intern CodeExtents

Make a `CodeExtent<'tcx>` be something allocated in an arena
instead of an index into the `RegionMaps`.

src/librustc/cfg/construct.rs

@@ -583,10 +583,10 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                         scope_id: ast::NodeId,
                         to_index: CFGIndex) {
         let mut data = CFGEdgeData { exiting_scopes: vec![] };
-        let mut scope = self.tcx.region_maps().node_extent(from_expr.id);
-        let target_scope = self.tcx.region_maps().node_extent(scope_id);
+        let mut scope = self.tcx.node_extent(from_expr.id);
+        let target_scope = self.tcx.node_extent(scope_id);
         while scope != target_scope {
-            data.exiting_scopes.push(scope.node_id(&self.tcx.region_maps()));
+            data.exiting_scopes.push(scope.node_id());
             scope = self.tcx.region_maps().encl_scope(scope);
         }
         self.graph.add_edge(from_index, to_index, data);

src/librustc/ich/impls_ty.rs

@@ -39,7 +39,7 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::subst::Kind<'t
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::Region {
+impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::RegionKind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
                                           hcx: &mut StableHashingContext<'a, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
@@ -432,17 +432,6 @@ impl_stable_hash_for!(enum ty::cast::CastKind {
     FnPtrAddrCast
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::middle::region::CodeExtent
-{
-    fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
-                                          hasher: &mut StableHasher<W>) {
-        hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| {
-            hcx.tcx().region_maps().code_extent_data(*self).hash_stable(hcx, hasher);
-        });
-    }
-}
-
 impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::middle::region::CodeExtentData
 {
     fn hash_stable<W: StableHasherResult>(&self,
@@ -477,7 +466,7 @@ impl_stable_hash_for!(struct ty::adjustment::CoerceUnsizedInfo {
     custom_kind
 });
 
-impl_stable_hash_for!(struct ty::FreeRegion {
+impl_stable_hash_for!(struct ty::FreeRegion<'tcx> {
     scope,
     bound_region
 });

src/librustc/infer/combine.rs

@@ -315,7 +315,7 @@ impl<'cx, 'gcx, 'tcx> ty::fold::TypeFolder<'gcx, 'tcx> for Generalizer<'cx, 'gcx
         }
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             // Never make variables for regions bound within the type itself,
             // nor for erased regions.

src/librustc/infer/equate.rs

@@ -78,8 +78,8 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
         }
     }
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region> {
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})",
                self.tag(),
                a,

src/librustc/infer/error_reporting/mod.rs

@@ -79,7 +79,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn note_and_explain_region(self,
                                    err: &mut DiagnosticBuilder,
                                    prefix: &str,
-                                   region: &'tcx ty::Region,
+                                   region: ty::Region<'tcx>,
                                    suffix: &str) {
         fn item_scope_tag(item: &hir::Item) -> &'static str {
             match item.node {
@@ -124,14 +124,14 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                     format!("{}unknown scope: {:?}{}.  Please report a bug.",
                             prefix, scope, suffix)
                 };
-                let span = match scope.span(&self.region_maps(), &self.hir) {
+                let span = match scope.span(&self.hir) {
                     Some(s) => s,
                     None => {
                         err.note(&unknown_scope());
                         return;
                     }
                 };
-                let tag = match self.hir.find(scope.node_id(&self.region_maps())) {
+                let tag = match self.hir.find(scope.node_id()) {
                     Some(hir_map::NodeBlock(_)) => "block",
                     Some(hir_map::NodeExpr(expr)) => match expr.node {
                         hir::ExprCall(..) => "call",
@@ -151,7 +151,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                         return;
                     }
                 };
-                let scope_decorated_tag = match self.region_maps().code_extent_data(scope) {
+                let scope_decorated_tag = match *scope {
                     region::CodeExtentData::Misc(_) => tag,
                     region::CodeExtentData::CallSiteScope { .. } => {
                         "scope of call-site for function"
@@ -184,7 +184,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                     }
                 };
 
-                let node = fr.scope.map(|s| s.node_id(&self.region_maps()))
+                let node = fr.scope.map(|s| s.node_id())
                                    .unwrap_or(DUMMY_NODE_ID);
                 let unknown;
                 let tag = match self.hir.find(node) {
@@ -517,7 +517,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                         values.1.push_normal("<");
                     }
 
-                    fn lifetime_display(lifetime: &Region) -> String {
+                    fn lifetime_display(lifetime: Region) -> String {
                         let s = format!("{}", lifetime);
                         if s.is_empty() {
                             "'_".to_string()
@@ -769,7 +769,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     fn report_generic_bound_failure(&self,
                                     origin: SubregionOrigin<'tcx>,
                                     bound_kind: GenericKind<'tcx>,
-                                    sub: &'tcx Region)
+                                    sub: Region<'tcx>)
     {
         // FIXME: it would be better to report the first error message
         // with the span of the parameter itself, rather than the span
@@ -848,9 +848,9 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     fn report_sub_sup_conflict(&self,
                                var_origin: RegionVariableOrigin,
                                sub_origin: SubregionOrigin<'tcx>,
-                               sub_region: &'tcx Region,
+                               sub_region: Region<'tcx>,
                                sup_origin: SubregionOrigin<'tcx>,
-                               sup_region: &'tcx Region) {
+                               sup_region: Region<'tcx>) {
         let mut err = self.report_inference_failure(var_origin);
 
         self.tcx.note_and_explain_region(&mut err,

src/librustc/infer/error_reporting/note.rs

@@ -146,8 +146,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     pub(super) fn report_concrete_failure(&self,
                                           origin: SubregionOrigin<'tcx>,
-                                          sub: &'tcx Region,
-                                          sup: &'tcx Region)
+                                          sub: Region<'tcx>,
+                                          sup: Region<'tcx>)
                                           -> DiagnosticBuilder<'tcx> {
         match origin {
             infer::Subtype(trace) => {

src/librustc/infer/freshen.rs

@@ -83,7 +83,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for TypeFreshener<'a, 'gcx, 'tcx> {
         self.infcx.tcx
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReEarlyBound(..) |
             ty::ReLateBound(..) => {

src/librustc/infer/fudge.rs

@@ -147,7 +147,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionFudger<'a, 'gcx, 'tcx> {
         }
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReVar(v) if self.region_vars.contains(&v) => {
                 self.infcx.next_region_var(self.origin.clone())

src/librustc/infer/glb.rs

@@ -59,8 +59,8 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
         lattice::super_lattice_tys(self, a, b)
     }
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region> {
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})",
                self.tag(),
                a,

src/librustc/infer/higher_ranked/mod.rs

@@ -269,9 +269,9 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
                                              snapshot: &CombinedSnapshot,
                                              debruijn: ty::DebruijnIndex,
                                              new_vars: &[ty::RegionVid],
-                                             a_map: &FxHashMap<ty::BoundRegion, &'tcx ty::Region>,
-                                             r0: &'tcx ty::Region)
-                                             -> &'tcx ty::Region {
+                                             a_map: &FxHashMap<ty::BoundRegion, ty::Region<'tcx>>,
+                                             r0: ty::Region<'tcx>)
+                                             -> ty::Region<'tcx> {
             // Regions that pre-dated the LUB computation stay as they are.
             if !is_var_in_set(new_vars, r0) {
                 assert!(!r0.is_bound());
@@ -284,7 +284,7 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
             // Variables created during LUB computation which are
             // *related* to regions that pre-date the LUB computation
             // stay as they are.
-            if !tainted.iter().all(|r| is_var_in_set(new_vars, *r)) {
+            if !tainted.iter().all(|&r| is_var_in_set(new_vars, r)) {
                 debug!("generalize_region(r0={:?}): \
                         non-new-variables found in {:?}",
                        r0, tainted);
@@ -365,11 +365,11 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
                                              snapshot: &CombinedSnapshot,
                                              debruijn: ty::DebruijnIndex,
                                              new_vars: &[ty::RegionVid],
-                                             a_map: &FxHashMap<ty::BoundRegion, &'tcx ty::Region>,
+                                             a_map: &FxHashMap<ty::BoundRegion, ty::Region<'tcx>>,
                                              a_vars: &[ty::RegionVid],
                                              b_vars: &[ty::RegionVid],
-                                             r0: &'tcx ty::Region)
-                                             -> &'tcx ty::Region {
+                                             r0: ty::Region<'tcx>)
+                                             -> ty::Region<'tcx> {
             if !is_var_in_set(new_vars, r0) {
                 assert!(!r0.is_bound());
                 return r0;
@@ -434,8 +434,8 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
 
         fn rev_lookup<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
                                       span: Span,
-                                      a_map: &FxHashMap<ty::BoundRegion, &'tcx ty::Region>,
-                                      r: &'tcx ty::Region) -> &'tcx ty::Region
+                                      a_map: &FxHashMap<ty::BoundRegion, ty::Region<'tcx>>,
+                                      r: ty::Region<'tcx>) -> ty::Region<'tcx>
         {
             for (a_br, a_r) in a_map {
                 if *a_r == r {
@@ -450,14 +450,14 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
 
         fn fresh_bound_variable<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
                                                 debruijn: ty::DebruijnIndex)
-                                                -> &'tcx ty::Region {
+                                                -> ty::Region<'tcx> {
             infcx.region_vars.new_bound(debruijn)
         }
     }
 }
 
 fn var_ids<'a, 'gcx, 'tcx>(fields: &CombineFields<'a, 'gcx, 'tcx>,
-                           map: &FxHashMap<ty::BoundRegion, &'tcx ty::Region>)
+                           map: &FxHashMap<ty::BoundRegion, ty::Region<'tcx>>)
                            -> Vec<ty::RegionVid> {
     map.iter()
        .map(|(_, &r)| match *r {
@@ -472,7 +472,7 @@ fn var_ids<'a, 'gcx, 'tcx>(fields: &CombineFields<'a, 'gcx, 'tcx>,
        .collect()
 }
 
