Remove the DefPathHash from the HIR hash

Author: Daniel-B-Smith

compiler/rustc_ast_lowering/src/lib.rs

@@ -506,17 +506,12 @@ fn index_crate<'a, 'b>(
 
 /// Compute the hash for the HIR of the full crate.
 /// This hash will then be part of the crate_hash which is stored in the metadata.
-fn compute_hir_hash(
-    tcx: TyCtxt<'_>,
-    owners: &IndexSlice<LocalDefId, hir::MaybeOwner<'_>>,
-) -> Fingerprint {
+fn compute_hir_hash(owners: &IndexSlice<LocalDefId, hir::MaybeOwner<'_>>) -> Fingerprint {
     owners
         .iter_enumerated()
-        .filter_map(|(def_id, info)| {
+        .filter_map(|(_, info)| {
             let info = info.as_owner()?;
-            let dph = tcx.hir_def_path_hash(def_id).0;
-            let info_finger = info.fingerprint();
-            Some(dph.combine(info_finger))
+            Some(info.fingerprint())
         })
         .reduce(Fingerprint::combine_commutative)
         .expect("HIR hash requested without any content")
@@ -556,8 +551,7 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> mid_hir::Crate<'_> {
     }
 
     // Don't hash unless necessary, because it's expensive.
-    let opt_hir_hash =
-        if tcx.needs_hir_hash() { Some(compute_hir_hash(tcx, &owners)) } else { None };
+    let opt_hir_hash = if tcx.needs_hir_hash() { Some(compute_hir_hash(&owners)) } else { None };
 
     let delayed_resolver = Steal::new((resolver, krate));
     mid_hir::Crate::new(owners, delayed_ids, delayed_resolver, opt_hir_hash)