diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs index ffddf6f73aaf0..1ef0cbb39ebf4 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs @@ -2557,27 +2557,29 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // reject function types that violate cmse ABI requirements cmse::validate_cmse_abi(self.tcx(), self.dcx(), hir_id, abi, bare_fn_ty); - // Find any late-bound regions declared in return type that do - // not appear in the arguments. These are not well-formed. - // - // Example: - // for<'a> fn() -> &'a str <-- 'a is bad - // for<'a> fn(&'a String) -> &'a str <-- 'a is ok - let inputs = bare_fn_ty.inputs(); - let late_bound_in_args = - tcx.collect_constrained_late_bound_regions(inputs.map_bound(|i| i.to_owned())); - let output = bare_fn_ty.output(); - let late_bound_in_ret = tcx.collect_referenced_late_bound_regions(output); - - self.validate_late_bound_regions(late_bound_in_args, late_bound_in_ret, |br_name| { - struct_span_code_err!( - self.dcx(), - decl.output.span(), - E0581, - "return type references {}, which is not constrained by the fn input types", - br_name - ) - }); + if !bare_fn_ty.references_error() { + // Find any late-bound regions declared in return type that do + // not appear in the arguments. These are not well-formed. + // + // Example: + // for<'a> fn() -> &'a str <-- 'a is bad + // for<'a> fn(&'a String) -> &'a str <-- 'a is ok + let inputs = bare_fn_ty.inputs(); + let late_bound_in_args = + tcx.collect_constrained_late_bound_regions(inputs.map_bound(|i| i.to_owned())); + let output = bare_fn_ty.output(); + let late_bound_in_ret = tcx.collect_referenced_late_bound_regions(output); + + self.validate_late_bound_regions(late_bound_in_args, late_bound_in_ret, |br_name| { + struct_span_code_err!( + self.dcx(), + decl.output.span(), + E0581, + "return type references {}, which is not constrained by the fn input types", + br_name + ) + }); + } bare_fn_ty } diff --git a/tests/ui/async-await/unconstrained-lifetimes.rs b/tests/ui/async-await/unconstrained-lifetimes.rs new file mode 100644 index 0000000000000..50ab7bae73d4f --- /dev/null +++ b/tests/ui/async-await/unconstrained-lifetimes.rs @@ -0,0 +1,9 @@ +//@ edition: 2021 + +// Make sure we don't complain about the implicit `-> impl Future` capturing an +// unconstrained anonymous lifetime. + +async fn foo(_: Missing<'_>) {} +//~^ ERROR cannot find type `Missing` in this scope + +fn main() {} diff --git a/tests/ui/async-await/unconstrained-lifetimes.stderr b/tests/ui/async-await/unconstrained-lifetimes.stderr new file mode 100644 index 0000000000000..18a46a3b55518 --- /dev/null +++ b/tests/ui/async-await/unconstrained-lifetimes.stderr @@ -0,0 +1,9 @@ +error[E0412]: cannot find type `Missing` in this scope + --> $DIR/unconstrained-lifetimes.rs:6:17 + | +LL | async fn foo(_: Missing<'_>) {} + | ^^^^^^^ not found in this scope + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0412`.