-fn is_var_in_set(new_vars: &[ty::RegionVid], r: &ty::Region) -> bool {
+fn is_var_in_set(new_vars: &[ty::RegionVid], r: ty::Region) -> bool {
     match *r {
         ty::ReVar(ref v) => new_vars.iter().any(|x| x == v),
         _ => false
@@ -484,7 +484,7 @@ fn fold_regions_in<'a, 'gcx, 'tcx, T, F>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                                          mut fldr: F)
                                          -> T
     where T: TypeFoldable<'tcx>,
-          F: FnMut(&'tcx ty::Region, ty::DebruijnIndex) -> &'tcx ty::Region,
+          F: FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
 {
     tcx.fold_regions(unbound_value, &mut false, |region, current_depth| {
         // we should only be encountering "escaping" late-bound regions here,
@@ -502,9 +502,9 @@ fn fold_regions_in<'a, 'gcx, 'tcx, T, F>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     fn tainted_regions(&self,
                        snapshot: &CombinedSnapshot,
-                       r: &'tcx ty::Region,
+                       r: ty::Region<'tcx>,
                        directions: TaintDirections)
-                       -> FxHashSet<&'tcx ty::Region> {
+                       -> FxHashSet<ty::Region<'tcx>> {
         self.region_vars.tainted(&snapshot.region_vars_snapshot, r, directions)
     }
 
@@ -731,7 +731,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         // region back to the `ty::BoundRegion` that it originally
         // represented. Because `leak_check` passed, we know that
         // these taint sets are mutually disjoint.
-        let inv_skol_map: FxHashMap<&'tcx ty::Region, ty::BoundRegion> =
+        let inv_skol_map: FxHashMap<ty::Region<'tcx>, ty::BoundRegion> =
             skol_map
             .iter()
             .flat_map(|(&skol_br, &skol)| {

src/librustc/infer/lub.rs

@@ -59,8 +59,8 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
         lattice::super_lattice_tys(self, a, b)
     }
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region> {
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})",
                self.tag(),
                a,

src/librustc/infer/mod.rs

@@ -205,7 +205,7 @@ pub struct InferCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
 
 /// A map returned by `skolemize_late_bound_regions()` indicating the skolemized
 /// region that each late-bound region was replaced with.
-pub type SkolemizationMap<'tcx> = FxHashMap<ty::BoundRegion, &'tcx ty::Region>;
+pub type SkolemizationMap<'tcx> = FxHashMap<ty::BoundRegion, ty::Region<'tcx>>;
 
 /// See `error_reporting` module for more details
 #[derive(Clone, Debug)]
@@ -1008,7 +1008,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn add_given(&self,
-                     sub: ty::FreeRegion,
+                     sub: ty::FreeRegion<'tcx>,
                      sup: ty::RegionVid)
     {
         self.region_vars.add_given(sub, sup);
@@ -1107,8 +1107,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     pub fn sub_regions(&self,
                        origin: SubregionOrigin<'tcx>,
-                       a: &'tcx ty::Region,
-                       b: &'tcx ty::Region) {
+                       a: ty::Region<'tcx>,
+                       b: ty::Region<'tcx>) {
         debug!("sub_regions({:?} <: {:?})", a, b);
         self.region_vars.make_subregion(origin, a, b);
     }
@@ -1210,7 +1210,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn next_region_var(&self, origin: RegionVariableOrigin)
-                           -> &'tcx ty::Region {
+                           -> ty::Region<'tcx> {
         self.tcx.mk_region(ty::ReVar(self.region_vars.new_region_var(origin)))
     }
 
@@ -1219,7 +1219,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     pub fn region_var_for_def(&self,
                               span: Span,
                               def: &ty::RegionParameterDef)
-                              -> &'tcx ty::Region {
+                              -> ty::Region<'tcx> {
         self.next_region_var(EarlyBoundRegion(span, def.name, def.issue_32330))
     }
 
@@ -1270,7 +1270,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         })
     }
 
-    pub fn fresh_bound_region(&self, debruijn: ty::DebruijnIndex) -> &'tcx ty::Region {
+    pub fn fresh_bound_region(&self, debruijn: ty::DebruijnIndex) -> ty::Region<'tcx> {
         self.region_vars.new_bound(debruijn)
     }
 
@@ -1322,7 +1322,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn resolve_regions_and_report_errors(&self,
-                                             free_regions: &FreeRegionMap,
+                                             free_regions: &FreeRegionMap<'tcx>,
                                              subject_node_id: ast::NodeId) {
         let errors = self.region_vars.resolve_regions(free_regions, subject_node_id);
         if !self.is_tainted_by_errors() {
@@ -1531,7 +1531,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         span: Span,
         lbrct: LateBoundRegionConversionTime,
         value: &ty::Binder<T>)
-        -> (T, FxHashMap<ty::BoundRegion, &'tcx ty::Region>)
+        -> (T, FxHashMap<ty::BoundRegion, ty::Region<'tcx>>)
         where T : TypeFoldable<'tcx>
     {
         self.tcx.replace_late_bound_regions(
@@ -1577,7 +1577,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     pub fn verify_generic_bound(&self,
                                 origin: SubregionOrigin<'tcx>,
                                 kind: GenericKind<'tcx>,
-                                a: &'tcx ty::Region,
+                                a: ty::Region<'tcx>,
                                 bound: VerifyBound<'tcx>) {
         debug!("verify_generic_bound({:?}, {:?} <: {:?})",
                kind,

src/librustc/infer/region_inference/graphviz.rs

@@ -123,20 +123,20 @@ struct ConstraintGraph<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
     graph_name: String,
     map: &'a FxHashMap<Constraint<'tcx>, SubregionOrigin<'tcx>>,
-    node_ids: FxHashMap<Node, usize>,
+    node_ids: FxHashMap<Node<'tcx>, usize>,
 }
 
 #[derive(Clone, Hash, PartialEq, Eq, Debug, Copy)]
-enum Node {
+enum Node<'tcx> {
     RegionVid(ty::RegionVid),
-    Region(ty::Region),
+    Region(ty::RegionKind<'tcx>),
 }
 
 // type Edge = Constraint;
 #[derive(Clone, PartialEq, Eq, Debug, Copy)]
 enum Edge<'tcx> {
     Constraint(Constraint<'tcx>),
-    EnclScope(CodeExtent, CodeExtent),
+    EnclScope(CodeExtent<'tcx>, CodeExtent<'tcx>),
 }
 
 impl<'a, 'gcx, 'tcx> ConstraintGraph<'a, 'gcx, 'tcx> {
@@ -160,8 +160,8 @@ impl<'a, 'gcx, 'tcx> ConstraintGraph<'a, 'gcx, 'tcx> {
             }
 
             tcx.region_maps().each_encl_scope(|sub, sup| {
-                add_node(Node::Region(ty::ReScope(*sub)));
-                add_node(Node::Region(ty::ReScope(*sup)));
+                add_node(Node::Region(ty::ReScope(sub)));
+                add_node(Node::Region(ty::ReScope(sup)));
             });
         }
 
@@ -175,7 +175,7 @@ impl<'a, 'gcx, 'tcx> ConstraintGraph<'a, 'gcx, 'tcx> {
 }
 
 impl<'a, 'gcx, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
-    type Node = Node;
+    type Node = Node<'tcx>;
     type Edge = Edge<'tcx>;
     fn graph_id(&self) -> dot::Id {
         dot::Id::new(&*self.graph_name).unwrap()
@@ -208,7 +208,7 @@ impl<'a, 'gcx, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
     }
 }
 
-fn constraint_to_nodes(c: &Constraint) -> (Node, Node) {
+fn constraint_to_nodes<'tcx>(c: &Constraint<'tcx>) -> (Node<'tcx>, Node<'tcx>) {
     match *c {
         Constraint::ConstrainVarSubVar(rv_1, rv_2) =>
             (Node::RegionVid(rv_1), Node::RegionVid(rv_2)),
@@ -221,7 +221,7 @@ fn constraint_to_nodes(c: &Constraint) -> (Node, Node) {
     }
 }
 
-fn edge_to_nodes(e: &Edge) -> (Node, Node) {
+fn edge_to_nodes<'tcx>(e: &Edge<'tcx>) -> (Node<'tcx>, Node<'tcx>) {
     match *e {
         Edge::Constraint(ref c) => constraint_to_nodes(c),
         Edge::EnclScope(sub, sup) => {
@@ -232,9 +232,9 @@ fn edge_to_nodes(e: &Edge) -> (Node, Node) {
 }
 
 impl<'a, 'gcx, 'tcx> dot::GraphWalk<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
-    type Node = Node;
+    type Node = Node<'tcx>;
     type Edge = Edge<'tcx>;
-    fn nodes(&self) -> dot::Nodes<Node> {
+    fn nodes(&self) -> dot::Nodes<Node<'tcx>> {
         let mut set = FxHashSet();
         for node in self.node_ids.keys() {
             set.insert(*node);
@@ -245,16 +245,16 @@ impl<'a, 'gcx, 'tcx> dot::GraphWalk<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
     fn edges(&self) -> dot::Edges<Edge<'tcx>> {
         debug!("constraint graph has {} edges", self.map.len());
         let mut v: Vec<_> = self.map.keys().map(|e| Edge::Constraint(*e)).collect();
-        self.tcx.region_maps().each_encl_scope(|sub, sup| v.push(Edge::EnclScope(*sub, *sup)));
+        self.tcx.region_maps().each_encl_scope(|sub, sup| v.push(Edge::EnclScope(sub, sup)));
         debug!("region graph has {} edges", v.len());
         Cow::Owned(v)
     }
-    fn source(&self, edge: &Edge<'tcx>) -> Node {
+    fn source(&self, edge: &Edge<'tcx>) -> Node<'tcx> {
         let (n1, _) = edge_to_nodes(edge);
         debug!("edge {:?} has source {:?}", edge, n1);
         n1
     }
-    fn target(&self, edge: &Edge<'tcx>) -> Node {
+    fn target(&self, edge: &Edge<'tcx>) -> Node<'tcx> {
         let (_, n2) = edge_to_nodes(edge);
         debug!("edge {:?} has target {:?}", edge, n2);
         n2

src/librustc/infer/region_inference/mod.rs

@@ -44,17 +44,17 @@ pub enum Constraint<'tcx> {
     ConstrainVarSubVar(RegionVid, RegionVid),
 
