Rename `lazy_type_alias` feature gate to `checked_type_aliases` by josetorrs · Pull Request #158758 · rust-lang/rust

josetorrs · 2026-07-04T02:37:36Z

there's not an open issue for it, though happy to create one if desired, but this is the zulip thread. basically just did a cmd+shift+F on VSCode

r? @lcnr

cc: @BoxyUwU

josetorrs · 2026-07-04T02:44:40Z

+#![feature(checked_free_type_aliases)]



for these, the directory is tests/ui/lazy-type-alias/... but I wasn't sure if I should rename this TBH
View changes since the review

Ideally, yes, since I named this directory after the feature name. It currently exercises both the "checkedness" and the "laziness" ("retainedness") of LTA.

rustbot · 2026-07-04T03:13:44Z

HIR ty lowering was modified

cc @fmease

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

cc @BoxyUwU, @tshepang

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

cc @rust-lang/rust-analyzer

This PR changes a file inside tests/crashes. If a crash was fixed, please move into the corresponding ui subdir and add 'Fixes #' to the PR description to autoclose the issue upon merge.

fmease · 2026-07-04T07:34:57Z

 let ty = tcx.type_of(def_id).instantiate_identity();
 let span = tcx.def_span(def_id);
- if tcx.type_alias_is_lazy(def_id) {
+ if tcx.type_alias_is_free(def_id) {


All type aliases are free, that's their very nature. This function is returning (1) whether to check the type alias for well-formedness (2) whether to lower its use sites to an alias type instead of eagerly expanding them to the aliased type during HIR ty lowering.
This should probably say type_alias_is_checked.
If I split this feature into unchecked & checked in the future I guess I need to come up with a new way of expressing eager vs. lazy, maybe unretained vs. retained 🤔
View changes since the review

fmease · 2026-07-04T08:18:44Z

 }
 self.check_type_no_bounds(bounds, "this context");

- if self.features.lazy_type_alias() {


(Personally speaking, I'm voting for checked_type_aliases, cc #t-types/lazy-type-alias > name bikeshed @ 💬)
View changes since the review

let's wait ~2-3 days on https://rust-lang.zulipchat.com/#narrow/channel/609192-t-types.2Flazy-type-alias/topic/name.20bikeshed/near/608438367

the poll is unanimous with renaming to checked_type_alias. I think I should be good with changing it along with renaming the test directory per #158758 (comment) to tests/ui/checked-type-alias/... (?) and this rename
I didn't vote in the poll as I didn't want to pretend I 100% fully understood everything haha

fmease · 2026-07-04T08:20:59Z

+#![feature(checked_free_type_aliases)]



Ideally, yes, since I named this directory after the feature name. It currently exercises both the "checkedness" and the "laziness" ("retainedness") of LTA.

ChayimFriedman2 · 2026-07-04T17:40:26Z

 deny_since: None,
 },
 Lint {
- label: "lazy_type_alias",


Please do not change this file. It is auto-generated.
View changes since the review

Could you please remove the changes to this file completely, e.g., by interactive rebase-editing the commit 49c4377 or squashing commits rather than adding another commit undoing it?
We do sync this repository with rust-lang/rust-analyzer bidirectionally and the cleaner history helps it being done automatically without hassle 😄

rustbot · 2026-07-04T17:40:34Z

Reminder, once the PR becomes ready for a review, use @rustbot ready.

josetorrs · 2026-07-15T15:53:00Z

@bors r=lcnr

rust-bors · 2026-07-15T15:53:04Z

@josetorrs: 🔑 Insufficient privileges: not in review users

josetorrs · 2026-07-15T15:54:21Z

r=me after minor issue

@lcnr ah I don't have bors privileges. (though tbh not too familiar with bors)

lcnr · 2026-07-16T12:02:13Z

@bors r+ rollup=iffy (touches lots of files)

rust-bors · 2026-07-16T12:02:17Z

📌 Commit 526787d has been approved by lcnr

It is now in the queue for this repository.

@lcnr

…r=lcnr Rename `lazy_type_alias` feature gate to `checked_type_aliases` there's not an open issue for it, though happy to create one if desired, but [this](https://rust-lang.zulipchat.com/#narrow/channel/144729-t-types/topic/ask.20for.20help.3A.20rename.20.60lazy_type_alias.60.20feature/near/608089932) is the zulip thread. basically just did a cmd+shift+F on VSCode r? @lcnr cc: @BoxyUwU

@lcnr

…r=lcnr Rename `lazy_type_alias` feature gate to `checked_type_aliases` there's not an open issue for it, though happy to create one if desired, but [this](https://rust-lang.zulipchat.com/#narrow/channel/144729-t-types/topic/ask.20for.20help.3A.20rename.20.60lazy_type_alias.60.20feature/near/608089932) is the zulip thread. basically just did a cmd+shift+F on VSCode r? @lcnr cc: @BoxyUwU

