From 2111525850863ec2f4c14c964ae37a761de64f63 Mon Sep 17 00:00:00 2001 From: xizheyin Date: Fri, 4 Jul 2025 20:54:45 +0800 Subject: [PATCH 1/2] Add test false-sealed-traits-note.rs Signed-off-by: xizheyin --- .../sealed-traits/false-sealed-traits-note.rs | 13 ++++++++++++ .../false-sealed-traits-note.stderr | 21 +++++++++++++++++++ 2 files changed, 34 insertions(+) create mode 100644 tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs create mode 100644 tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr diff --git a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs new file mode 100644 index 0000000000000..75bc11b067873 --- /dev/null +++ b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs @@ -0,0 +1,13 @@ +// when we impl TraitA for Struct, it can compile, we should not emit sealed traits note, see issue #143392 + +mod inner { + pub trait TraitA {} + + pub trait TraitB: TraitA {} +} + +struct Struct; + +impl inner::TraitB for Struct {} //~ ERROR the trait bound `Struct: TraitA` is not satisfied [E0277] + +fn main(){} \ No newline at end of file diff --git a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr new file mode 100644 index 0000000000000..3855516028568 --- /dev/null +++ b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr @@ -0,0 +1,21 @@ +error[E0277]: the trait bound `Struct: TraitA` is not satisfied + --> $DIR/false-sealed-traits-note.rs:11:24 + | +LL | impl inner::TraitB for Struct {} + | ^^^^^^ the trait `TraitA` is not implemented for `Struct` + | +help: this trait has no implementations, consider adding one + --> $DIR/false-sealed-traits-note.rs:4:5 + | +LL | pub trait TraitA {} + | ^^^^^^^^^^^^^^^^ +note: required by a bound in `TraitB` + --> $DIR/false-sealed-traits-note.rs:6:23 + | +LL | pub trait TraitB: TraitA {} + | ^^^^^^ required by this bound in `TraitB` + = note: `TraitB` is a "sealed trait", because to implement it you also need to implement `inner::TraitA`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0277`. From 4a261a15131e5eec10252d5131c8a3c3f89edbf7 Mon Sep 17 00:00:00 2001 From: xizheyin Date: Fri, 4 Jul 2025 21:38:46 +0800 Subject: [PATCH 2/2] Use relative visibility when noting sealed trait to reduce false positive Signed-off-by: xizheyin --- .../src/error_reporting/traits/suggestions.rs | 20 ++++++++++++++----- .../sealed-traits/false-sealed-traits-note.rs | 4 ++-- .../false-sealed-traits-note.stderr | 1 - 3 files changed, 17 insertions(+), 8 deletions(-) diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs index 362052e9fdbdd..dda517074f412 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs @@ -22,6 +22,7 @@ use rustc_hir::{ expr_needs_parens, is_range_literal, }; use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes, InferCtxt, InferOk}; +use rustc_middle::middle::privacy::Level; use rustc_middle::traits::IsConstable; use rustc_middle::ty::error::TypeError; use rustc_middle::ty::print::{ @@ -2775,11 +2776,20 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { ty::ClauseKind::Trait(trait_pred) => { let def_id = trait_pred.def_id(); let visible_item = if let Some(local) = def_id.as_local() { - // Check for local traits being reachable. - let vis = &tcx.resolutions(()).effective_visibilities; - // Account for non-`pub` traits in the root of the local crate. - let is_locally_reachable = tcx.parent(def_id).is_crate_root(); - vis.is_reachable(local) || is_locally_reachable + let ty = trait_pred.self_ty(); + // when `TraitA: TraitB` and `S` only impl TraitA, + // we check if `TraitB` can be reachable from `S` + // to determine whether to note `TraitA` is sealed trait. + if let ty::Adt(adt, _) = ty.kind() { + let visibilities = tcx.effective_visibilities(()); + visibilities.effective_vis(local).is_none_or(|v| { + v.at_level(Level::Reexported) + .is_accessible_from(adt.did(), tcx) + }) + } else { + // FIXME(xizheyin): if the type is not ADT, we should not suggest it + true + } } else { // Check for foreign traits being reachable. tcx.visible_parent_map(()).get(&def_id).is_some() diff --git a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs index 75bc11b067873..13f3065e442e5 100644 --- a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs +++ b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.rs @@ -1,4 +1,4 @@ -// when we impl TraitA for Struct, it can compile, we should not emit sealed traits note, see issue #143392 +// We should not emit sealed traits note, see issue #143392 mod inner { pub trait TraitA {} @@ -10,4 +10,4 @@ struct Struct; impl inner::TraitB for Struct {} //~ ERROR the trait bound `Struct: TraitA` is not satisfied [E0277] -fn main(){} \ No newline at end of file +fn main(){} diff --git a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr index 3855516028568..f80d985ad6e63 100644 --- a/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr +++ b/tests/ui/privacy/sealed-traits/false-sealed-traits-note.stderr @@ -14,7 +14,6 @@ note: required by a bound in `TraitB` | LL | pub trait TraitB: TraitA {} | ^^^^^^ required by this bound in `TraitB` - = note: `TraitB` is a "sealed trait", because to implement it you also need to implement `inner::TraitA`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it error: aborting due to 1 previous error