     // Concrete region is subregion of region variable
-    ConstrainRegSubVar(&'tcx Region, RegionVid),
+    ConstrainRegSubVar(Region<'tcx>, RegionVid),
 
     // Region variable is subregion of concrete region. This does not
     // directly affect inference, but instead is checked after
     // inference is complete.
-    ConstrainVarSubReg(RegionVid, &'tcx Region),
+    ConstrainVarSubReg(RegionVid, Region<'tcx>),
 
     // A constraint where neither side is a variable. This does not
     // directly affect inference, but instead is checked after
     // inference is complete.
-    ConstrainRegSubReg(&'tcx Region, &'tcx Region),
+    ConstrainRegSubReg(Region<'tcx>, Region<'tcx>),
 }
 
 // VerifyGenericBound(T, _, R, RS): The parameter type `T` (or
@@ -66,7 +66,7 @@ pub enum Constraint<'tcx> {
 pub struct Verify<'tcx> {
     kind: GenericKind<'tcx>,
     origin: SubregionOrigin<'tcx>,
-    region: &'tcx Region,
+    region: Region<'tcx>,
     bound: VerifyBound<'tcx>,
 }
 
@@ -86,14 +86,14 @@ pub enum VerifyBound<'tcx> {
     // Put another way, the subject value is known to outlive all
     // regions in {R}, so if any of those outlives 'min, then the
     // bound is met.
-    AnyRegion(Vec<&'tcx Region>),
+    AnyRegion(Vec<Region<'tcx>>),
 
     // B = forall {R} --> all 'r in {R} must outlive 'min
     //
     // Put another way, the subject value is known to outlive some
     // region in {R}, so if all of those outlives 'min, then the bound
     // is met.
-    AllRegions(Vec<&'tcx Region>),
+    AllRegions(Vec<Region<'tcx>>),
 
     // B = exists {B} --> 'min must meet some bound b in {B}
     AnyBound(Vec<VerifyBound<'tcx>>),
@@ -104,8 +104,8 @@ pub enum VerifyBound<'tcx> {
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct TwoRegions<'tcx> {
-    a: &'tcx Region,
-    b: &'tcx Region,
+    a: Region<'tcx>,
+    b: Region<'tcx>,
 }
 
 #[derive(Copy, Clone, PartialEq)]
@@ -128,7 +128,7 @@ pub enum UndoLogEntry<'tcx> {
     AddVerify(usize),
 
     /// We added the given `given`
-    AddGiven(ty::FreeRegion, ty::RegionVid),
+    AddGiven(ty::FreeRegion<'tcx>, ty::RegionVid),
 
     /// We added a GLB/LUB "combinaton variable"
     AddCombination(CombineMapType, TwoRegions<'tcx>),
@@ -153,13 +153,13 @@ pub enum RegionResolutionError<'tcx> {
     /// `ConcreteFailure(o, a, b)`:
     ///
     /// `o` requires that `a <= b`, but this does not hold
-    ConcreteFailure(SubregionOrigin<'tcx>, &'tcx Region, &'tcx Region),
+    ConcreteFailure(SubregionOrigin<'tcx>, Region<'tcx>, Region<'tcx>),
 
     /// `GenericBoundFailure(p, s, a)
     ///
     /// The parameter/associated-type `p` must be known to outlive the lifetime
     /// `a` (but none of the known bounds are sufficient).
-    GenericBoundFailure(SubregionOrigin<'tcx>, GenericKind<'tcx>, &'tcx Region),
+    GenericBoundFailure(SubregionOrigin<'tcx>, GenericKind<'tcx>, Region<'tcx>),
 
     /// `SubSupConflict(v, sub_origin, sub_r, sup_origin, sup_r)`:
     ///
@@ -168,14 +168,14 @@ pub enum RegionResolutionError<'tcx> {
     /// `sub_r <= sup_r` does not hold.
     SubSupConflict(RegionVariableOrigin,
                    SubregionOrigin<'tcx>,
-                   &'tcx Region,
+                   Region<'tcx>,
                    SubregionOrigin<'tcx>,
-                   &'tcx Region),
+                   Region<'tcx>),
 }
 
 #[derive(Clone, Debug)]
 pub enum ProcessedErrorOrigin<'tcx> {
-    ConcreteFailure(SubregionOrigin<'tcx>, &'tcx Region, &'tcx Region),
+    ConcreteFailure(SubregionOrigin<'tcx>, Region<'tcx>, Region<'tcx>),
     VariableFailure(RegionVariableOrigin),
 }
 
@@ -214,7 +214,7 @@ pub struct RegionVarBindings<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     // record the fact that `'a <= 'b` is implied by the fn signature,
     // and then ignore the constraint when solving equations. This is
     // a bit of a hack but seems to work.
-    givens: RefCell<FxHashSet<(ty::FreeRegion, ty::RegionVid)>>,
+    givens: RefCell<FxHashSet<(ty::FreeRegion<'tcx>, ty::RegionVid)>>,
 
     lubs: RefCell<CombineMap<'tcx>>,
     glbs: RefCell<CombineMap<'tcx>>,
@@ -271,12 +271,12 @@ impl TaintDirections {
 
 struct TaintSet<'tcx> {
     directions: TaintDirections,
-    regions: FxHashSet<&'tcx ty::Region>
+    regions: FxHashSet<ty::Region<'tcx>>
 }
 
 impl<'a, 'gcx, 'tcx> TaintSet<'tcx> {
     fn new(directions: TaintDirections,
-           initial_region: &'tcx ty::Region)
+           initial_region: ty::Region<'tcx>)
            -> Self {
         let mut regions = FxHashSet();
         regions.insert(initial_region);
@@ -328,7 +328,7 @@ impl<'a, 'gcx, 'tcx> TaintSet<'tcx> {
         }
     }
 
-    fn into_set(self) -> FxHashSet<&'tcx ty::Region> {
+    fn into_set(self) -> FxHashSet<ty::Region<'tcx>> {
         self.regions
     }
 
@@ -337,8 +337,8 @@ impl<'a, 'gcx, 'tcx> TaintSet<'tcx> {
     }
 
     fn add_edge(&mut self,
-                source: &'tcx ty::Region,
-                target: &'tcx ty::Region) {
+                source: ty::Region<'tcx>,
+                target: ty::Region<'tcx>) {
         if self.directions.incoming {
             if self.regions.contains(&target) {
                 self.regions.insert(source);
@@ -499,7 +499,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// it's just there to make it explicit which snapshot bounds the
     /// skolemized region that results. It should always be the top-most snapshot.
     pub fn push_skolemized(&self, br: ty::BoundRegion, snapshot: &RegionSnapshot)
-                           -> &'tcx Region {
+                           -> Region<'tcx> {
         assert!(self.in_snapshot());
         assert!(self.undo_log.borrow()[snapshot.length] == OpenSnapshot);
 
@@ -513,7 +513,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// completes to remove all trace of the skolemized regions
     /// created in that time.
     pub fn pop_skolemized(&self,
-                          skols: &FxHashSet<&'tcx ty::Region>,
+                          skols: &FxHashSet<ty::Region<'tcx>>,
                           snapshot: &RegionSnapshot) {
         debug!("pop_skolemized_regions(skols={:?})", skols);
 
@@ -567,7 +567,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
         self.skolemization_count.set(snapshot.skolemization_count);
         return;
 
-        fn kill_constraint<'tcx>(skols: &FxHashSet<&'tcx ty::Region>,
+        fn kill_constraint<'tcx>(skols: &FxHashSet<ty::Region<'tcx>>,
                                  undo_entry: &UndoLogEntry<'tcx>)
                                  -> bool {
             match undo_entry {
@@ -596,7 +596,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     }
 
-    pub fn new_bound(&self, debruijn: ty::DebruijnIndex) -> &'tcx Region {
+    pub fn new_bound(&self, debruijn: ty::DebruijnIndex) -> Region<'tcx> {
         // Creates a fresh bound variable for use in GLB computations.
         // See discussion of GLB computation in the large comment at
         // the top of this file for more details.
@@ -662,7 +662,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
         }
     }
 
-    pub fn add_given(&self, sub: ty::FreeRegion, sup: ty::RegionVid) {
+    pub fn add_given(&self, sub: ty::FreeRegion<'tcx>, sup: ty::RegionVid) {
         // cannot add givens once regions are resolved
         assert!(self.values_are_none());
 
@@ -676,8 +676,8 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     pub fn make_eqregion(&self,
                          origin: SubregionOrigin<'tcx>,
-                         sub: &'tcx Region,
-                         sup: &'tcx Region) {
+                         sub: Region<'tcx>,
+                         sup: Region<'tcx>) {
         if sub != sup {
             // Eventually, it would be nice to add direct support for
             // equating regions.
@@ -692,8 +692,8 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     pub fn make_subregion(&self,
                           origin: SubregionOrigin<'tcx>,
-                          sub: &'tcx Region,
-                          sup: &'tcx Region) {
+                          sub: Region<'tcx>,
+                          sup: Region<'tcx>) {
         // cannot add constraints once regions are resolved
         assert!(self.values_are_none());
 
