From a0f0a5f411d423ac4cb08a1b52ad3e93042d3c14 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Thu, 19 Jan 2023 16:09:10 +0000
Subject: [PATCH] Conditionally encode boolean

---
 .../rustc_metadata/src/rmeta/decoder/cstore_impl.rs    | 10 +++++++++-
 compiler/rustc_metadata/src/rmeta/encoder.rs           |  6 ++++--
 compiler/rustc_metadata/src/rmeta/mod.rs               |  3 ++-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index b09a739b14e66..c5d4da079c466 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -223,7 +223,15 @@ provide! { tcx, def_id, other, cdata,
     generator_kind => { table }
     trait_def => { table }
     deduced_param_attrs => { table }
-    is_type_alias_impl_trait => { table }
+    is_type_alias_impl_trait => {
+        debug_assert_eq!(tcx.def_kind(def_id), DefKind::OpaqueTy);
+        cdata
+            .root
+            .tables
+            .is_type_alias_impl_trait
+            .get(cdata, def_id.index)
+            .is_some()
+    }
     collect_trait_impl_trait_tys => {
         Ok(cdata
             .root
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 2cadc225d11ee..7304c891e9662 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1535,9 +1535,11 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             hir::ItemKind::Mod(ref m) => {
                 return self.encode_info_for_mod(item.owner_id.def_id, m);
             }
-            hir::ItemKind::OpaqueTy(..) => {
+            hir::ItemKind::OpaqueTy(ref opaque) => {
                 self.encode_explicit_item_bounds(def_id);
-                record!(self.tables.is_type_alias_impl_trait[def_id] <- self.tcx.is_type_alias_impl_trait(def_id));
+                if matches!(opaque.origin, hir::OpaqueTyOrigin::TyAlias) {
+                    self.tables.is_type_alias_impl_trait.set(def_id.index, ());
+                }
             }
             hir::ItemKind::Enum(..) => {
                 let adt_def = self.tcx.adt_def(def_id);
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 7fbc2e05fdadf..5718046442203 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -404,7 +404,8 @@ define_tables! {
     proc_macro: Table<DefIndex, MacroKind>,
     module_reexports: Table<DefIndex, LazyArray<ModChild>>,
     deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
-    is_type_alias_impl_trait: Table<DefIndex, LazyValue<bool>>,
+    // Slot is full when opaque is TAIT.
+    is_type_alias_impl_trait: Table<DefIndex, ()>,
 
     trait_impl_trait_tys: Table<DefIndex, LazyValue<FxHashMap<DefId, Ty<'static>>>>,
 }