view-types: store view types in the AST by scrabsha · Pull Request #156016 · rust-lang/rust

scrabsha · 2026-04-30T20:49:17Z

Tracking issue: #155938.

Instead of discarding view types, we store them in the AST now!

JonathanBrouwer · 2026-05-03T10:24:05Z

view-types: store borrows of view types in the AST

rust-bors · 2026-05-03T12:34:42Z

☀️ Try build successful (CI)
Build commit: 9d3dea7 (9d3dea74651f758e35177070e510be8f3639a7fd, parent: 6769f690f947f12e36db6b6503bab265b7b2cced)

rust-timer · 2026-05-03T13:17:31Z

Finished benchmarking commit (9d3dea7): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@bors rollup=never
@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
Improvements ✅ (primary)	-0.7%	[-1.4%, -0.3%]	6
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.1%]	2
All ❌✅ (primary)	-0.7%	[-1.4%, -0.3%]	6

Max RSS (memory usage)

Results (primary 0.1%, secondary -2.6%)

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

	mean	range	count
Regressions ❌ (primary)	1.9%	[1.9%, 1.9%]	1
Regressions ❌ (secondary)	1.2%	[1.2%, 1.2%]	1
Improvements ✅ (primary)	-0.8%	[-0.8%, -0.7%]	2
Improvements ✅ (secondary)	-4.4%	[-7.3%, -1.5%]	2
All ❌✅ (primary)	0.1%	[-0.8%, 1.9%]	3

Cycles

Results (secondary 3.4%)

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)	5.0%	[0.5%, 9.9%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.3%	[-1.3%, -1.3%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 503.61s -> 496.571s (-1.40%)
Artifact size: 394.46 MiB -> 394.47 MiB (0.00%)

scrabsha · 2026-05-03T16:11:34Z

^

rebased to main to fix conflicts
fixed view-types: store view types in the AST #156016 (comment)

r? nikomatsakis

oli-obk · 2026-07-06T14:53:58Z

rust-bors · 2026-07-06T14:54:01Z

📌 Commit dcdf133 has been approved by oli-obk

It is now in the queue for this repository.

view-types: store view types in the AST

rust-bors · 2026-07-07T08:25:42Z

⚠️ A new commit 3ed5f56b7d381af42cd7a460a777cd5ea500af85 was pushed.

This pull request was unapproved.

Auto build was cancelled due to push. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/28851160777

oli-obk · 2026-07-07T09:37:37Z

@bors r+

rust-bors · 2026-07-07T09:37:41Z

📌 Commit 3ed5f56 has been approved by oli-obk

It is now in the queue for this repository.

view-types: store view types in the AST

rust-bors · 2026-07-07T16:20:43Z

💔 Test for 75770e7 failed: CI. Failed job:

auto - aarch64-apple-macos-26 (web logs, enhanced plaintext logs)

rust-log-analyzer · 2026-07-07T16:20:51Z

The job aarch64-apple-macos-26 failed! Check out the build log: (web)(plain enhanced)(plain)

Click to see the possible cause of the failure (guessed by this bot)

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JonathanBrouwer · 2026-07-07T19:35:27Z

@bors retry

scrabsha · 2026-07-07T20:08:35Z

@JonathanBrouwer btw, this PR used to be rollup=never because we were not sure about its perf impact, but now it's reasonable to assume the perf is ok (the code has been reworked quite a lot since). would you be ok with rolluping it?

JonathanBrouwer · 2026-07-07T20:18:53Z

@bors rollup=iffy

…uwer Rollup of 19 pull requests Successful merges: - #156016 (view-types: store view types in the AST) - #157385 (Enable Enzyme on x86_64-apple) - #158179 (std: unconditionally use `preadv`/`pwritev` on AArch64 macOS) - #158621 (disallow `extern "custom"` on wasm and spirv targets) - #158690 (delegation: support mapping of all arguments with `Self` type) - #158696 (Rename some `body_id` to `body_def_id`) - #158697 (Fixes for QNX SDP 8) - #158760 (Clarify that `LocalKey::try_with` may return `AccessError`) - #157801 (Rewrite safety requirements for `Allocator` impls) - #158085 (rustdoc: Fix sidebar heading order) - #158333 (Fix typetree generation for differentiated functions) - #158646 (powerpc64le_unknown_freebsd.rs: link with -lgcc) - #158701 ( diagnostics: suggest type annotation for closure params on HRTB FnOnce mismatch) - #158791 (Avoid unused braces lint for macro generated arguments) - #158802 (Use `ci-mirrors` in `armhf-gnu` for {busybox, ubuntu rootfs} artifacts) - #158841 (Avoid final override ICE for RPITIT associated types) - #158889 (tests: catch up with LLVM returning f128 on the stack) - #158905 (delegation: add constraints to new generic args) - #158922 (tests: clean up over-constraint on LLVM feature count) Failed merges: - #158617 (allow mGCA const arguments to fall back to anon consts)

rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 30, 2026