diff options
| -rw-r--r-- | clippy_lints/src/empty_enum.rs | 15 | ||||
| -rw-r--r-- | tests/ui/empty_enum_without_never_type.rs | 7 |
2 files changed, 16 insertions, 6 deletions
diff --git a/clippy_lints/src/empty_enum.rs b/clippy_lints/src/empty_enum.rs index 557a7c6ba98..4533d6447a7 100644 --- a/clippy_lints/src/empty_enum.rs +++ b/clippy_lints/src/empty_enum.rs @@ -8,12 +8,12 @@ use rustc_session::{declare_lint_pass, declare_tool_lint}; declare_clippy_lint! { /// **What it does:** Checks for `enum`s with no variants. /// - /// As of this writing, the never type is still a + /// As of this writing, the `never_type` is still a /// nightly-only experimental API. Therefore, this lint is only triggered - /// if the never type is enabled + /// if the `never_type` is enabled. /// /// **Why is this bad?** If you want to introduce a type which - /// can't be instantiated, you should use `!` (the never type), + /// can't be instantiated, you should use `!` (the primitive type never), /// or a wrapper around it, because `!` has more extensive /// compiler support (type inference, etc...) and wrappers /// around it are the conventional way to define an uninhabited type. @@ -44,13 +44,16 @@ declare_lint_pass!(EmptyEnum => [EMPTY_ENUM]); impl<'tcx> LateLintPass<'tcx> for EmptyEnum { fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) { + // Only suggest the `never_type` if the feature is enabled + if !cx.tcx.features().never_type { + return; + } + let did = cx.tcx.hir().local_def_id(item.hir_id); if let ItemKind::Enum(..) = item.kind { let ty = cx.tcx.type_of(did); let adt = ty.ty_adt_def().expect("already checked whether this is an enum"); - - // Only suggest the never type if the feature is enabled - if adt.variants.is_empty() && cx.tcx.features().never_type { + if adt.variants.is_empty() { span_lint_and_help( cx, EMPTY_ENUM, diff --git a/tests/ui/empty_enum_without_never_type.rs b/tests/ui/empty_enum_without_never_type.rs new file mode 100644 index 00000000000..4cbdfc47910 --- /dev/null +++ b/tests/ui/empty_enum_without_never_type.rs @@ -0,0 +1,7 @@ +#![allow(dead_code)] +#![warn(clippy::empty_enum)] + +// `never_type` is not enabled; this test has no stderr file +enum Empty {} + +fn main() {} \ No newline at end of file |