…uwer Rollup of 18 pull requests Successful merges: - #150679 (dirfd file operations (2/4)) - #158758 (Rename `lazy_type_alias` feature gate to `checked_type_aliases` ) - #159177 (Explicitly materialize debuginfo tests for all debuggers) - #159392 (Update Rust crate rand to v0.9.3 [SECURITY]) - #159393 (Update Rust crate rkyv to v0.8.16 [SECURITY]) - #159394 (Update Rust crate tar to v0.4.46 [SECURITY]) - #159395 (Update Rust crate tracing-subscriber [SECURITY]) - #159193 (Port compiletest's CLI to clap) - #158992 (Shorten types more when only interesting part is lifetimes) - #159226 (Track extra_lifetime_params_map per-owner) - #159273 (tidy: document u64 limit for numeric sort keys) - #159322 (Fix safety doc in intrinsics::simd) - #159329 (Fix the stale metrics directory warning) - #159357 (Add regression tests for two fixed issues) - #159360 (Remove FIXMEs referencing #44232) - #159375 (make a couple codegen-llvm tests compatible with 2021 edition) - #159381 (emit `(lldb)` prefix to make commands more distinct) - #159396 (Update actions/checkout action to v7)

…uwer Rollup of 18 pull requests Successful merges: - rust-lang/rust#150679 (dirfd file operations (2/4)) - rust-lang/rust#158758 (Rename `lazy_type_alias` feature gate to `checked_type_aliases` ) - rust-lang/rust#159177 (Explicitly materialize debuginfo tests for all debuggers) - rust-lang/rust#159392 (Update Rust crate rand to v0.9.3 [SECURITY]) - rust-lang/rust#159393 (Update Rust crate rkyv to v0.8.16 [SECURITY]) - rust-lang/rust#159394 (Update Rust crate tar to v0.4.46 [SECURITY]) - rust-lang/rust#159395 (Update Rust crate tracing-subscriber [SECURITY]) - rust-lang/rust#159193 (Port compiletest's CLI to clap) - rust-lang/rust#158992 (Shorten types more when only interesting part is lifetimes) - rust-lang/rust#159226 (Track extra_lifetime_params_map per-owner) - rust-lang/rust#159273 (tidy: document u64 limit for numeric sort keys) - rust-lang/rust#159322 (Fix safety doc in intrinsics::simd) - rust-lang/rust#159329 (Fix the stale metrics directory warning) - rust-lang/rust#159357 (Add regression tests for two fixed issues) - rust-lang/rust#159360 (Remove FIXMEs referencing rust-lang/rust#44232) - rust-lang/rust#159375 (make a couple codegen-llvm tests compatible with 2021 edition) - rust-lang/rust#159381 (emit `(lldb)` prefix to make commands more distinct) - rust-lang/rust#159396 (Update actions/checkout action to v7)

rust-lang/rust#158758 renamed the `lazy_type_alias` nightly feature gate to `checked_type_aliases`; nightlies from ≈2026-07-19 on reject the old name with E0557, which breaks `nightly_generic_alias` builds on any current nightly. One-word change in the lib.rs cfg_attr. Requires a post-rename nightly (older ones don't know the new name, E0635) — martin's rust-toolchain.toml pin moves in lockstep (nightly-2026-07-30). Upstream will need the same fix.

The 3-month-old pin was due; done deliberately + fully re-verified per the rust-toolchain.toml policy, well before the Evoke deadline. Two things the newer nightly forced, both small: - rust-lang/rust#158758 RENAMED the `lazy_type_alias` feature gate to `checked_type_aliases`, so bevy_gaussian_splatting's `nightly_generic_alias` feature failed E0557 on any post-rename nightly. Fixed in the fork (martin-tightcut §11, one word in lib.rs); the git rev pin moves 608c7d1 → f94855a. Upstream will need the same fix. - New clippy lint `chunks_exact_to_as_chunks`: 4 sites (stereo→mono averaging in audio/analyze.rs, triangle-index walks in mesh.rs + scene/gl_dissolve.rs) now use `as_chunks::<N>()` — same shape, and the compiler gets constant-size chunks. Docs: DESIGN.md / Cargo.toml fork comments §1–10 → §1–11, OPTIMIZATION-BACKLOG.md pinned-rev note. Verified on nightly-2026-07-30: build --release (sh0 AND sh3), fmt --check, clippy -D warnings, 176 tests, reuse lint, `martin --validate`. Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

* fix: rename feature gate lazy_type_alias -> checked_type_aliases rust-lang/rust#158758 renamed the `lazy_type_alias` nightly feature gate to `checked_type_aliases`; nightlies from ~2026-07-19 on reject the old name with E0557 ("feature has been removed ... renamed"), which breaks every build with the `nightly_generic_alias` feature (on by default). Note this flips the nightly floor: the new name is unknown to pre-rename nightlies (E0635), so `nightly_generic_alias` now requires a nightly from ~2026-07-19 or later. Verified with `cargo check` on nightly-2026-07-30. * ci: bump RUST_TOOLCHAIN to nightly-2026-07-30 + fix new clippy lints The gate rename requires a post-2026-07-19 nightly, so move the CI pin from nightly-2026-06-20 to nightly-2026-07-30 (build/clippy/test/ deploy-pages workflows). That nightly's clippy adds `chunks_exact_to_as_chunks`; -D warnings hits four sites (raycast triangle walk, thumbnail-tool pixel loops, the visibility-render test) — converted to `as_chunks::<N>()`, same shape. Verified locally on nightly-2026-07-30: - cargo clippy --all-features --all-targets -- -D warnings - cargo fmt --all --check - cargo test (default) and --no-default-features --features "web io_ply tooling" - cargo check --no-default-features --features web --target wasm32-unknown-unknown

