diff --git a/compiler/rustc_hir_typeck/src/check.rs b/compiler/rustc_hir_typeck/src/check.rs index bf8259ff70f..3e5d808325c 100644 --- a/compiler/rustc_hir_typeck/src/check.rs +++ b/compiler/rustc_hir_typeck/src/check.rs @@ -32,6 +32,7 @@ pub(super) fn check_fn<'a, 'tcx>( fn_def_id: LocalDefId, body: &'tcx hir::Body<'tcx>, can_be_generator: Option, + params_can_be_unsized: bool, ) -> Option> { let fn_id = fcx.tcx.hir().local_def_id_to_hir_id(fn_def_id); @@ -94,7 +95,7 @@ pub(super) fn check_fn<'a, 'tcx>( // The check for a non-trivial pattern is a hack to avoid duplicate warnings // for simple cases like `fn foo(x: Trait)`, // where we would error once on the parameter as a whole, and once on the binding `x`. - if param.pat.simple_ident().is_none() && !tcx.features().unsized_fn_params { + if param.pat.simple_ident().is_none() && !params_can_be_unsized { fcx.require_type_is_sized(param_ty, param.pat.span, traits::SizedArgumentType(ty_span)); } diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs index 7046269c2de..9659a0ec13d 100644 --- a/compiler/rustc_hir_typeck/src/closure.rs +++ b/compiler/rustc_hir_typeck/src/closure.rs @@ -89,6 +89,8 @@ fn check_closure( expr_def_id, body, closure.movability, + // Closure "rust-call" ABI doesn't support unsized params + false, ); let parent_substs = InternalSubsts::identity_for_item( diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs index 64426c4cbbb..b97b55d8f7e 100644 --- a/compiler/rustc_hir_typeck/src/lib.rs +++ b/compiler/rustc_hir_typeck/src/lib.rs @@ -212,7 +212,7 @@ fn typeck_with_fallback<'tcx>( let fn_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), fn_sig); let fn_sig = fcx.normalize(body.value.span, fn_sig); - check_fn(&mut fcx, fn_sig, decl, def_id, body, None); + check_fn(&mut fcx, fn_sig, decl, def_id, body, None, tcx.features().unsized_fn_params); } else { let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = body_ty { Some(fcx.next_ty_var(TypeVariableOrigin { diff --git a/tests/ui/unsized-locals/issue-67981.rs b/tests/ui/unsized-locals/issue-67981.rs new file mode 100644 index 00000000000..3eb6498e9dc --- /dev/null +++ b/tests/ui/unsized-locals/issue-67981.rs @@ -0,0 +1,9 @@ +#![feature(unsized_fn_params)] + +fn main() { + let f: fn([u8]) = |_| {}; + //~^ERROR the size for values of type `[u8]` cannot be known at compilation time + let slice: Box<[u8]> = Box::new([1; 8]); + + f(*slice); +} diff --git a/tests/ui/unsized-locals/issue-67981.stderr b/tests/ui/unsized-locals/issue-67981.stderr new file mode 100644 index 00000000000..a4b179ae2fd --- /dev/null +++ b/tests/ui/unsized-locals/issue-67981.stderr @@ -0,0 +1,15 @@ +error[E0277]: the size for values of type `[u8]` cannot be known at compilation time + --> $DIR/issue-67981.rs:4:24 + | +LL | let f: fn([u8]) = |_| {}; + | ^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u8]` +help: function arguments must have a statically known size, borrowed types always have a known size + | +LL | let f: fn([u8]) = |&_| {}; + | + + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`.