Lower AST and resolve lifetimes for unsafe binder types

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -470,6 +470,12 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option<S
                     self.outer_index.shift_out(1);
                     res
                 }
+                hir::TyKind::UnsafeBinder(_) => {
+                    self.outer_index.shift_in(1);
+                    let res = intravisit::walk_ty(self, ty);
+                    self.outer_index.shift_out(1);
+                    res
+                }
                 _ => intravisit::walk_ty(self, ty),
             }
         }

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -781,6 +781,36 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
                     intravisit::walk_ty(this, ty);
                 });
             }
+            hir::TyKind::UnsafeBinder(binder) => {
+                let (mut bound_vars, binders): (FxIndexMap<LocalDefId, ResolvedArg>, Vec<_>) =
+                    binder
+                        .generic_params
+                        .iter()
+                        .enumerate()
+                        .map(|(late_bound_idx, param)| {
+                            (
+                                (param.def_id, ResolvedArg::late(late_bound_idx as u32, param)),
+                                late_arg_as_bound_arg(self.tcx, param),
+                            )
+                        })
+                        .unzip();
+
+                deny_non_region_late_bound(self.tcx, &mut bound_vars, "function pointer types");
+
+                self.record_late_bound_vars(ty.hir_id, binders);
+                let scope = Scope::Binder {
+                    hir_id: ty.hir_id,
+                    bound_vars,
+                    s: self.scope,
+                    scope_type: BinderScopeType::Normal,
+                    where_bound_origin: None,
+                };
+                self.with(scope, |this| {
+                    // a bare fn has no bounds, so everything
+                    // contained within is scoped within its binder.
+                    intravisit::walk_ty(this, ty);
+                });
+            }
             hir::TyKind::TraitObject(bounds, lifetime, _) => {
                 debug!(?bounds, ?lifetime, "TraitObject");
                 let scope = Scope::TraitRefBoundary { s: self.scope };

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2312,6 +2312,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                     self.lower_fn_ty(hir_ty.hir_id, bf.safety, bf.abi, bf.decl, None, Some(hir_ty)),
                 )
             }
+            hir::TyKind::UnsafeBinder(_binder) => {
+                let guar = self
+                    .dcx()
+                    .struct_span_err(hir_ty.span, "unsafe binders are not yet implemented")
+                    .emit();
+                Ty::new_error(tcx, guar)
+            }
             hir::TyKind::TraitObject(bounds, lifetime, repr) => {
                 if let Some(guar) = self.prohibit_or_lint_bare_trait_object_ty(hir_ty) {
                     // Don't continue with type analysis if the `dyn` keyword is missing