z

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

rustbot · 2026-08-01T23:36:07Z

r? @nnethercote

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mejrs · 2026-08-01T23:40:14Z

+impl<'tcx, B: Bridge> rustc_hir_pretty::PpAnn for CompilerCtxt<'tcx, B> {
+    fn nested(&self, state: &mut rustc_hir_pretty::State<'_>, nested: rustc_hir_pretty::Nested) {
+        rustc_hir_pretty::PpAnn::nested(
+            &(&self.tcx as &dyn rustc_hir::intravisit::HirTyCtxt<'_>),
+            state,
+            nested,
+        )
+    }
+}
+


@celinval / @makai410 I'm low on rustc_public context and don't know if this impl can leak to rustc_public. This impl can be removed and replaced by a cast at the callsites, at your option.

View changes since the review

mejrs · 2026-08-01T23:41:21Z

@bors try @rust-timer queue

Remove rustc_middle dependency on rustc_hir_pretty

mejrs · 2026-08-02T00:05:18Z

@bors try cancel

rust-bors · 2026-08-02T00:05:22Z

Try build cancelled. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/30723816470

rustbot · 2026-08-02T00:22:17Z

clippy is developed in its own repository. If possible, consider making this change to rust-lang/rust-clippy instead.

cc @rust-lang/clippy

mejrs · 2026-08-02T00:23:12Z

@bors try @rust-timer queue

Remove rustc_middle dependency on rustc_hir_pretty

rust-bors · 2026-08-02T02:28:53Z

☀️ Try build successful (CI)
Build commit: 0f4b3c5 (0f4b3c574fc058404e9860030574806f0a9564f0)
Base parent: 73dc916 (73dc9167f1cd099e525c9ade2e068d1907b78564)

rust-timer · 2026-08-02T03:53:28Z

Finished benchmarking commit (0f4b3c5): comparison URL.

Overall result: ❌ regressions - 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

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

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.3%	[0.2%, 0.5%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 0.5%, secondary 0.4%)

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

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.5%, 0.5%]	1
Regressions ❌ (secondary)	0.6%	[0.4%, 0.6%]	8
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.6%	[-0.6%, -0.6%]	1
All ❌✅ (primary)	0.5%	[0.5%, 0.5%]	1

Cycles

Results (primary 0.0%, secondary -0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.4%, 2.3%]	7
Regressions ❌ (secondary)	0.8%	[0.4%, 2.5%]	6
Improvements ✅ (primary)	-2.1%	[-3.6%, -1.2%]	3
Improvements ✅ (secondary)	-1.5%	[-3.7%, -0.5%]	4
All ❌✅ (primary)	0.0%	[-3.6%, 2.3%]	10

Binary size

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

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)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.1%, -0.0%]	63
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.0%]	57
All ❌✅ (primary)	-0.1%	[-0.1%, -0.0%]	63

Bootstrap: 490.553s -> 490.894s (0.07%)
Artifact size: 390.33 MiB -> 390.29 MiB (-0.01%)

nnethercote

Nice to untangle rustc_middle a tiny bit. r=me after considering the nit.

View changes since this review

nnethercote · 2026-08-02T22:07:44Z

 impl<'tcx> pprust_hir::PpAnn for HirIdentifiedAnn<'tcx> {
    fn nested(&self, state: &mut pprust_hir::State<'_>, nested: pprust_hir::Nested) {
-        self.tcx.nested(state, nested)
+        let slf = &self.tcx as &dyn intravisit::HirTyCtxt<'_>;


I'm more used to this being the alternative to self.

Or self_.

There is a `impl PpAnn for TyCtxt` that is unneeded. None of the big crates (middle, trait_selection) actually do any hir pretty printing so it can be removed and can either be implemented for local structs elsewhere or done by casting to `&dyn PpAnn` instead.

rustbot · 2026-08-04T17:04:55Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

nnethercote · 2026-08-04T21:34:08Z

@bors r+

rust-bors · 2026-08-04T21:34:11Z

📌 Commit 180c637 has been approved by nnethercote

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 10. This pull request will be tested once the tree is reopened.

