Rollup merge of #139348 - meithecatte:async-destructor-minify, r=petrochenkov

AsyncDestructor: replace fields with impl_did

The future and ctor fields aren't actually used, and the way they are extracted is obviously wrong – swapping the order of the items in the source code will give wrong results.

Instead, store just the LocalDefId of the impl, which is enough for the only use of this data.

3 files changed, 6 insertions, 17 deletions

diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 255d464d265..23955f91118 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1124,10 +1124,8 @@ pub struct Destructor {
 // FIXME: consider combining this definition with regular `Destructor`
 #[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)]
 pub struct AsyncDestructor {
-    /// The `DefId` of the async destructor future constructor
-    pub ctor: DefId,
-    /// The `DefId` of the async destructor future type
-    pub future: DefId,
+    /// The `DefId` of the `impl AsyncDrop`
+    pub impl_did: LocalDefId,
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)]
diff --git a/compiler/rustc_middle/src/ty/significant_drop_order.rs b/compiler/rustc_middle/src/ty/significant_drop_order.rs
index 2d9e0331451..4881d611c12 100644
--- a/compiler/rustc_middle/src/ty/significant_drop_order.rs
+++ b/compiler/rustc_middle/src/ty/significant_drop_order.rs
@@ -154,7 +154,7 @@ pub fn ty_dtor_span<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Span> {
             let dtor = if let Some(dtor) = tcx.adt_destructor(did) {
                 dtor.did
             } else if let Some(dtor) = tcx.adt_async_destructor(did) {
-                dtor.future
+                return Some(tcx.source_span(dtor.impl_did));
             } else {
                 return Some(try_local_did_span(did));
             };
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 68c6e02923a..e4863896fc8 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -455,26 +455,17 @@ impl<'tcx> TyCtxt<'tcx> {
                 continue;
             }
 
-            let [future, ctor] = self.associated_item_def_ids(impl_did) else {
-                self.dcx().span_delayed_bug(
-                    self.def_span(impl_did),
-                    "AsyncDrop impl without async_drop function or Dropper type",
-                );
-                continue;
-            };
-
-            if let Some((_, _, old_impl_did)) = dtor_candidate {
+            if let Some(old_impl_did) = dtor_candidate {
                 self.dcx()
                     .struct_span_err(self.def_span(impl_did), "multiple async drop impls found")
                     .with_span_note(self.def_span(old_impl_did), "other impl here")
                     .delay_as_bug();
             }
 
-            dtor_candidate = Some((*future, *ctor, impl_did));
+            dtor_candidate = Some(impl_did);
         }
 
-        let (future, ctor, _) = dtor_candidate?;
-        Some(ty::AsyncDestructor { future, ctor })
+        Some(ty::AsyncDestructor { impl_did: dtor_candidate? })
     }
 
     /// Returns async drop glue morphology for a definition. To get async drop