Don't call own_existential_vtable_entries on unresolved trait ref

Author: compiler-errors

compiler/rustc_middle/src/query/mod.rs

@@ -1207,9 +1207,9 @@ rustc_queries! {
     }
 
     query own_existential_vtable_entries(
-        key: ty::PolyExistentialTraitRef<'tcx>
+        key: DefId
     ) -> &'tcx [DefId] {
-        desc { |tcx| "finding all existential vtable entries for trait `{}`", tcx.def_path_str(key.def_id()) }
+        desc { |tcx| "finding all existential vtable entries for trait `{}`", tcx.def_path_str(key) }
     }
 
     query vtable_entries(key: ty::PolyTraitRef<'tcx>)

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -764,12 +764,9 @@ fn dump_vtable_entries<'tcx>(
     });
 }
 
-fn own_existential_vtable_entries<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    trait_ref: ty::PolyExistentialTraitRef<'tcx>,
-) -> &'tcx [DefId] {
+fn own_existential_vtable_entries<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId) -> &'tcx [DefId] {
     let trait_methods = tcx
-        .associated_items(trait_ref.def_id())
+        .associated_items(trait_def_id)
         .in_definition_order()
         .filter(|item| item.kind == ty::AssocKind::Fn);
     // Now list each method's DefId (for within its trait).
@@ -778,7 +775,7 @@ fn own_existential_vtable_entries<'tcx>(
         let def_id = trait_method.def_id;
 
         // Some methods cannot be called on an object; skip those.
-        if !is_vtable_safe_method(tcx, trait_ref.def_id(), &trait_method) {
+        if !is_vtable_safe_method(tcx, trait_def_id, &trait_method) {
             debug!("own_existential_vtable_entry: not vtable safe");
             return None;
         }
@@ -810,7 +807,7 @@ fn vtable_entries<'tcx>(
 
                 // Lookup the shape of vtable for the trait.
                 let own_existential_entries =
-                    tcx.own_existential_vtable_entries(existential_trait_ref);
+                    tcx.own_existential_vtable_entries(existential_trait_ref.def_id());
 
                 let own_entries = own_existential_entries.iter().copied().map(|def_id| {
                     debug!("vtable_entries: trait_method={:?}", def_id);

compiler/rustc_trait_selection/src/traits/util.rs

@@ -268,10 +268,7 @@ pub fn count_own_vtable_entries<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>,
 ) -> usize {
-    let existential_trait_ref =
-        trait_ref.map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref));
-    let existential_trait_ref = tcx.erase_regions(existential_trait_ref);
-    tcx.own_existential_vtable_entries(existential_trait_ref).len()
+    tcx.own_existential_vtable_entries(trait_ref.def_id()).len()
 }
 
 /// Given an upcast trait object described by `object`, returns the
@@ -282,15 +279,10 @@ pub fn get_vtable_index_of_object_method<'tcx, N>(
     object: &super::ImplSourceObjectData<'tcx, N>,
     method_def_id: DefId,
 ) -> Option<usize> {
-    let existential_trait_ref = object
-        .upcast_trait_ref
-        .map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref));
-    let existential_trait_ref = tcx.erase_regions(existential_trait_ref);
-
     // Count number of methods preceding the one we are selecting and
     // add them to the total offset.
     if let Some(index) = tcx
-        .own_existential_vtable_entries(existential_trait_ref)
+        .own_existential_vtable_entries(object.upcast_trait_ref.def_id())
         .iter()
         .copied()
         .position(|def_id| def_id == method_def_id)