let the query recurse through coroutine

Author: dingxiangfei2009

compiler/rustc_middle/src/query/mod.rs

@@ -1456,7 +1456,7 @@ rustc_queries! {
     /// *IMPORTANT*: *DO NOT* run this query before promoted MIR body is constructed,
     /// because this query partially depends on that query.
     /// Otherwise, there is a risk of query cycles.
-    query list_significant_drop_tys(ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> Result<&'tcx ty::List<Ty<'tcx>>, AlwaysRequiresDrop> {
+    query list_significant_drop_tys(ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> &'tcx ty::List<Ty<'tcx>> {
         desc { |tcx| "computing when `{}` has a significant destructor", ty.value }
         cache_on_disk_if { false }
     }

compiler/rustc_mir_transform/src/lint_tail_expr_drop_order.rs

@@ -149,25 +149,11 @@ fn extract_component_raw<'tcx>(
     // Droppiness does not depend on regions, so let us erase them.
     let ty = tcx.try_normalize_erasing_regions(param_env, ty).unwrap_or(ty);
 
-    let Ok(tys) = tcx.list_significant_drop_tys(param_env.and(ty)) else {
-        return smallvec![ty];
-    };
+    let tys = tcx.list_significant_drop_tys(param_env.and(ty));
     debug!(?ty, "components");
     let mut out_tys = smallvec![];
     for ty in tys {
-        if let ty::Coroutine(did, args) = ty.kind()
-            && let Some(witness) = tcx.mir_coroutine_witnesses(did)
-        {
-            for field in &witness.field_tys {
-                out_tys.extend(extract_component_raw(
-                    tcx,
-                    param_env,
-                    ty::EarlyBinder::bind(field.ty).instantiate(tcx, args),
-                ));
-            }
-        } else {
-            out_tys.push(ty);
-        }
+        out_tys.push(ty);
     }
     out_tys
 }

compiler/rustc_ty_utils/src/needs_drop.rs

@@ -426,10 +426,19 @@ fn adt_significant_drop_tys(
 fn list_significant_drop_tys<'tcx>(
     tcx: TyCtxt<'tcx>,
     ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
-) -> Result<&'tcx ty::List<Ty<'tcx>>, AlwaysRequiresDrop> {
-    drop_tys_helper(tcx, ty.value, ty.param_env, adt_consider_insignificant_dtor(tcx), true, true)
-        .collect::<Result<Vec<_>, _>>()
-        .map(|components| tcx.mk_type_list(&components))
+) -> &'tcx ty::List<Ty<'tcx>> {
+    tcx.mk_type_list(
+        &drop_tys_helper(
+            tcx,
+            ty.value,
+            ty.param_env,
+            adt_consider_insignificant_dtor(tcx),
+            true,
+            true,
+        )
+        .filter_map(|res| res.ok())
+        .collect::<Vec<_>>(),
+    )
 }
 
 pub(crate) fn provide(providers: &mut Providers) {