@@ -734,7 +734,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     pub fn verify_generic_bound(&self,
                                 origin: SubregionOrigin<'tcx>,
                                 kind: GenericKind<'tcx>,
-                                sub: &'tcx Region,
+                                sub: Region<'tcx>,
                                 bound: VerifyBound<'tcx>) {
         self.add_verify(Verify {
             kind: kind,
@@ -746,9 +746,9 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     pub fn lub_regions(&self,
                        origin: SubregionOrigin<'tcx>,
-                       a: &'tcx Region,
-                       b: &'tcx Region)
-                       -> &'tcx Region {
+                       a: Region<'tcx>,
+                       b: Region<'tcx>)
+                       -> Region<'tcx> {
         // cannot add constraints once regions are resolved
         assert!(self.values_are_none());
 
@@ -772,9 +772,9 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     pub fn glb_regions(&self,
                        origin: SubregionOrigin<'tcx>,
-                       a: &'tcx Region,
-                       b: &'tcx Region)
-                       -> &'tcx Region {
+                       a: Region<'tcx>,
+                       b: Region<'tcx>)
+                       -> Region<'tcx> {
         // cannot add constraints once regions are resolved
         assert!(self.values_are_none());
 
@@ -796,7 +796,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
         }
     }
 
-    pub fn resolve_var(&self, rid: RegionVid) -> &'tcx ty::Region {
+    pub fn resolve_var(&self, rid: RegionVid) -> ty::Region<'tcx> {
         match *self.values.borrow() {
             None => {
                 span_bug!((*self.var_origins.borrow())[rid.index as usize].span(),
@@ -811,7 +811,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
         }
     }
 
-    pub fn opportunistic_resolve_var(&self, rid: RegionVid) -> &'tcx ty::Region {
+    pub fn opportunistic_resolve_var(&self, rid: RegionVid) -> ty::Region<'tcx> {
         let vid = self.unification_table.borrow_mut().find_value(rid).min_vid;
         self.tcx.mk_region(ty::ReVar(vid))
     }
@@ -825,12 +825,12 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
     pub fn combine_vars<F>(&self,
                            t: CombineMapType,
-                           a: &'tcx Region,
-                           b: &'tcx Region,
+                           a: Region<'tcx>,
+                           b: Region<'tcx>,
                            origin: SubregionOrigin<'tcx>,
                            mut relate: F)
-                           -> &'tcx Region
-        where F: FnMut(&RegionVarBindings<'a, 'gcx, 'tcx>, &'tcx Region, &'tcx Region)
+                           -> Region<'tcx>
+        where F: FnMut(&RegionVarBindings<'a, 'gcx, 'tcx>, Region<'tcx>, Region<'tcx>)
     {
         let vars = TwoRegions { a: a, b: b };
         if let Some(&c) = self.combine_map(t).borrow().get(&vars) {
@@ -869,9 +869,9 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// related to other regions.
     pub fn tainted(&self,
                    mark: &RegionSnapshot,
-                   r0: &'tcx Region,
+                   r0: Region<'tcx>,
                    directions: TaintDirections)
-                   -> FxHashSet<&'tcx ty::Region> {
+                   -> FxHashSet<ty::Region<'tcx>> {
         debug!("tainted(mark={:?}, r0={:?}, directions={:?})",
                mark, r0, directions);
 
@@ -892,7 +892,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// constraints, assuming such values can be found; if they cannot,
     /// errors are reported.
     pub fn resolve_regions(&self,
-                           free_regions: &FreeRegionMap,
+                           free_regions: &FreeRegionMap<'tcx>,
                            subject_node: ast::NodeId)
                            -> Vec<RegionResolutionError<'tcx>> {
         debug!("RegionVarBindings: resolve_regions()");
@@ -903,10 +903,10 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     }
 
     fn lub_concrete_regions(&self,
-                            free_regions: &FreeRegionMap,
-                            a: &'tcx Region,
-                            b: &'tcx Region)
-                            -> &'tcx Region {
+                            free_regions: &FreeRegionMap<'tcx>,
+                            a: Region<'tcx>,
+                            b: Region<'tcx>)
+                            -> Region<'tcx> {
         match (a, b) {
             (&ReLateBound(..), _) |
             (_, &ReLateBound(..)) |
@@ -961,8 +961,8 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
                     self.tcx.region_maps().nearest_common_ancestor(a_id, b_id)))
             }
 
-            (&ReFree(a_fr), &ReFree(b_fr)) => {
-                self.tcx.mk_region(free_regions.lub_free_regions(a_fr, b_fr))
+            (&ReFree(_), &ReFree(_)) => {
+                free_regions.lub_free_regions(self.tcx, a, b)
             }
 
             // For these types, we cannot define any additional
@@ -983,12 +983,12 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
 #[derive(Copy, Clone, Debug)]
 pub enum VarValue<'tcx> {
-    Value(&'tcx Region),
+    Value(Region<'tcx>),
     ErrorValue,
 }
 
 struct RegionAndOrigin<'tcx> {
-    region: &'tcx Region,
+    region: Region<'tcx>,
     origin: SubregionOrigin<'tcx>,
 }
 
@@ -996,7 +996,7 @@ type RegionGraph<'tcx> = graph::Graph<(), Constraint<'tcx>>;
 
 impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     fn infer_variable_values(&self,
-                             free_regions: &FreeRegionMap,
+                             free_regions: &FreeRegionMap<'tcx>,
                              errors: &mut Vec<RegionResolutionError<'tcx>>,
                              subject: ast::NodeId)
                              -> Vec<VarValue<'tcx>> {
@@ -1056,7 +1056,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
         }
     }
 
-    fn expansion(&self, free_regions: &FreeRegionMap, var_values: &mut [VarValue<'tcx>]) {
+    fn expansion(&self, free_regions: &FreeRegionMap<'tcx>, var_values: &mut [VarValue<'tcx>]) {
         self.iterate_until_fixed_point("Expansion", |constraint, origin| {
             debug!("expansion: constraint={:?} origin={:?}",
                    constraint, origin);
@@ -1085,8 +1085,8 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     }
 
     fn expand_node(&self,
-                   free_regions: &FreeRegionMap,
-                   a_region: &'tcx Region,
+                   free_regions: &FreeRegionMap<'tcx>,
+                   a_region: Region<'tcx>,
                    b_vid: RegionVid,
                    b_data: &mut VarValue<'tcx>)
                    -> bool {
@@ -1132,7 +1132,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// cases where the region cannot grow larger than a fixed point)
     /// and check that they are satisfied.
     fn collect_errors(&self,
-                      free_regions: &FreeRegionMap,
+                      free_regions: &FreeRegionMap<'tcx>,
                       var_data: &mut Vec<VarValue<'tcx>>,
                       errors: &mut Vec<RegionResolutionError<'tcx>>) {
         let constraints = self.constraints.borrow();
@@ -1209,7 +1209,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     /// Go over the variables that were declared to be error variables
     /// and create a `RegionResolutionError` for each of them.
     fn collect_var_errors(&self,
-                          free_regions: &FreeRegionMap,
+                          free_regions: &FreeRegionMap<'tcx>,
                           var_data: &[VarValue<'tcx>],
                           graph: &RegionGraph<'tcx>,
                           errors: &mut Vec<RegionResolutionError<'tcx>>) {
@@ -1311,7 +1311,7 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
     }
 
     fn collect_error_for_expanding_node(&self,
-                                        free_regions: &FreeRegionMap,
+                                        free_regions: &FreeRegionMap<'tcx>,
                                         graph: &RegionGraph<'tcx>,
                                         dup_vec: &mut [u32],
                                         node_idx: RegionVid,
@@ -1480,8 +1480,8 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
 
 fn normalize<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                              values: &Vec<VarValue<'tcx>>,
-                             r: &'tcx ty::Region)
-                             -> &'tcx ty::Region {
+                             r: ty::Region<'tcx>)
+                             -> ty::Region<'tcx> {
     match *r {
         ty::ReVar(rid) => lookup(tcx, values, rid),
         _ => r,
@@ -1491,7 +1491,7 @@ fn normalize<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
 fn lookup<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                           values: &Vec<VarValue<'tcx>>,
                           rid: ty::RegionVid)
-                          -> &'tcx ty::Region {
+                          -> ty::Region<'tcx> {
     match values[rid.index as usize] {
         Value(r) => r,
         ErrorValue => tcx.types.re_static, // Previously reported error.
@@ -1539,7 +1539,7 @@ impl<'a, 'gcx, 'tcx> GenericKind<'tcx> {
 }
 
 impl<'a, 'gcx, 'tcx> VerifyBound<'tcx> {
-    fn for_each_region(&self, f: &mut FnMut(&'tcx ty::Region)) {
+    fn for_each_region(&self, f: &mut FnMut(ty::Region<'tcx>)) {
         match self {
             &VerifyBound::AnyRegion(ref rs) |
             &VerifyBound::AllRegions(ref rs) => for &r in rs {
@@ -1592,9 +1592,9 @@ impl<'a, 'gcx, 'tcx> VerifyBound<'tcx> {
     }
 
     fn is_met(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
-              free_regions: &FreeRegionMap,
+              free_regions: &FreeRegionMap<'tcx>,
               var_values: &Vec<VarValue<'tcx>>,
-              min: &'tcx ty::Region)
+              min: ty::Region<'tcx>)
               -> bool {
         match self {
             &VerifyBound::AnyRegion(ref rs) =>

src/librustc/infer/resolve.rs

@@ -72,7 +72,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for OpportunisticTypeAndRegionResolv
         }
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReVar(rid) => self.infcx.region_vars.opportunistic_resolve_var(rid),
             _ => r,
@@ -138,7 +138,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for FullTypeResolver<'a, 'gcx, 'tcx>
         }
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReVar(rid) => self.infcx.region_vars.resolve_var(rid),
             _ => r,

src/librustc/infer/sub.rs

@@ -127,8 +127,8 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
         }
     }
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region> {
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?}) self.cause={:?}",
                self.tag(), a, b, self.fields.cause);
 

src/librustc/middle/expr_use_visitor.rs

@@ -75,7 +75,7 @@ pub trait Delegate<'tcx> {
               borrow_id: ast::NodeId,
               borrow_span: Span,
               cmt: mc::cmt<'tcx>,
-              loan_region: &'tcx ty::Region,
+              loan_region: ty::Region<'tcx>,
               bk: ty::BorrowKind,
               loan_cause: LoanCause);
 
@@ -347,7 +347,7 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
 
     fn borrow_expr(&mut self,
                    expr: &hir::Expr,
-                   r: &'tcx ty::Region,
+                   r: ty::Region<'tcx>,
                    bk: ty::BorrowKind,
                    cause: LoanCause) {
         debug!("borrow_expr(expr={:?}, r={:?}, bk={:?})",

src/librustc/middle/free_region.rs

@@ -15,18 +15,21 @@
 //! `TransitiveRelation` type and use that to decide when one free
 //! region outlives another and so forth.
 
