rustdoc: Collect traits in scope for lang items

2 files changed, 11 insertions, 8 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 87a88fbac71..66968c9ba54 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -1032,13 +1032,11 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     /// Iterates over the language items in the given crate.
-    fn get_lang_items(self, tcx: TyCtxt<'tcx>) -> &'tcx [(DefId, usize)] {
-        tcx.arena.alloc_from_iter(
-            self.root
-                .lang_items
-                .decode(self)
-                .map(|(def_index, index)| (self.local_def_id(def_index), index)),
-        )
+    fn get_lang_items(self) -> impl Iterator<Item = (DefId, usize)> + 'a {
+        self.root
+            .lang_items
+            .decode(self)
+            .map(move |(def_index, index)| (self.local_def_id(def_index), index))
     }
 
     /// Iterates over the diagnostic items in the given crate.
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 9b0272e7fd3..7708b5193f4 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -200,7 +200,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
         tcx.arena.alloc_slice(&result)
     }
     defined_lib_features => { cdata.get_lib_features(tcx) }
-    defined_lang_items => { cdata.get_lang_items(tcx) }
+    defined_lang_items => { tcx.arena.alloc_from_iter(cdata.get_lang_items()) }
     diagnostic_items => { cdata.get_diagnostic_items() }
     missing_lang_items => { cdata.get_missing_lang_items(tcx) }
 
@@ -501,6 +501,11 @@ impl CStore {
     ) -> impl Iterator<Item = (DefId, DefId)> + '_ {
         self.get_crate_data(cnum).get_inherent_impls()
     }
+
+    /// Decodes all lang items in the crate (for rustdoc).
+    pub fn lang_items_untracked(&self, cnum: CrateNum) -> impl Iterator<Item = DefId> + '_ {
+        self.get_crate_data(cnum).get_lang_items().map(|(def_id, _)| def_id)
+    }
 }
 
 impl CrateStore for CStore {