`rustc_builtin_macros` cleanup, part 5 by cyrgani · Pull Request #163080 · rust-lang/rust

cyrgani · 2026-09-20T20:29:24Z

This PR among other things removes the "mini" version of Path, the nonselflike_args and most of the usages of type_ident. It also comes with some perf gains.
Followup to #162925.

r? @nnethercote

rustbot · 2026-09-20T20:29:27Z

Changes to the code generated for builtin derived traits.

cc @nnethercote

clarfonthey · 2026-09-20T22:34:32Z

@bors try @rust-timer queue

`rustc_builtin_macros` cleanup, part 5

rust-bors · 2026-09-20T23:39:23Z

☀️ Try build successful (CI)
Build commit: 7e9ca0a (7e9ca0a359bea11fd329d868a5e49ec7a11f447b)
Base parent: bba5310 (bba531001d4de6d7f49693e0836a2668ca063282)

rust-timer · 2026-09-21T00:23:11Z

Finished benchmarking commit (7e9ca0a): comparison URL.

Overall result: ❌✅ regressions and improvements - 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)	0.2%	[0.1%, 0.3%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-0.8%, -0.8%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 2.1%)

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

	mean	range	count
Regressions ❌ (primary)	2.1%	[2.1%, 2.1%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.1%	[2.1%, 2.1%]	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: 496.585s -> 495.879s (-0.14%)
Artifact size: 408.87 MiB -> 406.94 MiB (-0.47%)

nnethercote

Mostly looks good, just the one concern about an error message.

View changes since this review

cyrgani · 2026-09-21T12:51:01Z

                        .additional_bounds
                        .iter()
-                        .map(|p| cx.trait_bound(p.to_path(cx, span), self.is_const))
+                        .map(|p| cx.trait_bound(ast::Path { span, ..p.clone() }, self.is_const))


The diagnostic previously changed because I didn't notice that this span is not the same as self.span, and p was constructed with self.span.

View changes since the review

nnethercote · 2026-09-21T23:07:49Z

@bors r+

Do you have the removal of Ty on your todo list? I've always found it a strange type.

rust-bors · 2026-09-21T23:07:52Z

📌 Commit c2328bf has been approved by nnethercote

It is now in the queue for this repository.

Rollup of 4 pull requests Successful merges: - #163049 (Tweak dyn compatibility error when pointing at receiver) - #163051 (Make CovariantUnsafeCell actually covariant) - #163080 (`rustc_builtin_macros` cleanup, part 5) - #163100 (normalize normalizes, avoid next-solver hack)

@nnethercote

Rollup merge of #163080 - cyrgani:builtin-macros-5, r=nnethercote `rustc_builtin_macros` cleanup, part 5 This PR among other things removes the "mini" version of `Path`, the `nonselflike_args` and most of the usages of `type_ident`. It also comes with some perf gains. Followup to #162925. r? @nnethercote

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 Sep 20, 2026

rustbot assigned nnethercote Sep 20, 2026

rust-cloud-vms Bot force-pushed the builtin-macros-5 branch from 9fea3d2 to fdea084 Compare September 20, 2026 20:31