-use ty::{self, TyCtxt, FreeRegion, Region};
+use ty::{self, Lift, TyCtxt, Region};
 use ty::wf::ImpliedBound;
 use rustc_data_structures::transitive_relation::TransitiveRelation;
 
 #[derive(Clone, RustcEncodable, RustcDecodable)]
-pub struct FreeRegionMap {
+pub struct FreeRegionMap<'tcx> {
     // Stores the relation `a < b`, where `a` and `b` are regions.
-    relation: TransitiveRelation<Region>
+    //
+    // Invariant: only free regions like `'x` or `'static` are stored
+    // in this relation, not scopes.
+    relation: TransitiveRelation<Region<'tcx>>
 }
 
-impl FreeRegionMap {
-    pub fn new() -> FreeRegionMap {
+impl<'tcx> FreeRegionMap<'tcx> {
+    pub fn new() -> Self {
         FreeRegionMap { relation: TransitiveRelation::new() }
     }
 
@@ -34,15 +37,16 @@ impl FreeRegionMap {
         self.relation.is_empty()
     }
 
-    pub fn relate_free_regions_from_implied_bounds<'tcx>(&mut self,
+    pub fn relate_free_regions_from_implied_bounds(&mut self,
                                                    implied_bounds: &[ImpliedBound<'tcx>])
     {
         debug!("relate_free_regions_from_implied_bounds()");
         for implied_bound in implied_bounds {
             debug!("implied bound: {:?}", implied_bound);
             match *implied_bound {
-                ImpliedBound::RegionSubRegion(&ty::ReFree(free_a), &ty::ReFree(free_b)) => {
-                    self.relate_free_regions(free_a, free_b);
+                ImpliedBound::RegionSubRegion(a @ &ty::ReFree(_), b @ &ty::ReFree(_)) |
+                ImpliedBound::RegionSubRegion(a @ &ty::ReStatic, b @ &ty::ReFree(_)) => {
+                    self.relate_regions(a, b);
                 }
                 ImpliedBound::RegionSubRegion(..) |
                 ImpliedBound::RegionSubParam(..) |
@@ -53,7 +57,7 @@ impl FreeRegionMap {
     }
 
     pub fn relate_free_regions_from_predicates(&mut self,
-                                               predicates: &[ty::Predicate]) {
+                                               predicates: &[ty::Predicate<'tcx>]) {
         debug!("relate_free_regions_from_predicates(predicates={:?})", predicates);
         for predicate in predicates {
             match *predicate {
@@ -69,12 +73,15 @@ impl FreeRegionMap {
                 }
                 ty::Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
                     match (r_a, r_b) {
+                        // `'static: 'x` is not notable
                         (&ty::ReStatic, &ty::ReFree(_)) => {},
-                        (&ty::ReFree(fr_a), &ty::ReStatic) => self.relate_to_static(fr_a),
-                        (&ty::ReFree(fr_a), &ty::ReFree(fr_b)) => {
+
+                        (&ty::ReFree(_), &ty::ReStatic) |
+                        (&ty::ReFree(_), &ty::ReFree(_)) => {
                             // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
-                            self.relate_free_regions(fr_b, fr_a);
+                            self.relate_regions(r_b, r_a);
                         }
+
                         _ => {
                             // All named regions are instantiated with free regions.
                             bug!("record_region_bounds: non free region: {:?} / {:?}",
@@ -87,47 +94,35 @@ impl FreeRegionMap {
         }
     }
 
-    fn relate_to_static(&mut self, sup: FreeRegion) {
-        self.relation.add(ty::ReStatic, ty::ReFree(sup));
+    fn relate_regions(&mut self, sub: Region<'tcx>, sup: Region<'tcx>) {
+        assert!(match *sub { ty::ReFree(_) | ty::ReStatic => true, _ => false });
+        assert!(match *sup { ty::ReFree(_) | ty::ReStatic => true, _ => false });
+        self.relation.add(sub, sup)
     }
 
-    fn relate_free_regions(&mut self, sub: FreeRegion, sup: FreeRegion) {
-        self.relation.add(ty::ReFree(sub), ty::ReFree(sup))
-    }
-
-    /// Determines whether two free regions have a subregion relationship
-    /// by walking the graph encoded in `map`.  Note that
-    /// it is possible that `sub != sup` and `sub <= sup` and `sup <= sub`
-    /// (that is, the user can give two different names to the same lifetime).
-    pub fn sub_free_region(&self, sub: FreeRegion, sup: FreeRegion) -> bool {
-        let result = sub == sup || {
-            let sub = ty::ReFree(sub);
-            let sup = ty::ReFree(sup);
-            self.relation.contains(&sub, &sup) || self.relation.contains(&ty::ReStatic, &sup)
-        };
-        debug!("sub_free_region(sub={:?}, sup={:?}) = {:?}", sub, sup, result);
-        result
-    }
-
-    pub fn lub_free_regions(&self, fr_a: FreeRegion, fr_b: FreeRegion) -> Region {
-        let r_a = ty::ReFree(fr_a);
-        let r_b = ty::ReFree(fr_b);
-        let result = if fr_a == fr_b { r_a } else {
+    pub fn lub_free_regions<'a, 'gcx>(&self,
+                                      tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                      r_a: Region<'tcx>,
+                                      r_b: Region<'tcx>)
+                                      -> Region<'tcx> {
+        assert!(match *r_a { ty::ReFree(_) => true, _ => false });
+        assert!(match *r_b { ty::ReFree(_) => true, _ => false });
+        let result = if r_a == r_b { r_a } else {
             match self.relation.postdom_upper_bound(&r_a, &r_b) {
-                None => ty::ReStatic,
+                None => tcx.mk_region(ty::ReStatic),
                 Some(r) => *r,
             }
         };
-        debug!("lub_free_regions(fr_a={:?}, fr_b={:?}) = {:?}", fr_a, fr_b, result);
+        debug!("lub_free_regions(r_a={:?}, r_b={:?}) = {:?}", r_a, r_b, result);
         result
     }
 
     /// Determines whether one region is a subregion of another.  This is intended to run *after
     /// inference* and sadly the logic is somewhat duplicated with the code in infer.rs.
-    pub fn is_subregion_of(&self,
-                           tcx: TyCtxt,
-                           sub_region: &ty::Region,
-                           super_region: &ty::Region)
+    pub fn is_subregion_of<'a, 'gcx>(&self,
+                                     tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                     sub_region: ty::Region<'tcx>,
+                                     super_region: ty::Region<'tcx>)
                                      -> bool {
         let result = sub_region == super_region || {
             match (sub_region, super_region) {
@@ -141,17 +136,18 @@ impl FreeRegionMap {
                 (&ty::ReScope(sub_scope), &ty::ReFree(fr)) => {
                     // 1. It is safe to unwrap `fr.scope` because we
                     // should only ever wind up comparing against
-                    // `ReScope` in the context of a method or fn
+                    // `ReScope` in the context of a method or
                     // body, where `fr.scope` should be `Some`.
                     tcx.region_maps().is_subscope_of(sub_scope, fr.scope.unwrap() /*1*/) ||
-                        self.is_static(fr)
+                        self.is_static(tcx, super_region)
                 }
 
-                (&ty::ReFree(sub_fr), &ty::ReFree(super_fr)) =>
-                    self.sub_free_region(sub_fr, super_fr),
+                (&ty::ReFree(_), &ty::ReFree(_)) =>
+                    self.relation.contains(&sub_region, &super_region) ||
+                        self.is_static(tcx, super_region),
 
-                (&ty::ReStatic, &ty::ReFree(sup_fr)) =>
-                    self.is_static(sup_fr),
+                (&ty::ReStatic, &ty::ReFree(_)) =>
+                    self.is_static(tcx, super_region),
 
                 _ =>
                     false,
@@ -163,28 +159,28 @@ impl FreeRegionMap {
     }
 
     /// Determines whether this free-region is required to be 'static
-    pub fn is_static(&self, super_region: ty::FreeRegion) -> bool {
+    fn is_static<'a, 'gcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, super_region: ty::Region<'tcx>)
+                           -> bool {
         debug!("is_static(super_region={:?})", super_region);
-        self.relation.contains(&ty::ReStatic, &ty::ReFree(super_region))
+        match *super_region {
+            ty::ReStatic => true,
+            ty::ReFree(_) => {
+                let re_static = tcx.mk_region(ty::ReStatic);
+                self.relation.contains(&re_static, &super_region)
+            }
+            _ => bug!("only free regions should be given to `is_static`")
+        }
     }
 }
 