Reason for tree closure: manually handling queue due to backlog

Remove rustc_middle dependency on rustc_hir_pretty There is a `impl PpAnn for TyCtxt` that is unneeded. None of the big crates (middle, trait_selection) actually do any hir pretty printing so it can be removed and can either be implemented for local structs elsewhere or done by casting to `&dyn PpAnn` instead. This probably doesn't have any perf effects (its not bottlenecking in timings) but I expect it to compose with rust-lang#160336 and its followup works quite well. Old graph: <img width="1999" height="2171" alt="graph" src="https://github.com/user-attachments/assets/756e6a50-a413-4a8d-a0f3-7bbf4de07933" /> New graph: <img width="1853" height="2171" alt="graph_hir_pretty" src="https://github.com/user-attachments/assets/f9607e5a-d00b-4a86-8f6a-cefb45b75ad7" />

…uwer Rollup of 22 pull requests Successful merges: - #158147 (std: fix stack buffer overflow in Windows junction_point) - #159784 (Hint that memchr returns an in-bounds index) - #160130 (Select cache values to verify by key fingerprint, not value fingerprint) - #160343 (Rename `OutlivesPredicate` to `OutlivesClause`) - #160360 (Remove rustc_middle dependency on rustc_hir_pretty) - #160387 (rustc_codegen_ssa: Correctly apply the static `--jobs-backend` limit to backend parallelism) - #160422 (move mir-opt miri tests to CI logic) - #160444 (Avoid resolving path keywords outside `TypeNS`) - #160510 (Resolver: (un)tracked borrows for `CmRefCell` made safe my unsafe speculative flag) - #155424 ([blocked] Link to proposed LLM policy in CONTRIBUTING and pull request template) - #158726 (std: move futex implementations into sys::sync::futex) - #159225 (Split IncrCompSession out of Session) - #159820 (Make the `rustc_unsafe_specialization_marker` attribute actually `unsafe`) - #160198 (Rework `smallest_range_containing` to handle duplicates) - #160362 (Split `SpannedTypeVisitor` into its own crate, `rustc_ty_walk`) - #160390 (autodiff: Handle slice-tailed DSTs in type trees) - #160420 (Suggest `cast_signed()` for overflowing signed integer literals) - #160520 (Add some tests for specialization) - #160522 (fix(bootstrap): Normalize the names of proc macro dependency crates) - #160531 (docs: fix typo in AllowExprMetavar comment) - #160538 (Update expect messages in tcp.rs doc examples to follow the style guide) - #160548 (bootstrap: Register `coverage-map` and `coverage-run` aliases via a separate step)

Remove rustc_middle dependency on rustc_hir_pretty There is a `impl PpAnn for TyCtxt` that is unneeded. None of the big crates (middle, trait_selection) actually do any hir pretty printing so it can be removed and can either be implemented for local structs elsewhere or done by casting to `&dyn PpAnn` instead. This probably doesn't have any perf effects (its not bottlenecking in timings) but I expect it to compose with rust-lang#160336 and its followup works quite well. Old graph: <img width="1999" height="2171" alt="graph" src="https://github.com/user-attachments/assets/756e6a50-a413-4a8d-a0f3-7bbf4de07933" /> New graph: <img width="1853" height="2171" alt="graph_hir_pretty" src="https://github.com/user-attachments/assets/f9607e5a-d00b-4a86-8f6a-cefb45b75ad7" />

