Rollup merge of #89476 - cjgillot:expn-id, r=petrochenkov

Correct decoding of foreign expansions during incr. comp.

Fixes https://github.com/rust-lang/rust/issues/74946

The original issue was due to a wrong assertion in `expn_hash_to_expn_id`.

The secondary issue was due to a mismatch between the encoding and decoding paths for expansions that are created after the TyCtxt is created.

2 files changed, 10 insertions, 6 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index c7d0f594f01..89bb5797a82 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -1632,7 +1632,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         self.def_path_hash_map.def_path_hash_to_def_index(&hash)
     }
 
-    fn expn_hash_to_expn_id(&self, index_guess: u32, hash: ExpnHash) -> ExpnId {
+    fn expn_hash_to_expn_id(&self, sess: &Session, index_guess: u32, hash: ExpnHash) -> ExpnId {
         debug_assert_eq!(ExpnId::from_hash(hash), None);
         let index_guess = ExpnIndex::from_u32(index_guess);
         let old_hash = self.root.expn_hashes.get(self, index_guess).map(|lazy| lazy.decode(self));
@@ -1654,8 +1654,6 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                     let i = ExpnIndex::from_u32(i);
                     if let Some(hash) = self.root.expn_hashes.get(self, i) {
                         map.insert(hash.decode(self), i);
-                    } else {
-                        panic!("Missing expn_hash entry for {:?}", i);
                     }
                 }
                 map
@@ -1663,7 +1661,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             map[&hash]
         };
 
-        let data = self.root.expn_data.get(self, index).unwrap().decode(self);
+        let data = self.root.expn_data.get(self, index).unwrap().decode((self, sess));
         rustc_span::hygiene::register_expn_id(self.cnum, index, data, hash)
     }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 292ef03d856..4e7f85d2c37 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -506,7 +506,13 @@ impl CrateStore for CStore {
         DefId { krate: cnum, index: def_index }
     }
 
-    fn expn_hash_to_expn_id(&self, cnum: CrateNum, index_guess: u32, hash: ExpnHash) -> ExpnId {
-        self.get_crate_data(cnum).expn_hash_to_expn_id(index_guess, hash)
+    fn expn_hash_to_expn_id(
+        &self,
+        sess: &Session,
+        cnum: CrateNum,
+        index_guess: u32,
+        hash: ExpnHash,
+    ) -> ExpnId {
+        self.get_crate_data(cnum).expn_hash_to_expn_id(sess, index_guess, hash)
     }
 }