-#[cfg(test)]
-fn free_region(index: u32) -> FreeRegion {
-    FreeRegion { scope: None, bound_region: ty::BoundRegion::BrAnon(index) }
-}
-
-#[test]
-fn lub() {
-    // a very VERY basic test, but see the tests in
-    // TransitiveRelation, which are much more thorough.
-    let frs: Vec<_> = (0..3).map(|i| free_region(i)).collect();
-    let mut map = FreeRegionMap::new();
-    map.relate_free_regions(frs[0], frs[2]);
-    map.relate_free_regions(frs[1], frs[2]);
-    assert_eq!(map.lub_free_regions(frs[0], frs[1]), ty::ReFree(frs[2]));
-}
-
-impl_stable_hash_for!(struct FreeRegionMap {
+impl_stable_hash_for!(struct FreeRegionMap<'tcx> {
     relation
 });
+
+impl<'a, 'tcx> Lift<'tcx> for FreeRegionMap<'a> {
+    type Lifted = FreeRegionMap<'tcx>;
+    fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<FreeRegionMap<'tcx>> {
+        self.relation.maybe_map(|&fr| fr.lift_to_tcx(tcx))
+                     .map(|relation| FreeRegionMap { relation })
+    }
+}

src/librustc/middle/liveness.rs

@@ -1441,7 +1441,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
         // and must outlive the *call-site* of the function.
         let fn_ret =
             self.ir.tcx.liberate_late_bound_regions(
-                Some(self.ir.tcx.region_maps().call_site_extent(id, body.value.id)),
+                Some(self.ir.tcx.call_site_extent(id, body.value.id)),
                 &fn_ret);
 
         if !fn_ret.is_never() && self.live_on_entry(entry_ln, self.s.no_ret_var).is_some() {

src/librustc/middle/mem_categorization.rs

@@ -89,7 +89,7 @@ use std::rc::Rc;
 #[derive(Clone, PartialEq)]
 pub enum Categorization<'tcx> {
     // temporary val, argument is its scope
-    Rvalue(&'tcx ty::Region, &'tcx ty::Region),
+    Rvalue(ty::Region<'tcx>, ty::Region<'tcx>),
     StaticItem,
     Upvar(Upvar),                          // upvar referenced by closure env
     Local(ast::NodeId),                    // local variable
@@ -114,13 +114,13 @@ pub enum PointerKind<'tcx> {
     Unique,
 
     /// `&T`
-    BorrowedPtr(ty::BorrowKind, &'tcx ty::Region),
+    BorrowedPtr(ty::BorrowKind, ty::Region<'tcx>),
 
     /// `*T`
     UnsafePtr(hir::Mutability),
 
     /// Implicit deref of the `&T` that results from an overloaded index `[]`.
-    Implicit(ty::BorrowKind, &'tcx ty::Region),
+    Implicit(ty::BorrowKind, ty::Region<'tcx>),
 }
 
 // We use the term "interior" to mean "something reachable from the
@@ -796,7 +796,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
             // The environment of a closure is guaranteed to
             // outlive any bindings introduced in the body of the
             // closure itself.
-            scope: Some(self.tcx().region_maps().item_extent(fn_body_id)),
+            scope: Some(self.tcx().item_extent(fn_body_id)),
             bound_region: ty::BrEnv
         }));
 
@@ -842,10 +842,10 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
 
     /// Returns the lifetime of a temporary created by expr with id `id`.
     /// This could be `'static` if `id` is part of a constant expression.
-    pub fn temporary_scope(&self, id: ast::NodeId) -> (&'tcx ty::Region, &'tcx ty::Region)
+    pub fn temporary_scope(&self, id: ast::NodeId) -> (ty::Region<'tcx>, ty::Region<'tcx>)
     {
         let (scope, old_scope) =
-            self.tcx().region_maps().old_and_new_temporary_scope(id);
+            self.tcx().region_maps().old_and_new_temporary_scope(self.tcx(), id);
         (self.tcx().mk_region(match scope {
             Some(scope) => ty::ReScope(scope),
             None => ty::ReStatic
@@ -887,8 +887,8 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
     pub fn cat_rvalue(&self,
                       cmt_id: ast::NodeId,
                       span: Span,
-                      temp_scope: &'tcx ty::Region,
-                      old_temp_scope: &'tcx ty::Region,
+                      temp_scope: ty::Region<'tcx>,
+                      old_temp_scope: ty::Region<'tcx>,
                       expr_ty: Ty<'tcx>) -> cmt<'tcx> {
         let ret = Rc::new(cmt_ {
             id:cmt_id,

src/librustc/middle/region.rs

@@ -17,14 +17,12 @@
 //! `middle/infer/region_inference/README.md`
 
 use hir::map as hir_map;
-use session::Session;
 use util::nodemap::{FxHashMap, NodeMap, NodeSet};
 use ty;
 
-use std::collections::hash_map::Entry;
-use std::fmt;
 use std::mem;
 use std::rc::Rc;
+use serialize;
 use syntax::codemap;
 use syntax::ast::{self, NodeId};
 use syntax_pos::Span;
@@ -34,33 +32,12 @@ use ty::maps::Providers;
 use hir;
 use hir::def_id::{CrateNum, LOCAL_CRATE};
 use hir::intravisit::{self, Visitor, FnKind, NestedVisitorMap};
-use hir::{Body, Block, Item, FnDecl, Arm, Pat, PatKind, Stmt, Expr, Local};
+use hir::{Block, Item, FnDecl, Arm, Pat, PatKind, Stmt, Expr, Local};
 
-#[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, RustcEncodable,
-           RustcDecodable, Copy)]
-pub struct CodeExtent(u32);
+pub type CodeExtent<'tcx> = &'tcx CodeExtentData;
 
-impl fmt::Debug for CodeExtent {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "CodeExtent({:?}", self.0)?;
-
-        ty::tls::with_opt(|opt_tcx| {
-            if let Some(tcx) = opt_tcx {
-                let region_maps = tcx.region_maps();
-                {
-                    let code_extents = &region_maps.code_extents;
-                    if let Some(data) = code_extents.get(self.0 as usize) {
-                        write!(f, "/{:?}", data)?;
-                    }
-                    mem::drop(code_extents); // FIXME why is this necessary?
-                }
-            }
-            Ok(())
-        })?;
-
-        write!(f, ")")
-    }
-}
+impl<'tcx> serialize::UseSpecializedEncodable for CodeExtent<'tcx> {}
+impl<'tcx> serialize::UseSpecializedDecodable for CodeExtent<'tcx> {}
 
 /// CodeExtent represents a statically-describable extent that can be
 /// used to bound the lifetime/region for values.
@@ -123,7 +100,7 @@ impl fmt::Debug for CodeExtent {
 /// placate the same deriving in `ty::FreeRegion`, but we may want to
 /// actually attach a more meaningful ordering to scopes than the one
 /// generated via deriving here.
-#[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Debug, Copy)]
+#[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Debug, Copy, RustcEncodable, RustcDecodable)]
 pub enum CodeExtentData {
     Misc(ast::NodeId),
 
@@ -150,8 +127,8 @@ pub struct CallSiteScopeData {
 }
 
 impl CallSiteScopeData {
-    pub fn to_code_extent(&self, region_maps: &RegionMaps) -> CodeExtent {
-        region_maps.lookup_code_extent(
+    pub fn to_code_extent<'a, 'tcx, 'gcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> CodeExtent<'tcx> {
+        tcx.intern_code_extent(
             match *self {
                 CallSiteScopeData { fn_id, body_id } =>
                     CodeExtentData::CallSiteScope { fn_id: fn_id, body_id: body_id },
@@ -200,20 +177,14 @@ impl CodeExtentData {
             CodeExtentData::ParameterScope { fn_id: _, body_id } => body_id,
         }
     }
-}
-
-impl CodeExtent {
-    pub fn node_id(&self, region_maps: &RegionMaps) -> ast::NodeId {
-        region_maps.code_extent_data(*self).node_id()
-    }
 
     /// Returns the span of this CodeExtent.  Note that in general the
     /// returned span may not correspond to the span of any node id in
     /// the AST.
-    pub fn span(&self, region_maps: &RegionMaps, hir_map: &hir_map::Map) -> Option<Span> {
-        match hir_map.find(self.node_id(region_maps)) {
+    pub fn span(&self, hir_map: &hir_map::Map) -> Option<Span> {
+        match hir_map.find(self.node_id()) {
             Some(hir_map::NodeBlock(ref blk)) => {
-                match region_maps.code_extent_data(*self) {
+                match *self {
                     CodeExtentData::CallSiteScope { .. } |
                     CodeExtentData::ParameterScope { .. } |
                     CodeExtentData::Misc(_) |
@@ -242,20 +213,18 @@ impl CodeExtent {
 }
 
 /// The region maps encode information about region relationships.
-pub struct RegionMaps {
-    code_extents: Vec<CodeExtentData>,
-    code_extent_interner: FxHashMap<CodeExtentData, CodeExtent>,
+pub struct RegionMaps<'tcx> {
     /// `scope_map` maps from a scope id to the enclosing scope id;
     /// this is usually corresponding to the lexical nesting, though
     /// in the case of closures the parent scope is the innermost
     /// conditional expression or repeating block. (Note that the
     /// enclosing scope id for the block associated with a closure is
     /// the closure itself.)
-    scope_map: Vec<Option<CodeExtent>>,
+    scope_map: FxHashMap<CodeExtent<'tcx>, CodeExtent<'tcx>>,
 
     /// `var_map` maps from a variable or binding id to the block in
     /// which that variable is declared.
-    var_map: NodeMap<CodeExtent>,
+    var_map: NodeMap<CodeExtent<'tcx>>,
 
     /// `rvalue_scopes` includes entries for those expressions whose cleanup scope is
     /// larger than the default. The map goes from the expression id
@@ -263,14 +232,14 @@ pub struct RegionMaps {
     /// table, the appropriate cleanup scope is the innermost
     /// enclosing statement, conditional expression, or repeating
     /// block (see `terminating_scopes`).
-    rvalue_scopes: NodeMap<CodeExtent>,
+    rvalue_scopes: NodeMap<CodeExtent<'tcx>>,
 
     /// Records the value of rvalue scopes before they were shrunk by
     /// #36082, for error reporting.
     ///
     /// FIXME: this should be temporary. Remove this by 1.18.0 or
     /// so.
-    shrunk_rvalue_scopes: NodeMap<CodeExtent>,
+    shrunk_rvalue_scopes: NodeMap<CodeExtent<'tcx>>,
 
