Rollup merge of #41135 - japaric:unstable-docs, r=steveklabnik

[rust.git] / src / librustc / ty / util.rs

diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index fd95724990941337035ec75a3614b20479051044..fd8191303a9a60cb92e9f1bb9bd1340daba448f5 100644 (file)
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -13,7 +13,7 @@
 use hir::def_id::{DefId, LOCAL_CRATE};
 use hir::map::DefPathData;
 use infer::InferCtxt;
-use hir::map as hir_map;
+// use hir::map as hir_map;
 use traits::{self, Reveal};
 use ty::{self, Ty, TyCtxt, TypeAndMut, TypeFlags, TypeFoldable};
 use ty::ParameterEnvironment;
@@ -398,6 +398,16 @@ pub fn closure_base_def_id(&self, def_id: DefId) -> DefId {
         }
         def_id
     }
+
+    /// Given the def-id of some item that has no type parameters, make
+    /// a suitable "empty substs" for it.
+    pub fn empty_substs_for_def_id(self, item_def_id: DefId) -> &'tcx ty::Substs<'tcx> {
+        ty::Substs::for_item(self, item_def_id,
+                             |_, _| self.mk_region(ty::ReErased),
+                             |_, _| {
+            bug!("empty_substs_for_def_id: {:?} has type parameters", item_def_id)
+        })
+    }
 }
 
 pub struct TypeIdHasher<'a, 'gcx: 'a+'tcx, 'tcx: 'a, W> {
@@ -431,13 +441,11 @@ fn hash_discriminant_u8<T>(&mut self, x: &T) {
 
     fn def_id(&mut self, did: DefId) {
         // Hash the DefPath corresponding to the DefId, which is independent
-        // of compiler internal state.
-        let path = self.tcx.def_path(did);
-        self.def_path(&path)
-    }
-
-    pub fn def_path(&mut self, def_path: &hir_map::DefPath) {
-        def_path.deterministic_hash_to(self.tcx, &mut self.state);
+        // of compiler internal state. We already have a stable hash value of
+        // all DefPaths available via tcx.def_path_hash(), so we just feed that
+        // into the hasher.
+        let hash = self.tcx.def_path_hash(did);
+        self.hash(hash);
     }
 }
 
@@ -499,18 +507,21 @@ fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
     }
 
     fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+        self.hash_discriminant_u8(r);
         match *r {
-            ty::ReErased => {
-                self.hash::<u32>(0);
+            ty::ReErased |
+            ty::ReStatic |
+            ty::ReEmpty => {
+                // No variant fields to hash for these ...
             }
             ty::ReLateBound(db, ty::BrAnon(i)) => {
-                assert!(db.depth > 0);
-                self.hash::<u32>(db.depth);
+                self.hash(db.depth);
                 self.hash(i);
             }
-            ty::ReStatic |
-            ty::ReEmpty |
-            ty::ReEarlyBound(..) |
+            ty::ReEarlyBound(ty::EarlyBoundRegion { index, name }) => {
+                self.hash(index);
+                self.hash(name.as_str());
+            }
             ty::ReLateBound(..) |
             ty::ReFree(..) |
             ty::ReScope(..) |