Avoid checking HIR in variances_of.

compiler/rustc_typeck/src/variance/mod.rs

@@ -3,9 +3,8 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/variance.html
 
-use hir::Node;
 use rustc_arena::DroplessArena;
-use rustc_hir as hir;
+use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, CrateVariancesMap, TyCtxt};
@@ -38,42 +37,18 @@ fn crate_variances(tcx: TyCtxt<'_>, (): ()) -> CrateVariancesMap<'_> {
 }
 
 fn variances_of(tcx: TyCtxt<'_>, item_def_id: DefId) -> &[ty::Variance] {
- let id = tcx.hir().local_def_id_to_hir_id(item_def_id.expect_local());
- let unsupported = || {
- // Variance not relevant.
- span_bug!(tcx.hir().span(id), "asked to compute variance for wrong kind of item")
- };
- match tcx.hir().get(id) {
- Node::Item(item) => match item.kind {
- hir::ItemKind::Enum(..)
- | hir::ItemKind::Struct(..)
- | hir::ItemKind::Union(..)
- | hir::ItemKind::Fn(..) => {}
-
- _ => unsupported(),
- },
-
- Node::TraitItem(item) => match item.kind {
- hir::TraitItemKind::Fn(..) => {}
-
- _ => unsupported(),
- },
-
- Node::ImplItem(item) => match item.kind {
- hir::ImplItemKind::Fn(..) => {}
-
- _ => unsupported(),
- },
-
- Node::ForeignItem(item) => match item.kind {
- hir::ForeignItemKind::Fn(..) => {}
-
- _ => unsupported(),
- },
-
- Node::Variant(_) | Node::Ctor(..) => {}
-
- _ => unsupported(),
+ match tcx.def_kind(item_def_id) {
+ DefKind::Fn
+ | DefKind::AssocFn
+ | DefKind::Enum
+ | DefKind::Struct
+ | DefKind::Union
+ | DefKind::Variant
+ | DefKind::Ctor(..) => {}
+ _ => {
+ // Variance not relevant.
+ span_bug!(tcx.def_span(item_def_id), "asked to compute variance for wrong kind of item")
+ }
  }
 
  // Everything else must be inferred.