     /// Encodes the hierarchy of fn bodies. Every fn body (including
     /// closures) forms its own distinct region hierarchy, rooted in
@@ -286,7 +255,7 @@ pub struct RegionMaps {
 }
 
 #[derive(Debug, Copy, Clone)]
-pub struct Context {
+pub struct Context<'tcx> {
     /// the root of the current region tree. This is typically the id
     /// of the innermost fn body. Each fn forms its own disjoint tree
     /// in the region hierarchy. These fn bodies are themselves
@@ -296,21 +265,21 @@ pub struct Context {
     root_id: Option<ast::NodeId>,
 
     /// the scope that contains any new variables declared
-    var_parent: Option<CodeExtent>,
+    var_parent: Option<CodeExtent<'tcx>>,
 
     /// region parent of expressions etc
-    parent: Option<CodeExtent>,
+    parent: Option<CodeExtent<'tcx>>,
 }
 
-struct RegionResolutionVisitor<'hir: 'a, 'a> {
-    sess: &'a Session,
+struct RegionResolutionVisitor<'a, 'tcx: 'a> {
+    tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
     // Generated maps:
-    region_maps: &'a mut RegionMaps,
+    region_maps: &'a mut RegionMaps<'tcx>,
 
-    cx: Context,
+    cx: Context<'tcx>,
 
-    map: &'a hir_map::Map<'hir>,
+    map: &'a hir_map::Map<'tcx>,
 
     /// `terminating_scopes` is a set containing the ids of each
     /// statement, or conditional/repeating expression. These scopes
@@ -336,64 +305,13 @@ struct RegionResolutionVisitor<'hir: 'a, 'a> {
 }
 
 
-impl RegionMaps {
-    pub fn lookup_code_extent(&self, e: CodeExtentData) -> CodeExtent {
-        match self.code_extent_interner.get(&e) {
-            Some(&d) => d,
-            None => bug!("unknown code extent {:?}", e)
+impl<'tcx> RegionMaps<'tcx> {
+    pub fn each_encl_scope<E>(&self, mut e:E) where E: FnMut(CodeExtent<'tcx>, CodeExtent<'tcx>) {
+        for (&child, &parent) in &self.scope_map {
+            e(child, parent)
         }
     }
-    pub fn node_extent(&self, n: ast::NodeId) -> CodeExtent {
-        self.lookup_code_extent(CodeExtentData::Misc(n))
-    }
-    // Returns the code extent for an item - the destruction scope.
-    pub fn item_extent(&self, n: ast::NodeId) -> CodeExtent {
-        self.lookup_code_extent(CodeExtentData::DestructionScope(n))
-    }
-    pub fn call_site_extent(&self, fn_id: ast::NodeId, body_id: ast::NodeId) -> CodeExtent {
-        assert!(fn_id != body_id);
-        self.lookup_code_extent(CodeExtentData::CallSiteScope { fn_id: fn_id, body_id: body_id })
-    }
-    pub fn opt_destruction_extent(&self, n: ast::NodeId) -> Option<CodeExtent> {
-        self.code_extent_interner.get(&CodeExtentData::DestructionScope(n)).cloned()
-    }
-    pub fn intern_code_extent(&mut self,
-                              e: CodeExtentData,
-                              parent: Option<CodeExtent>) -> CodeExtent {
-        match self.code_extent_interner.entry(e) {
-            Entry::Occupied(_) => {
-                bug!("intern_code_extent: already exists")
-            }
-            Entry::Vacant(v) => {
-                if self.code_extents.len() > 0xffffffffusize {
-                    bug!() // should pass a sess,
-                           // but this isn't the only place
-                }
-                let idx = CodeExtent(self.code_extents.len() as u32);
-                debug!("CodeExtent({:?}) = {:?} [parent={:?}]", idx, e, parent);
-                self.code_extents.push(e);
-                self.scope_map.push(parent);
-                *v.insert(idx)
-            }
-        }
-    }
-    pub fn intern_node(&mut self,
-                       n: ast::NodeId,
-                       parent: Option<CodeExtent>) -> CodeExtent {
-        self.intern_code_extent(CodeExtentData::Misc(n), parent)
-    }
-    pub fn code_extent_data(&self, e: CodeExtent) -> CodeExtentData {
-        self.code_extents[e.0 as usize]
-    }
-    pub fn each_encl_scope<E>(&self, mut e:E) where E: FnMut(&CodeExtent, &CodeExtent) {
-        for child_id in 1..self.code_extents.len() {
-            let child = CodeExtent(child_id as u32);
-            if let Some(parent) = self.opt_encl_scope(child) {
-                e(&child, &parent)
-            }
-        }
-    }
-    pub fn each_var_scope<E>(&self, mut e:E) where E: FnMut(&ast::NodeId, &CodeExtent) {
+    pub fn each_var_scope<E>(&self, mut e:E) where E: FnMut(&ast::NodeId, CodeExtent<'tcx>) {
         for (child, parent) in self.var_map.iter() {
             e(child, parent)
         }
@@ -419,45 +337,48 @@ impl RegionMaps {
         }
     }
 
-    fn record_var_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent) {
+    fn record_var_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent<'tcx>) {
         debug!("record_var_scope(sub={:?}, sup={:?})", var, lifetime);
-        assert!(var != lifetime.node_id(self));
+        assert!(var != lifetime.node_id());
         self.var_map.insert(var, lifetime);
     }
 
-    fn record_rvalue_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent) {
+    fn record_rvalue_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent<'tcx>) {
         debug!("record_rvalue_scope(sub={:?}, sup={:?})", var, lifetime);
-        assert!(var != lifetime.node_id(self));
+        assert!(var != lifetime.node_id());
         self.rvalue_scopes.insert(var, lifetime);
     }
 
-    fn record_shrunk_rvalue_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent) {
+    fn record_shrunk_rvalue_scope(&mut self, var: ast::NodeId, lifetime: CodeExtent<'tcx>) {
         debug!("record_rvalue_scope(sub={:?}, sup={:?})", var, lifetime);
-        assert!(var != lifetime.node_id(self));
+        assert!(var != lifetime.node_id());
         self.shrunk_rvalue_scopes.insert(var, lifetime);
     }
 
-    pub fn opt_encl_scope(&self, id: CodeExtent) -> Option<CodeExtent> {
+    pub fn opt_encl_scope(&self, id: CodeExtent<'tcx>) -> Option<CodeExtent<'tcx>> {
         //! Returns the narrowest scope that encloses `id`, if any.
-        self.scope_map[id.0 as usize]
+        self.scope_map.get(&id).cloned()
     }
 
     #[allow(dead_code)] // used in cfg
-    pub fn encl_scope(&self, id: CodeExtent) -> CodeExtent {
+    pub fn encl_scope(&self, id: CodeExtent<'tcx>) -> CodeExtent<'tcx> {
         //! Returns the narrowest scope that encloses `id`, if any.
         self.opt_encl_scope(id).unwrap()
     }
 
     /// Returns the lifetime of the local variable `var_id`
-    pub fn var_scope(&self, var_id: ast::NodeId) -> CodeExtent {
+    pub fn var_scope(&self, var_id: ast::NodeId) -> CodeExtent<'tcx> {
         match self.var_map.get(&var_id) {
             Some(&r) => r,
             None => { bug!("no enclosing scope for id {:?}", var_id); }
         }
     }
 
-    pub fn temporary_scope2(&self, expr_id: ast::NodeId) -> (Option<CodeExtent>, bool) {
-        let temporary_scope = self.temporary_scope(expr_id);
+    pub fn temporary_scope2<'a, 'gcx: 'tcx>(&self,
+                                            tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                            expr_id: ast::NodeId)
+                                            -> (Option<CodeExtent<'tcx>>, bool) {
+        let temporary_scope = self.temporary_scope(tcx, expr_id);
         let was_shrunk = match self.shrunk_rvalue_scopes.get(&expr_id) {
             Some(&s) => {
                 info!("temporary_scope2({:?}, scope={:?}, shrunk={:?})",
@@ -470,17 +391,23 @@ impl RegionMaps {
         (temporary_scope, was_shrunk)
     }
 
-    pub fn old_and_new_temporary_scope(&self, expr_id: ast::NodeId) ->
-        (Option<CodeExtent>, Option<CodeExtent>)
+    pub fn old_and_new_temporary_scope<'a, 'gcx: 'tcx>(&self,
+                                                       tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                                       expr_id: ast::NodeId)
+                                                       -> (Option<CodeExtent<'tcx>>,
+                                                           Option<CodeExtent<'tcx>>)
     {
-        let temporary_scope = self.temporary_scope(expr_id);
+        let temporary_scope = self.temporary_scope(tcx, expr_id);
         (temporary_scope,
          self.shrunk_rvalue_scopes
              .get(&expr_id).cloned()
              .or(temporary_scope))
     }
 
-    pub fn temporary_scope(&self, expr_id: ast::NodeId) -> Option<CodeExtent> {
+    pub fn temporary_scope<'a, 'gcx: 'tcx>(&self,
+                                           tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                           expr_id: ast::NodeId)
+                                           -> Option<CodeExtent<'tcx>> {
         //! Returns the scope when temp created by expr_id will be cleaned up
 
         // check for a designated rvalue scope
@@ -489,17 +416,14 @@ impl RegionMaps {
             return Some(s);
         }
 
-        let scope_map : &[Option<CodeExtent>] = &self.scope_map;
-        let code_extents: &[CodeExtentData] = &self.code_extents;
-
         // else, locate the innermost terminating scope
         // if there's one. Static items, for instance, won't
         // have an enclosing scope, hence no scope will be
         // returned.
-        let mut id = self.node_extent(expr_id);
+        let mut id = tcx.node_extent(expr_id);
 
