Rollup merge of #122881 - Bryanskiy:delegation-fixes-2, r=petrochenkov

Delegation: fix ICE on `bound_vars` divergence

Fixes https://github.com/rust-lang/rust/issues/122550.

Bug was caused by divergence  between lowered type and corresponding `bound_vars` in `late_bound_vars_map`. In this patch `bound_vars` calculation for delegation item is moved from `lower_fn_ty` to `resolve_bound_vars` query.

r? `@petrochenkov`

2 files changed, 10 insertions, 8 deletions

diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index 27a26cfe474..ee3436805ca 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -793,12 +793,20 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
         fd: &'tcx hir::FnDecl<'tcx>,
         body_id: hir::BodyId,
         _: Span,
-        _: LocalDefId,
+        def_id: LocalDefId,
     ) {
         let output = match fd.output {
             hir::FnRetTy::DefaultReturn(_) => None,
             hir::FnRetTy::Return(ty) => Some(ty),
         };
+        if let Some(ty) = output
+            && let hir::TyKind::InferDelegation(sig_id, _) = ty.kind
+        {
+            let bound_vars: Vec<_> =
+                self.tcx.fn_sig(sig_id).skip_binder().bound_vars().iter().collect();
+            let hir_id = self.tcx.local_def_id_to_hir_id(def_id);
+            self.map.late_bound_vars.insert(hir_id, bound_vars);
+        }
         self.visit_fn_like_elision(fd.inputs, output, matches!(fk, intravisit::FnKind::Closure));
         intravisit::walk_fn_kind(self, fk);
         self.visit_nested_body(body_id)
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index b865bf976b5..a119ea450b4 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -2492,13 +2492,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         hir_ty: Option<&hir::Ty<'_>>,
     ) -> ty::PolyFnSig<'tcx> {
         let tcx = self.tcx();
-        let bound_vars = if let hir::FnRetTy::Return(ret_ty) = decl.output
-            && let hir::TyKind::InferDelegation(sig_id, _) = ret_ty.kind
-        {
-            tcx.fn_sig(sig_id).skip_binder().bound_vars()
-        } else {
-            tcx.late_bound_vars(hir_id)
-        };
+        let bound_vars = tcx.late_bound_vars(hir_id);
         debug!(?bound_vars);
 
         // We proactively collect all the inferred type params to emit a single error per fn def.