Rollup of 5 pull requests #148420

Zalathar · 2025-11-03T00:52:42Z

Successful merges:

Provide additional context to errors involving const traits #144194 (Provide additional context to errors involving const traits)
ci: add runners for vanilla LLVM 21 #148232 (ci: add runners for vanilla LLVM 21)
rustc_codegen: fix musttail returns for cast/indirect ABIs #148240 (rustc_codegen: fix musttail returns for cast/indirect ABIs)
Remove a special case and move another one out of reachable_non_generics #148247 (Remove a special case and move another one out of reachable_non_generics)
Point at inner item when it uses generic type param from outer item or Self #148370 (Point at inner item when it uses generic type param from outer item or Self)

r? @ghost
@rustbot modify labels: rollup

Ubuntu 25.10 has `llvm-21` packages that we can test with. The `Dockerfile` is otherwise the same as the `llvm-20` runners.

``` error[E0401]: can't use generic parameters from outer item --> $DIR/enum-definition-with-outer-generic-parameter-5997.rs:3:16 | LL | fn f<Z>() -> bool { | - type parameter from outer item LL | enum E { V(Z) } | ^ use of generic parameter from outer item | help: try introducing a local generic parameter here | LL | enum E<Z> { V(Z) } | +++ ```

``` error[E0401]: can't use generic parameters from outer item --> $DIR/E0401.rs:4:39 | LL | fn foo<T>(x: T) { | - type parameter from outer item LL | fn bfnr<U, V: Baz, W: Fn()>(y: T) { | ---- ^ use of generic parameter from outer item | | | generic parameter used in this inner function | help: try introducing a local generic parameter here | LL | fn bfnr<T, U, V: Baz, W: Fn()>(y: T) { | ++ ```

``` error[E0401]: can't reference `Self` constructor from outer item --> $DIR/do-not-ice-on-note_and_explain.rs:6:13 | LL | impl A { | ------------ the inner item doesn't inherit generics from this impl, so `Self` is invalid to reference LL | fn d() { LL | fn d() { | - `Self` used in this inner item LL | Self(1) | ^^^^ help: replace `Self` with the actual type: `A` ```

``` error[E0401]: can't use generic parameters from outer item --> $DIR/const-param-from-outer-fn.rs:3:9 | LL | fn foo<const X: u32>() { | - const parameter from outer item LL | fn bar() -> u32 { | --- generic parameter used in this inner function LL | X | ^ use of generic parameter from outer item | help: try introducing a local generic parameter here | LL | fn bar<X>() -> u32 { | +++ ```

…cs to cg_llvm This is a workaround for an LLVM bug, so put it in cg_llvm.

The panic runtime uses #[rustc_std_internal_symbol] which has the same effect as this special case with respect to symbol visibility.

When encountering an unmet `Ty: [const] Trait` bound, if `Trait` is `#[const_trait]` and there's an `impl Trait for Ty` point at it. If local, suggest `impl const Trait for Ty`, otherwise just point at it. ``` error[E0277]: the trait bound `NonConstAdd: [const] Add` is not satisfied --> $DIR/assoc-type.rs:37:16 | LL | type Bar = NonConstAdd; | ^^^^^^^^^^^ | note: required by a bound in `Foo::Bar` --> $DIR/assoc-type.rs:33:15 | LL | type Bar: [const] Add; | ^^^^^^^^^^^ required by this bound in `Foo::Bar` help: make the `impl` of trait `Add` `const` | LL | impl const Add for NonConstAdd { | +++++ ``` ``` error[E0277]: the trait bound `T: [const] PartialEq` is not satisfied --> tests/ui/traits/const-traits/call-generic-method-fail.rs:5:5 | 5 | *t == *t | ^^^^^^^^ | note: trait `PartialEq` is implemented but not `const` --> /home/gh-estebank/rust/library/core/src/ptr/const_ptr.rs:1590:1 | 1590 | impl<T: PointeeSized> PartialEq for *const T { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ note: trait `PartialEq` is implemented but not `const` --> /home/gh-estebank/rust/library/core/src/ptr/mut_ptr.rs:2011:1 | 2011 | impl<T: PointeeSized> PartialEq for *mut T { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ```

