diff options
4 files changed, 52 insertions, 1 deletions
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index a9eb1739f7f..df9f3a500d9 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -1340,7 +1340,15 @@ impl EarlyLintPass for UnusedParens { self.with_self_ty_parens = false; } ast::TyKind::Ref(_, mut_ty) | ast::TyKind::Ptr(mut_ty) => { - self.in_no_bounds_pos.insert(mut_ty.ty.id, NoBoundsException::OneBound); + // If this type itself appears in no-bounds position, we propagate its + // potentially tighter constraint or risk a false posive (issue 143653). + let own_constraint = self.in_no_bounds_pos.get(&ty.id); + let constraint = match own_constraint { + Some(NoBoundsException::None) => NoBoundsException::None, + Some(NoBoundsException::OneBound) => NoBoundsException::OneBound, + None => NoBoundsException::OneBound, + }; + self.in_no_bounds_pos.insert(mut_ty.ty.id, constraint); } ast::TyKind::TraitObject(bounds, _) | ast::TyKind::ImplTrait(_, bounds) => { for i in 0..bounds.len() { diff --git a/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.fixed b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.fixed new file mode 100644 index 00000000000..4b0bca3d44a --- /dev/null +++ b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.fixed @@ -0,0 +1,12 @@ +//@ run-rustfix + +#![deny(unused_parens)] +#![allow(warnings)] +trait MyTrait {} + +fn foo(_: Box<dyn FnMut(&mut u32) -> &mut (dyn MyTrait) + Send + Sync>) {} + +//~v ERROR unnecessary parentheses around type +fn bar(_: Box<dyn FnMut(&mut u32) -> &mut dyn MyTrait>) {} + +fn main() {} diff --git a/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.rs b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.rs new file mode 100644 index 00000000000..4eefd3dc81a --- /dev/null +++ b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.rs @@ -0,0 +1,12 @@ +//@ run-rustfix + +#![deny(unused_parens)] +#![allow(warnings)] +trait MyTrait {} + +fn foo(_: Box<dyn FnMut(&mut u32) -> &mut (dyn MyTrait) + Send + Sync>) {} + +//~v ERROR unnecessary parentheses around type +fn bar(_: Box<dyn FnMut(&mut u32) -> &mut (dyn MyTrait)>) {} + +fn main() {} diff --git a/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.stderr b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.stderr new file mode 100644 index 00000000000..89455e3db73 --- /dev/null +++ b/tests/ui/lint/unused/unused-parens-false-positive-issue-143653.stderr @@ -0,0 +1,19 @@ +error: unnecessary parentheses around type + --> $DIR/unused-parens-false-positive-issue-143653.rs:10:43 + | +LL | fn bar(_: Box<dyn FnMut(&mut u32) -> &mut (dyn MyTrait)>) {} + | ^ ^ + | +note: the lint level is defined here + --> $DIR/unused-parens-false-positive-issue-143653.rs:3:9 + | +LL | #![deny(unused_parens)] + | ^^^^^^^^^^^^^ +help: remove these parentheses + | +LL - fn bar(_: Box<dyn FnMut(&mut u32) -> &mut (dyn MyTrait)>) {} +LL + fn bar(_: Box<dyn FnMut(&mut u32) -> &mut dyn MyTrait>) {} + | + +error: aborting due to 1 previous error + |