…uwer Rollup of 25 pull requests Successful merges: - #154585 (treat no_mangle_generic_items as hard error instead of lint warning) - #158147 (std: fix stack buffer overflow in Windows junction_point) - #160130 (Select cache values to verify by key fingerprint, not value fingerprint) - #160343 (Rename `OutlivesPredicate` to `OutlivesClause`) - #160360 (Remove rustc_middle dependency on rustc_hir_pretty) - #160387 (rustc_codegen_ssa: Correctly apply the static `--jobs-backend` limit to backend parallelism) - #160422 (move mir-opt miri tests to CI logic) - #160444 (Avoid resolving path keywords outside `TypeNS`) - #160510 (Resolver: (un)tracked borrows for `CmRefCell` made safe my unsafe speculative flag) - #155424 ([blocked] Link to proposed LLM policy in CONTRIBUTING and pull request template) - #158726 (std: move futex implementations into sys::sync::futex) - #158762 (Emit thumb code on VEX V5) - #159225 (Split IncrCompSession out of Session) - #159820 (Make the `rustc_unsafe_specialization_marker` attribute actually `unsafe`) - #160198 (Rework `smallest_range_containing` to handle duplicates) - #160362 (Split `SpannedTypeVisitor` into its own crate, `rustc_ty_walk`) - #160390 (autodiff: Handle slice-tailed DSTs in type trees) - #160420 (Suggest `cast_signed()` for overflowing signed integer literals) - #160516 (Add regression test for HRTB projection in closure) - #160520 (Add some tests for specialization) - #160522 (fix(bootstrap): Normalize the names of proc macro dependency crates) - #160523 (Add regression test for opaque type) - #160531 (docs: fix typo in AllowExprMetavar comment) - #160538 (Update expect messages in tcp.rs doc examples to follow the style guide) - #160548 (bootstrap: Register `coverage-map` and `coverage-run` aliases via a separate step)

…uwer Rollup of 25 pull requests Successful merges: - #158147 (std: fix stack buffer overflow in Windows junction_point) - #160130 (Select cache values to verify by key fingerprint, not value fingerprint) - #160343 (Rename `OutlivesPredicate` to `OutlivesClause`) - #160360 (Remove rustc_middle dependency on rustc_hir_pretty) - #160387 (rustc_codegen_ssa: Correctly apply the static `--jobs-backend` limit to backend parallelism) - #160422 (move mir-opt miri tests to CI logic) - #160444 (Avoid resolving path keywords outside `TypeNS`) - #160510 (Resolver: (un)tracked borrows for `CmRefCell` made safe by unsafe speculative flag) - #155424 ([blocked] Link to proposed LLM policy in CONTRIBUTING and pull request template) - #158726 (std: move futex implementations into sys::sync::futex) - #158762 (Emit thumb code on VEX V5) - #159225 (Split IncrCompSession out of Session) - #159820 (Make the `rustc_unsafe_specialization_marker` attribute actually `unsafe`) - #160198 (Rework `smallest_range_containing` to handle duplicates) - #160362 (Split `SpannedTypeVisitor` into its own crate, `rustc_ty_walk`) - #160390 (autodiff: Handle slice-tailed DSTs in type trees) - #160420 (Suggest `cast_signed()` for overflowing signed integer literals) - #160501 (Add bootstrap CLI snapshot test for testing miri) - #160516 (Add regression test for HRTB projection in closure) - #160520 (Add some tests for specialization) - #160522 (fix(bootstrap): Normalize the names of proc macro dependency crates) - #160523 (Add regression test for opaque type) - #160531 (docs: fix typo in AllowExprMetavar comment) - #160538 (Update expect messages in tcp.rs doc examples to follow the style guide) - #160548 (bootstrap: Register `coverage-map` and `coverage-run` aliases via a separate step)

Rollup merge of #160360 - mejrs:hir_pretty, r=nnethercote Remove rustc_middle dependency on rustc_hir_pretty There is a `impl PpAnn for TyCtxt` that is unneeded. None of the big crates (middle, trait_selection) actually do any hir pretty printing so it can be removed and can either be implemented for local structs elsewhere or done by casting to `&dyn PpAnn` instead. This probably doesn't have any perf effects (its not bottlenecking in timings) but I expect it to compose with #160336 and its followup works quite well. Old graph: <img width="1999" height="2171" alt="graph" src="https://github.com/user-attachments/assets/756e6a50-a413-4a8d-a0f3-7bbf4de07933" /> New graph: <img width="1853" height="2171" alt="graph_hir_pretty" src="https://github.com/user-attachments/assets/f9607e5a-d00b-4a86-8f6a-cefb45b75ad7" />

rustbot added 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 Aug 1, 2026

rustbot assigned nnethercote Aug 1, 2026

mejrs commented Aug 1, 2026

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