Fully remove rustc_middle::ich.

compiler/rustc_middle/src/ty/impls_ty.rs

@@ -0,0 +1,165 @@
+//! This module contains `HashStable` implementations for various data types
+//! from `rustc_middle::ty` in no particular order.
+
+use crate::middle::region;
+use crate::mir;
+use crate::ty;
+use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
+use rustc_query_system::ich::StableHashingContext;
+use std::cell::RefCell;
+use std::mem;
+
+impl<'a, 'tcx, T> HashStable<StableHashingContext<'a>> for &'tcx ty::List<T>
+where
+    T: HashStable<StableHashingContext<'a>>,
+{
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        thread_local! {
+            static CACHE: RefCell<FxHashMap<(usize, usize), Fingerprint>> =
+                RefCell::new(Default::default());
+        }
+
+        let hash = CACHE.with(|cache| {
+            let key = (self.as_ptr() as usize, self.len());
+            if let Some(&hash) = cache.borrow().get(&key) {
+                return hash;
+            }
+
+            let mut hasher = StableHasher::new();
+            (&self[..]).hash_stable(hcx, &mut hasher);
+
+            let hash: Fingerprint = hasher.finish();
+            cache.borrow_mut().insert(key, hash);
+            hash
+        });
+
+        hash.hash_stable(hcx, hasher);
+    }
+}
+
+impl<'a, 'tcx, T> ToStableHashKey<StableHashingContext<'a>> for &'tcx ty::List<T>
+where
+    T: HashStable<StableHashingContext<'a>>,
+{
+    type KeyType = Fingerprint;
+
+    #[inline]
+    fn to_stable_hash_key(&self, hcx: &StableHashingContext<'a>) -> Fingerprint {
+        let mut hasher = StableHasher::new();
+        let mut hcx: StableHashingContext<'a> = hcx.clone();
+        self.hash_stable(&mut hcx, &mut hasher);
+        hasher.finish()
+    }
+}
+
+impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::subst::GenericArg<'tcx> {
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        self.unpack().hash_stable(hcx, hasher);
+    }
+}
+
+impl<'a> HashStable<StableHashingContext<'a>> for ty::RegionKind {
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+        match *self {
+            ty::ReErased | ty::ReStatic => {
+                // No variant fields to hash for these ...
+            }
+            ty::ReEmpty(universe) => {
+                universe.hash_stable(hcx, hasher);
+            }
+            ty::ReLateBound(db, ty::BoundRegion { kind: ty::BrAnon(i), .. }) => {
+                db.hash_stable(hcx, hasher);
+                i.hash_stable(hcx, hasher);
+            }
+            ty::ReLateBound(db, ty::BoundRegion { kind: ty::BrNamed(def_id, name), .. }) => {
+                db.hash_stable(hcx, hasher);
+                def_id.hash_stable(hcx, hasher);
+                name.hash_stable(hcx, hasher);
+            }
+            ty::ReLateBound(db, ty::BoundRegion { kind: ty::BrEnv, .. }) => {
+                db.hash_stable(hcx, hasher);
+            }
+            ty::ReEarlyBound(ty::EarlyBoundRegion { def_id, index, name }) => {
+                def_id.hash_stable(hcx, hasher);
+                index.hash_stable(hcx, hasher);
+                name.hash_stable(hcx, hasher);
+            }
+            ty::ReFree(ref free_region) => {
+                free_region.hash_stable(hcx, hasher);
+            }
+            ty::RePlaceholder(p) => {
+                p.hash_stable(hcx, hasher);
+            }
+            ty::ReVar(..) => {
+                bug!("StableHasher: unexpected region {:?}", *self)
+            }
+        }
+    }
+}
+
+impl<'a> HashStable<StableHashingContext<'a>> for ty::RegionVid {
+    #[inline]
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        self.index().hash_stable(hcx, hasher);
+    }
+}
+
+impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::ConstVid<'tcx> {
+    #[inline]
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        self.index.hash_stable(hcx, hasher);
+    }
+}
+
+impl<'tcx> HashStable<StableHashingContext<'tcx>> for ty::BoundVar {
+    #[inline]
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'tcx>, hasher: &mut StableHasher) {
+        self.index().hash_stable(hcx, hasher);
+    }
+}
+
+impl<'a, 'tcx, T> HashStable<StableHashingContext<'a>> for ty::Binder<'tcx, T>
+where
+    T: HashStable<StableHashingContext<'a>>,
+{
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        self.as_ref().skip_binder().hash_stable(hcx, hasher);
+        self.bound_vars().hash_stable(hcx, hasher);
+    }
+}
+
+// AllocIds get resolved to whatever they point to (to be stable)
+impl<'a> HashStable<StableHashingContext<'a>> for mir::interpret::AllocId {
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        ty::tls::with_opt(|tcx| {
+            trace!("hashing {:?}", *self);
+            let tcx = tcx.expect("can't hash AllocIds during hir lowering");
+            tcx.get_global_alloc(*self).hash_stable(hcx, hasher);
+        });
+    }
+}
+
+// `Relocations` with default type parameters is a sorted map.
+impl<'a, Tag> HashStable<StableHashingContext<'a>> for mir::interpret::Relocations<Tag>
+where
+    Tag: HashStable<StableHashingContext<'a>>,
+{
+    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
+        self.len().hash_stable(hcx, hasher);
+        for reloc in self.iter() {
+            reloc.hash_stable(hcx, hasher);
+        }
+    }
+}
+
+impl<'a> ToStableHashKey<StableHashingContext<'a>> for region::Scope {
+    type KeyType = region::Scope;
+
+    #[inline]
+    fn to_stable_hash_key(&self, _: &StableHashingContext<'a>) -> region::Scope {
+        *self
+    }
+}