Remove unused hashing infra.

Author: cjgillot

compiler/rustc_ast_lowering/src/lib.rs

@@ -631,14 +631,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     ) -> (Fingerprint, Fingerprint) {
         self.tcx.with_stable_hashing_context(|mut hcx| {
             let mut stable_hasher = StableHasher::new();
-            hcx.with_hir_bodies(true, node.def_id(), bodies, |hcx| {
+            hcx.with_hir_bodies(node.def_id(), bodies, |hcx| {
                 node.hash_stable(hcx, &mut stable_hasher)
             });
             let hash_including_bodies = stable_hasher.finish();
             let mut stable_hasher = StableHasher::new();
-            hcx.with_hir_bodies(false, node.def_id(), bodies, |hcx| {
-                node.hash_stable(hcx, &mut stable_hasher)
-            });
+            hcx.without_hir_bodies(|hcx| node.hash_stable(hcx, &mut stable_hasher));
             let hash_without_bodies = stable_hasher.finish();
             (hash_including_bodies, hash_without_bodies)
         })

compiler/rustc_query_system/src/ich/hcx.rs

@@ -40,11 +40,8 @@ pub struct StableHashingContext<'a> {
 #[derive(Clone, Copy)]
 pub(super) enum BodyResolver<'tcx> {
     Forbidden,
-    Traverse {
-        hash_bodies: bool,
-        owner: LocalDefId,
-        bodies: &'tcx SortedMap<hir::ItemLocalId, &'tcx hir::Body<'tcx>>,
-    },
+    Ignore,
+    Traverse { owner: LocalDefId, bodies: &'tcx SortedMap<hir::ItemLocalId, &'tcx hir::Body<'tcx>> },
 }
 
 impl<'a> StableHashingContext<'a> {
@@ -98,32 +95,20 @@ impl<'a> StableHashingContext<'a> {
         Self::new_with_or_without_spans(sess, definitions, cstore, source_span, always_ignore_spans)
     }
 
-    /// Allow hashing
     #[inline]
-    pub fn while_hashing_hir_bodies(&mut self, hb: bool, f: impl FnOnce(&mut Self)) {
-        let prev = match &mut self.body_resolver {
-            BodyResolver::Forbidden => panic!("Hashing HIR bodies is forbidden."),
-            BodyResolver::Traverse { ref mut hash_bodies, .. } => {
-                std::mem::replace(hash_bodies, hb)
-            }
-        };
-        f(self);
-        match &mut self.body_resolver {
-            BodyResolver::Forbidden => unreachable!(),
-            BodyResolver::Traverse { ref mut hash_bodies, .. } => *hash_bodies = prev,
-        }
+    pub fn without_hir_bodies(&mut self, f: impl FnOnce(&mut StableHashingContext<'_>)) {
+        f(&mut StableHashingContext { body_resolver: BodyResolver::Ignore, ..self.clone() });
     }
 
     #[inline]
     pub fn with_hir_bodies(
         &mut self,
-        hash_bodies: bool,
         owner: LocalDefId,
         bodies: &SortedMap<hir::ItemLocalId, &hir::Body<'_>>,
         f: impl FnOnce(&mut StableHashingContext<'_>),
     ) {
         f(&mut StableHashingContext {
-            body_resolver: BodyResolver::Traverse { hash_bodies, owner, bodies },
+            body_resolver: BodyResolver::Traverse { owner, bodies },
             ..self.clone()
         });
     }

compiler/rustc_query_system/src/ich/impls_hir.rs

@@ -12,8 +12,8 @@ impl<'ctx> rustc_hir::HashStableContext for StableHashingContext<'ctx> {
         let hcx = self;
         match hcx.body_resolver {
             BodyResolver::Forbidden => panic!("Hashing HIR bodies is forbidden."),
-            BodyResolver::Traverse { hash_bodies: false, .. } => {}
-            BodyResolver::Traverse { hash_bodies: true, owner, bodies } => {
+            BodyResolver::Ignore => {}
+            BodyResolver::Traverse { owner, bodies } => {
                 assert_eq!(id.hir_id.owner, owner);
                 bodies[&id.hir_id.local_id].hash_stable(hcx, hasher);
             }