diff options
Diffstat (limited to 'compiler/rustc_passes/src/stability.rs')
| -rw-r--r-- | compiler/rustc_passes/src/stability.rs | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs index adda94fda8f..e5530d52686 100644 --- a/compiler/rustc_passes/src/stability.rs +++ b/compiler/rustc_passes/src/stability.rs @@ -802,12 +802,28 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> { // FIXME(jdonszelmann): make it impossible to miss the or_else in the typesystem let const_stab = attrs::find_attr!(attrs, AttributeKind::ConstStability{stability, ..} => *stability); + let unstable_feature_stab = + find_attr!(attrs, AttributeKind::UnstableFeatureBound(i) => i) + .map(|i| i.as_slice()) + .unwrap_or_default(); + // If this impl block has an #[unstable] attribute, give an // error if all involved types and traits are stable, because // it will have no effect. // See: https://github.com/rust-lang/rust/issues/55436 + // + // The exception is when there are both #[unstable_feature_bound(..)] and + // #![unstable(feature = "..", issue = "..")] that have the same symbol because + // that can effectively mark an impl as unstable. + // + // For example: + // ``` + // #[unstable_feature_bound(feat_foo)] + // #[unstable(feature = "feat_foo", issue = "none")] + // impl Foo for Bar {} + // ``` if let Some(( - Stability { level: attrs::StabilityLevel::Unstable { .. }, .. }, + Stability { level: attrs::StabilityLevel::Unstable { .. }, feature }, span, )) = stab { @@ -815,9 +831,21 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> { c.visit_ty_unambig(self_ty); c.visit_trait_ref(t); + // Skip the lint if the impl is marked as unstable using + // #[unstable_feature_bound(..)] + let mut unstable_feature_bound_in_effect = false; + for (unstable_bound_feat_name, _) in unstable_feature_stab { + if *unstable_bound_feat_name == feature { + unstable_feature_bound_in_effect = true; + } + } + // do not lint when the trait isn't resolved, since resolution error should // be fixed first - if t.path.res != Res::Err && c.fully_stable { + if t.path.res != Res::Err + && c.fully_stable + && !unstable_feature_bound_in_effect + { self.tcx.emit_node_span_lint( INEFFECTIVE_UNSTABLE_TRAIT_IMPL, item.hir_id(), |