Point at trait and associated item when that associated item is used in a const context. Suggest making the trait `#[const_trait]`. ``` error[E0015]: cannot call non-const method `<() as Trait>::foo` in constant functions --> $DIR/inline-incorrect-early-bound-in-ctfe.rs:26:8 | LL | ().foo(); | ^^^^^ | note: method `foo` is not const because trait `Trait` is not const --> $DIR/inline-incorrect-early-bound-in-ctfe.rs:13:1 | LL | trait Trait { | ^^^^^^^^^^^ this trait is not const LL | fn foo(self); | ------------- this method is not const = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants help: consider making trait `Trait` const | LL + #[const_trait] LL | trait Trait { | ```

``` error[E0015]: cannot call non-const associated function `Foo::{constant#0}::Foo::<17>::value` in constants --> $DIR/nested-type.rs:15:5 | LL | struct Foo<const N: [u8; { | __________________________- LL | | struct Foo<const N: usize>; LL | | LL | | impl<const N: usize> Foo<N> { ... | LL | | Foo::<17>::value() | | ^^^^^^^^^^^^^^^^^^ LL | | LL | | }]>; | |_- calls in constants are limited to constant functions, tuple structs and tuple variants ```

Provide additional context to errors involving const traits When encountering an unmet `Ty: [const] Trait` bound, if `Trait` is `#[const_trait]` and there's an `impl Trait for Ty` point at it. If local, suggest `impl const Trait for Ty`, otherwise just point at it. ``` error[E0277]: the trait bound `NonConstAdd: [const] Add` is not satisfied --> $DIR/assoc-type.rs:37:16 | LL | type Bar = NonConstAdd; | ^^^^^^^^^^^ | note: required by a bound in `Foo::Bar` --> $DIR/assoc-type.rs:33:15 | LL | type Bar: [const] Add; | ^^^^^^^^^^^ required by this bound in `Foo::Bar` help: make the `impl` of trait `Add` `const` | LL | impl const Add for NonConstAdd { | +++++ ``` ``` error[E0277]: the trait bound `T: [const] PartialEq` is not satisfied --> tests/ui/traits/const-traits/call-generic-method-fail.rs:5:5 | 5 | *t == *t | ^^^^^^^^ | note: trait `PartialEq` is implemented but not `const` --> /home/gh-estebank/rust/library/core/src/ptr/const_ptr.rs:1590:1 | 1590 | impl<T: PointeeSized> PartialEq for *const T { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ note: trait `PartialEq` is implemented but not `const` --> /home/gh-estebank/rust/library/core/src/ptr/mut_ptr.rs:2011:1 | 2011 | impl<T: PointeeSized> PartialEq for *mut T { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ```

ci: add runners for vanilla LLVM 21 Ubuntu 25.10 has `llvm-21` packages that we can test with. The `Dockerfile` is otherwise the same as the `llvm-20` runners.

…fleLapkin rustc_codegen: fix musttail returns for cast/indirect ABIs Fixes rust-lang#148239 rust-lang#144986 Explicit tail calls trigger `bug!` for any callee whose ABI returns via `PassMode::Cast`, and we forgot to to forward the hidden `sret` out-pointer when the ABI requested an indirect return. The former causes ICE, the latter produced malformed IR (wrong codegen) if the return value is large enough to need `sret`. Updated the musttail helper to accept cast-mode returns, made it so that we pass the return pointer through the tail-call path. Added two UI tests to demonstrate each case. This is my first time contributing, please do check if I did it right. r? theemathas

…, r=WaffleLapkin Remove a special case and move another one out of reachable_non_generics One is no longer necessary, the other is best placed in cg_llvm as it works around a cg_llvm bug.

