Rollup merge of #144822 - Zalathar:hash-owner-nodes, r=compiler-errors

Return a struct with named fields from `hash_owner_nodes`
While looking through this code for other reasons, I noticed a nice opportunity to return a struct with named fields instead of a tuple. The first patch also introduces an early-return to flatten the rest of `hash_owner_nodes`.
There are further changes that could potentially be made here (renaming things, `Option<Hashes>` instead of optional fields), but I'm not deeply familiar with this code so I didn't want to disturb the calling code too much.

Author: samueltardieu

compiler/rustc_ast_lowering/src/lib.rs

@@ -675,7 +675,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 let bodies = SortedMap::from_presorted_elements(bodies);
 
 // Don't hash unless necessary, because it's expensive.
-let(opt_hash_including_bodies, attrs_hash, delayed_lints_hash) =
+letrustc_middle::hir::Hashes{opt_hash_including_bodies, attrs_hash, delayed_lints_hash} =
 self.tcx.hash_owner_nodes(node,&bodies,&attrs,&delayed_lints, define_opaque);
 let num_nodes = self.item_local_id_counter.as_usize();
 let(nodes, parenting) = index::index_hir(self.tcx, node,&bodies, num_nodes);

compiler/rustc_middle/src/hir/mod.rs

@@ -174,36 +174,52 @@ impl<'tcx> TyCtxt<'tcx> {
 attrs:&SortedMap<ItemLocalId,&[Attribute]>,
 delayed_lints:&[DelayedLint],
 define_opaque:Option<&[(Span,LocalDefId)]>,
-) -> (Option<Fingerprint>,Option<Fingerprint>,Option<Fingerprint>){
-ifself.needs_crate_hash(){
-self.with_stable_hashing_context(|mut hcx| {
-letmut stable_hasher = StableHasher::new();
- node.hash_stable(&mut hcx,&mut stable_hasher);
-// Bodies are stored out of line, so we need to pull them explicitly in the hash.
- bodies.hash_stable(&mut hcx,&mut stable_hasher);
-let h1 = stable_hasher.finish();
-
-letmut stable_hasher = StableHasher::new();
- attrs.hash_stable(&mut hcx,&mut stable_hasher);
-
-// Hash the defined opaque types, which are not present in the attrs.
- define_opaque.hash_stable(&mut hcx,&mut stable_hasher);
-
-let h2 = stable_hasher.finish();
-
-// hash lints emitted during ast lowering
-letmut stable_hasher = StableHasher::new();
- delayed_lints.hash_stable(&mut hcx,&mut stable_hasher);
-let h3 = stable_hasher.finish();
-
-(Some(h1),Some(h2),Some(h3))
-})
-}else{
-(None,None,None)
+) -> Hashes{
+if !self.needs_crate_hash(){
+returnHashes{
+opt_hash_including_bodies:None,
+attrs_hash:None,
+delayed_lints_hash:None,
+};
 }
+
+self.with_stable_hashing_context(|mut hcx| {
+letmut stable_hasher = StableHasher::new();
+ node.hash_stable(&mut hcx,&mut stable_hasher);
+// Bodies are stored out of line, so we need to pull them explicitly in the hash.
+ bodies.hash_stable(&mut hcx,&mut stable_hasher);
+let h1 = stable_hasher.finish();
+
+letmut stable_hasher = StableHasher::new();
+ attrs.hash_stable(&mut hcx,&mut stable_hasher);
+
+// Hash the defined opaque types, which are not present in the attrs.
+ define_opaque.hash_stable(&mut hcx,&mut stable_hasher);
+
+let h2 = stable_hasher.finish();
+
+// hash lints emitted during ast lowering
+letmut stable_hasher = StableHasher::new();
+ delayed_lints.hash_stable(&mut hcx,&mut stable_hasher);
+let h3 = stable_hasher.finish();
+
+Hashes{
+opt_hash_including_bodies:Some(h1),
+attrs_hash:Some(h2),
+delayed_lints_hash:Some(h3),
+}
+})
 }
 }
 
+/// Hashes computed by [`TyCtxt::hash_owner_nodes`] if necessary.
+#[derive(Clone,Copy,Debug)]
+pubstructHashes{
+pubopt_hash_including_bodies:Option<Fingerprint>,
+pubattrs_hash:Option<Fingerprint>,
+pubdelayed_lints_hash:Option<Fingerprint>,
+}
+
 pubfnprovide(providers:&mutProviders){
  providers.hir_crate_items = map::hir_crate_items;
  providers.crate_hash = map::crate_hash;

compiler/rustc_middle/src/ty/context.rs

@@ -1381,7 +1381,7 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
 let bodies = Default::default();
 let attrs = hir::AttributeMap::EMPTY;
 
-let(opt_hash_including_bodies,_, _) =
+letrustc_middle::hir::Hashes{opt_hash_including_bodies,.. } =
 self.tcx.hash_owner_nodes(node,&bodies,&attrs.map,&[], attrs.define_opaque);
 let node = node.into();
 self.opt_hir_owner_nodes(Some(self.tcx.arena.alloc(hir::OwnerNodes{