diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index db396356d6711..19c3385dd4cbc 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -1878,6 +1878,10 @@ impl<'v> Visitor<'v> for FindTypeParam { hir::intravisit::NestedVisitorMap::None } + fn visit_where_predicate(&mut self, _: &'v hir::WherePredicate<'v>) { + // Skip where-clauses, to avoid suggesting indirection for type parameters found there. + } + fn visit_ty(&mut self, ty: &hir::Ty<'_>) { // We collect the spans of all uses of the "bare" type param, like in `field: T` or // `field: (T, T)` where we could make `T: ?Sized` while skipping cases that are known to be diff --git a/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs b/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs new file mode 100644 index 0000000000000..390d8bbdd5326 --- /dev/null +++ b/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs @@ -0,0 +1,9 @@ +// Regression test for #85943: should not emit suggestions for adding +// indirection to type parameters in where-clauses when suggesting +// adding `?Sized`. +struct A(T) where T: Send; +struct B(A<[u8]>); +//~^ ERROR the size for values of type + +pub fn main() { +} diff --git a/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.stderr b/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.stderr new file mode 100644 index 0000000000000..735aeb0e0e799 --- /dev/null +++ b/src/test/ui/suggestions/issue-85943-no-suggest-unsized-indirection-in-where-clause.stderr @@ -0,0 +1,20 @@ +error[E0277]: the size for values of type `[u8]` cannot be known at compilation time + --> $DIR/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs:5:10 + | +LL | struct A(T) where T: Send; + | - required by this bound in `A` +LL | struct B(A<[u8]>); + | ^^^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u8]` +help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box` + --> $DIR/issue-85943-no-suggest-unsized-indirection-in-where-clause.rs:4:10 + | +LL | struct A(T) where T: Send; + | ^ - ...if indirection were used here: `Box` + | | + | this could be changed to `T: ?Sized`... + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`.