…ouwer Point at inner item when it uses generic type param from outer item or `Self` Partially address rust-lang#37892. In E0401 generated in resolve: ``` error[E0401]: can't use generic parameters from outer item --> $DIR/E0401.rs:4:39 | LL | fn foo<T>(x: T) { | - type parameter from outer item LL | fn bfnr<U, V: Baz, W: Fn()>(y: T) { | ---- ^ use of generic parameter from outer item | | | generic parameter used in this inner function | help: try introducing a local generic parameter here | LL | fn bfnr<T, U, V: Baz, W: Fn()>(y: T) { | ++ ``` In E0401 generated in hir_typeck: ``` error[E0401]: can't reference `Self` constructor from outer item --> $DIR/do-not-ice-on-note_and_explain.rs:6:13 | LL | impl A { | ------------ the inner item doesn't inherit generics from this impl, so `Self` is invalid to reference LL | fn d() { LL | fn d() { | - `Self` used in this inner item LL | Self(1) | ^^^^ help: replace `Self` with the actual type: `A` ```

Zalathar · 2025-11-03T00:53:05Z

Rollup of everything not in #148412.

@bors r+ rollup=never p=5

bors · 2025-11-03T00:53:08Z

📌 Commit c10e1e4 has been approved by Zalathar

It is now in the queue for this repository.

bors · 2025-11-03T02:52:04Z

⌛ Testing commit c10e1e4 with merge 7878a91...

Zalathar · 2025-11-03T03:29:01Z

If this rollup fails for any reason, please prefer to create a newer, larger rollup. No reason to retry this particular subset of PRs.

bors · 2025-11-03T06:35:34Z

☀️ Test successful - checks-actions
Approved by: Zalathar
Pushing 7878a91 to master...

rust-timer · 2025-11-03T06:37:03Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#144194	Provide additional context to errors involving const traits	`949baf3133f9742cadb3052ddd125689db6e89f1` (link)
#148232	ci: add runners for vanilla LLVM 21	`c5262e25be0e7989a18e5c4f20510483b1409822` (link)
#148240	rustc_codegen: fix musttail returns for cast/indirect ABIs	`6ac183251fdef6f35336a9604f49ca65b3b6417b` (link)
#148247	Remove a special case and move another one out of reachable…	`6c0c58f00086ee4deeeb3d8eee6e16cc25a3e926` (link)
#148370	Point at inner item when it uses generic type param from ou…	`0ce76d8861244de42a0552032ee7aed51acaef96` (link)

previous master: c5dabe8cf7

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

github-actions · 2025-11-03T06:38:31Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing c5dabe8 (parent) -> 7878a91 (this PR)

Test differences

Show 46 test diffs

Stage 1

[ui] tests/ui/explicit-tail-calls/become-cast-return.rs: [missing] -> pass (J0)
[ui] tests/ui/explicit-tail-calls/become-indirect-return.rs: [missing] -> pass (J0)

Stage 2

[ui] tests/ui/explicit-tail-calls/become-cast-return.rs: [missing] -> pass (J1)
[ui] tests/ui/explicit-tail-calls/become-indirect-return.rs: [missing] -> pass (J1)
[ui] tests/ui/explicit-tail-calls/become-cast-return.rs: [missing] -> ignore (ignored when cross-compiling) (J2)
[ui] tests/ui/explicit-tail-calls/become-indirect-return.rs: [missing] -> ignore (ignored when cross-compiling) (J2)
[ui] tests/ui/explicit-tail-calls/become-cast-return.rs: [missing] -> ignore (gcc backend is marked as ignore) (J3)
[ui] tests/ui/explicit-tail-calls/become-indirect-return.rs: [missing] -> ignore (gcc backend is marked as ignore) (J3)

Additionally, 38 doctest diffs were found. These are ignored, as they are noisy.

Job group index

J0: x86_64-gnu-llvm-20-3
J1: aarch64-apple, aarch64-gnu, aarch64-gnu-llvm-20-1, aarch64-msvc-1, i686-gnu-1, i686-gnu-nopt-1, i686-msvc-1, x86_64-gnu, x86_64-gnu-debug, x86_64-gnu-nopt, x86_64-gnu-stable, x86_64-mingw-1, x86_64-msvc-1