Bumps the pinned toolchain from nightly-2026-02-10 to nightly-2026-08-09 (rustc 1.99.0-nightly, 771916f90) and fixes the resulting breakage. `u32::widening_mul` now returns the full u64 product instead of a (low, high) tuple, so the `.1` in both mulhu implementations no longer compiles. mulhu wants the high half, which is now an explicit shift. Verified against a reference `((a as u64 * b as u64) >> 32) as u32` over edge cases including u32::MAX * u32::MAX and 0x8000_0000 * 2. `lazy_type_alias` was removed and renamed to `checked_type_aliases` (rust-lang/rust#158758). The gate is still needed, so it is just renamed. Also updates the toolchain hardcoded in .github/workflows/{ci.yml, test-gpu.yaml} and tools/reproduce/Dockerfile. Those take precedence over the rust-toolchain file, so without this CI would keep building with nightly-2026-02-10 and the pin bump would have no effect. Verified: cargo check --workspace --lib --bins --exclude fuzzing cargo check --workspace --all-targets --exclude gpu_prover --exclude fuzzing both 0 errors, and cargo fmt --all --check is clean with no changes. Exclusions are local-environment limits (no cmake, no CUDA toolkit), both of which CI covers. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Bumps the pinned toolchain from nightly-2026-02-10 to nightly-2026-08-09 (rustc 1.99.0-nightly, 771916f90) in rust-toolchain.toml, tools/verifier/rust-toolchain.toml, both workflows and tools/reproduce's Dockerfile. The workflow and Dockerfile values take precedence over the rust-toolchain file, so they have to move together. Source changes the newer compiler requires: * `u32::widening_mul` now returns the full u64 product instead of a (low, high) tuple, so `.1` no longer compiles in either mulhu. mulhu wants the high half, which is now an explicit shift; verified against a reference `((a as u64 * b as u64) >> 32) as u32` over edge cases including u32::MAX * u32::MAX and 0x8000_0000 * 2. The method also has its own `widening_mul` gate again rather than `bigint_helper_methods`. * `lazy_type_alias` was removed and renamed to `checked_type_aliases` (rust-lang/rust#158758). The gate is still needed, so it is just renamed. * `riscv_transpiler` asked for `serial_test = "*"`, which resolves to 4.0.1 and requires rustc 1.93.1. Narrowed to "3", matching every other crate. Cargo.lock is gitignored here, so the constraint has to live in Cargo.toml. * The miri job now clears rustflags, like the six other jobs in this workflow already do. Otherwise the action defaults to -Dwarnings and, under miri's cfg, target-gated features in `field` and elsewhere read as unused, turning `unused_features` into a hard error. Verified with ZKSYNC_USE_CUDA_STUBS=1: cargo check --workspace --all-targets --exclude gpu_prover --exclude fuzzing 0 errors; cargo fmt --all --check clean; `cargo miri test -p riscv_transpiler -- miri_` passes. `fuzzing` needs cmake and gpu_prover's benches need a real CUDA toolkit, both of which CI provides. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

rustbot assigned lcnr Jul 4, 2026

josetorrs commented Jul 4, 2026
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josetorrs changed the title ~~Rename lazy_type_alias to checked_free_type_aliases~~Rename lazy_type_alias feature gate to checked_free_type_aliasesJul 4, 2026

josetorrs marked this pull request as ready for review July 4, 2026 03:13

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josetorrs changed the title ~~Rename lazy_type_alias feature gate to checked_free_type_aliases~~Rename lazy_type_alias feature gate to checked_type_aliasesJul 13, 2026

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jdonszelmann mentioned this pull request Jul 16, 2026
Rollup of 6 pull requests #159383
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Rollup of 18 pull requests #159397
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Rollup of 18 pull requests #159407
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annejan mentioned this pull request Jul 31, 2026
chore: bump the nightly pin 2026-04-26 → 2026-07-30 (+ fork §11) annejan/martin#25
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annejan mentioned this pull request Jul 31, 2026
fix: rename feature gate lazy_type_alias → checked_type_aliases mosure/bevy_gaussian_splatting#237
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feat: bump nightly to 2026-08-09 matter-labs/zksync-airbender#411
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Tracking issue for checked type aliases #112792
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fmease added the F-checked_type_aliases `#![feature(checked_type_aliases)]` (formerly: `lazy_type_alias`) label Aug 22, 2026

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Rename LTA to CTA rust-lang/rustc-dev-guide#2980
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		#![feature(checked_free_type_aliases)]

		#![feature(checked_free_type_aliases)]

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