Refactor empty_enums: Check the HIR tree before the feature check.

This commit is contained in:
Jason Newcomb 2024-06-09 22:32:55 -04:00
parent d1dcd918e7
commit 672b8b512a

View file

@ -64,25 +64,21 @@ 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;
}
if let ItemKind::Enum(..) = item.kind {
let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
if adt.variants().is_empty() {
span_lint_and_help(
cx,
EMPTY_ENUM,
item.span,
"enum with no variants",
None,
"consider using the uninhabited type `!` (never type) or a wrapper \
around it to introduce a type which can't be instantiated",
);
}
if let ItemKind::Enum(..) = item.kind
// Only suggest the `never_type` if the feature is enabled
&& cx.tcx.features().never_type
&& let Some(adt) = cx.tcx.type_of(item.owner_id).instantiate_identity().ty_adt_def()
&& adt.variants().is_empty()
{
span_lint_and_help(
cx,
EMPTY_ENUM,
item.span,
"enum with no variants",
None,
"consider using the uninhabited type `!` (never type) or a wrapper \
around it to introduce a type which can't be instantiated",
);
}
}
}