J2: arm-android, armhf-gnu, dist-i586-gnu-i586-i686-musl, test-various, x86_64-gnu-llvm-20, x86_64-gnu-llvm-20-2
J3: x86_64-gnu-gcc

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 7878a919448eb219b630d1866ca06c0d412483f2 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

pr-check-1: 1497.2s -> 1918.7s (+28.1%)
pr-check-2: 2735.1s -> 2332.1s (-14.7%)
dist-x86_64-windows-gnullvm: 5308.3s -> 4588.1s (-13.6%)
dist-aarch64-msvc: 5271.4s -> 5980.3s (+13.4%)
x86_64-gnu-llvm-20-2: 5951.2s -> 5254.5s (-11.7%)
dist-apple-various: 3490.3s -> 3871.7s (+10.9%)
dist-i686-linux: 6645.7s -> 5977.8s (-10.1%)
dist-various-1: 3991.3s -> 4347.6s (+8.9%)
dist-x86_64-apple: 5622.9s -> 6097.9s (+8.4%)
dist-x86_64-musl: 7852.1s -> 7207.9s (-8.2%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2025-11-03T07:46:21Z

Finished benchmarking commit (7878a91): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary -2.8%, secondary 0.7%)

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

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	0.7%	[0.7%, 0.7%]	1
Improvements ✅ (primary)	-5.4%	[-8.6%, -2.2%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.8%	[-8.6%, 2.4%]	3

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 474.179s -> 475.242s (0.22%)
Artifact size: 390.90 MiB -> 390.89 MiB (-0.00%)

cuviper and others added 25 commits October 28, 2025 15:27

ci: add runners for vanilla LLVM 21

46a474b

Ubuntu 25.10 has `llvm-21` packages that we can test with. The `Dockerfile` is otherwise the same as the `llvm-20` runners.

Add tests to demonstrate explicit tail call bug

3a02b35

Fix musttail returns for cast/indirect ABIs

52959a8

Pass DiagMetadata through in more cases

86d7556

Fix CI failure by ignoring wasm target and cross compile run

72c9762

Move a special case for rust_eh_personality from reachable_non_generi…

964d3af

…cs to cg_llvm This is a workaround for an LLVM bug, so put it in cg_llvm.

Remove special case for the panic runtime from reachable_non_generics

e8d88c0

The panic runtime uses #[rustc_std_internal_symbol] which has the same effect as this special case with respect to symbol visibility.

review comments

c962b95

Do not suggest adding type param to fn delegation

f171c41

Only suggest #[const_trait] only on local traits

eb79e68

Account for #![feature(const_trait_impl)] state

bf45da7

review comments

a2c3913

fix rebase

74b7592

Rollup merge of rust-lang#148232 - cuviper:ci-llvm-21, r=Mark-Simulacrum

a44b547

ci: add runners for vanilla LLVM 21 Ubuntu 25.10 has `llvm-21` packages that we can test with. The `Dockerfile` is otherwise the same as the `llvm-20` runners.

Rollup merge of rust-lang#148247 - bjorn3:minor_symbol_export_cleanup…

4b28573

…, r=WaffleLapkin Remove a special case and move another one out of reachable_non_generics One is no longer necessary, the other is best placed in cg_llvm as it works around a cg_llvm bug.

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Nov 3, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Nov 3, 2025

bors merged commit 7878a91 into rust-lang:master Nov 3, 2025
12 checks passed

rustbot added this to the 1.93.0 milestone Nov 3, 2025

Zalathar deleted the rollup-1rrbzk7 branch November 3, 2025 06:51

This was referenced Nov 3, 2025

Fix issue with callsite inline attribute not being applied sometimes. #147404

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Mangle personality symbol #148413

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Overall result: no relevant changes - no action needed

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