-        while let Some(p) = scope_map[id.0 as usize] {
-            match code_extents[p.0 as usize] {
+        while let Some(&p) = self.scope_map.get(id) {
+            match *p {
                 CodeExtentData::DestructionScope(..) => {
                     debug!("temporary_scope({:?}) = {:?} [enclosing]",
                            expr_id, id);
@@ -513,7 +437,7 @@ impl RegionMaps {
         return None;
     }
 
-    pub fn var_region(&self, id: ast::NodeId) -> ty::Region {
+    pub fn var_region(&self, id: ast::NodeId) -> ty::RegionKind<'tcx> {
         //! Returns the lifetime of the variable `id`.
 
         let scope = ty::ReScope(self.var_scope(id));
@@ -555,9 +479,9 @@ impl RegionMaps {
     /// Finds the nearest common ancestor (if any) of two scopes.  That is, finds the smallest
     /// scope which is greater than or equal to both `scope_a` and `scope_b`.
     pub fn nearest_common_ancestor(&self,
-                                   scope_a: CodeExtent,
-                                   scope_b: CodeExtent)
-                                   -> CodeExtent {
+                                   scope_a: CodeExtent<'tcx>,
+                                   scope_b: CodeExtent<'tcx>)
+                                   -> CodeExtent<'tcx> {
         if scope_a == scope_b { return scope_a; }
 
         /// [1] The initial values for `a_buf` and `b_buf` are not used.
@@ -565,10 +489,10 @@ impl RegionMaps {
         /// is re-initialized with new values (or else fallback to a
         /// heap-allocated vector).
         let mut a_buf: [CodeExtent; 32] = [scope_a /* [1] */; 32];
-        let mut a_vec: Vec<CodeExtent> = vec![];
+        let mut a_vec: Vec<CodeExtent<'tcx>> = vec![];
         let mut b_buf: [CodeExtent; 32] = [scope_b /* [1] */; 32];
-        let mut b_vec: Vec<CodeExtent> = vec![];
-        let scope_map : &[Option<CodeExtent>] = &self.scope_map;
+        let mut b_vec: Vec<CodeExtent<'tcx>> = vec![];
+        let scope_map = &self.scope_map;
         let a_ancestors = ancestors_of(scope_map, scope_a, &mut a_buf, &mut a_vec);
         let b_ancestors = ancestors_of(scope_map, scope_b, &mut b_buf, &mut b_vec);
         let mut a_index = a_ancestors.len() - 1;
@@ -588,11 +512,11 @@ impl RegionMaps {
             // nesting. The reasoning behind this is subtle.  See the
             // "Modeling closures" section of the README in
             // infer::region_inference for more details.
-            let a_root_scope = self.code_extent_data(a_ancestors[a_index]);
-            let b_root_scope = self.code_extent_data(a_ancestors[a_index]);
+            let a_root_scope = a_ancestors[a_index];
+            let b_root_scope = a_ancestors[a_index];
             return match (a_root_scope, b_root_scope) {
-                (CodeExtentData::DestructionScope(a_root_id),
-                 CodeExtentData::DestructionScope(b_root_id)) => {
+                (&CodeExtentData::DestructionScope(a_root_id),
+                 &CodeExtentData::DestructionScope(b_root_id)) => {
                     if self.fn_is_enclosed_by(a_root_id, b_root_id) {
                         // `a` is enclosed by `b`, hence `b` is the ancestor of everything in `a`
                         scope_b
@@ -623,18 +547,18 @@ impl RegionMaps {
             }
         }
 
-        fn ancestors_of<'a>(scope_map: &[Option<CodeExtent>],
-                            scope: CodeExtent,
-                            buf: &'a mut [CodeExtent; 32],
-                            vec: &'a mut Vec<CodeExtent>)
-                            -> &'a [CodeExtent] {
+        fn ancestors_of<'a, 'tcx>(scope_map: &FxHashMap<CodeExtent<'tcx>, CodeExtent<'tcx>>,
+                                  scope: CodeExtent<'tcx>,
+                                  buf: &'a mut [CodeExtent<'tcx>; 32],
+                                  vec: &'a mut Vec<CodeExtent<'tcx>>)
+                                  -> &'a [CodeExtent<'tcx>] {
             // debug!("ancestors_of(scope={:?})", scope);
             let mut scope = scope;
 
             let mut i = 0;
             while i < 32 {
                 buf[i] = scope;
-                match scope_map[scope.0 as usize] {
+                match scope_map.get(&scope) {
                     Some(superscope) => scope = superscope,
                     _ => return &buf[..i+1]
                 }
@@ -645,7 +569,7 @@ impl RegionMaps {
             vec.extend_from_slice(buf);
             loop {
                 vec.push(scope);
-                match scope_map[scope.0 as usize] {
+                match scope_map.get(&scope) {
                     Some(superscope) => scope = superscope,
                     _ => return &*vec
                 }
@@ -669,7 +593,7 @@ fn record_var_lifetime(visitor: &mut RegionResolutionVisitor,
     }
 }
 
-fn resolve_block<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, blk: &'tcx hir::Block) {
+fn resolve_block<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, blk: &'tcx hir::Block) {
     debug!("resolve_block(blk.id={:?})", blk.id);
 
     let prev_cx = visitor.cx;
@@ -740,7 +664,7 @@ fn resolve_block<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, blk:
     visitor.cx = prev_cx;
 }
 
-fn resolve_arm<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, arm: &'tcx hir::Arm) {
+fn resolve_arm<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, arm: &'tcx hir::Arm) {
     visitor.terminating_scopes.insert(arm.body.id);
 
     if let Some(ref expr) = arm.guard {
@@ -750,7 +674,7 @@ fn resolve_arm<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, arm: &
     intravisit::walk_arm(visitor, arm);
 }
 
-fn resolve_pat<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, pat: &'tcx hir::Pat) {
+fn resolve_pat<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, pat: &'tcx hir::Pat) {
     visitor.new_node_extent(pat.id);
 
     // If this is a binding then record the lifetime of that binding.
@@ -761,7 +685,7 @@ fn resolve_pat<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, pat: &
     intravisit::walk_pat(visitor, pat);
 }
 
-fn resolve_stmt<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, stmt: &'tcx hir::Stmt) {
+fn resolve_stmt<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, stmt: &'tcx hir::Stmt) {
     let stmt_id = stmt.node.id();
     debug!("resolve_stmt(stmt.id={:?})", stmt_id);
 
@@ -779,7 +703,7 @@ fn resolve_stmt<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, stmt:
     visitor.cx.parent = prev_parent;
 }
 
-fn resolve_expr<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, expr: &'tcx hir::Expr) {
+fn resolve_expr<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, expr: &'tcx hir::Expr) {
     debug!("resolve_expr(expr.id={:?})", expr.id);
 
     let expr_extent = visitor.new_node_extent_with_dtor(expr.id);
@@ -857,7 +781,7 @@ fn resolve_expr<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, expr:
     visitor.cx = prev_cx;
 }
 
-fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
+fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
                            local: &'tcx hir::Local) {
     debug!("resolve_local(local.id={:?},local.init={:?})",
            local.id,local.init.is_some());
@@ -998,9 +922,11 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
     ///        | box E&
     ///        | E& as ...
     ///        | ( E& )
-    fn record_rvalue_scope_if_borrow_expr(visitor: &mut RegionResolutionVisitor,
+    fn record_rvalue_scope_if_borrow_expr<'a, 'tcx>(
+        visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
         expr: &hir::Expr,
-                                          blk_id: CodeExtent) {
+        blk_id: CodeExtent<'tcx>)
+    {
         match expr.node {
             hir::ExprAddrOf(_, ref subexpr) => {
                 record_rvalue_scope_if_borrow_expr(visitor, &subexpr, blk_id);
@@ -1047,9 +973,9 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
     ///        | <rvalue>
     ///
     /// Note: ET is intended to match "rvalues or lvalues based on rvalues".
-    fn record_rvalue_scope<'a>(visitor: &mut RegionResolutionVisitor,
-                               expr: &'a hir::Expr,
-                               blk_scope: CodeExtent,
+    fn record_rvalue_scope<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
+                                     expr: &hir::Expr,
+                                     blk_scope: CodeExtent<'tcx>,
                                      is_shrunk: bool) {
         let mut expr = expr;
         loop {
@@ -1081,10 +1007,8 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
     }
 }
 
-fn resolve_item_like<'a, 'tcx, F>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
-                                  id: ast::NodeId,
-                                  walk: F)
-    where F: FnOnce(&mut RegionResolutionVisitor<'tcx, 'a>)
+fn resolve_item_like<'a, 'tcx, F>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, walk: F)
+    where F: FnOnce(&mut RegionResolutionVisitor<'a, 'tcx>)
 {
     // Items create a new outer block scope as far as we're concerned.
     let prev_cx = visitor.cx;
@@ -1095,12 +1019,11 @@ fn resolve_item_like<'a, 'tcx, F>(visitor: &mut RegionResolutionVisitor<'tcx, 'a
         parent: None,
     };
     walk(visitor);
-    visitor.create_item_scope_if_needed(id);
     visitor.cx = prev_cx;
     visitor.terminating_scopes = prev_ts;
 }
 
-fn resolve_fn<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
+fn resolve_fn<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
                         kind: FnKind<'tcx>,
                         decl: &'tcx hir::FnDecl,
                         body_id: hir::BodyId,
@@ -1111,7 +1034,7 @@ fn resolve_fn<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
                                body.id={:?}, \
                                cx.parent={:?})",
            id,
-           visitor.sess.codemap().span_to_string(sp),
+           visitor.tcx.sess.codemap().span_to_string(sp),
            body_id,
            visitor.cx.parent);
 
@@ -1152,17 +1075,37 @@ fn resolve_fn<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
     visitor.terminating_scopes = outer_ts;
 }
 
-impl<'hir, 'a> RegionResolutionVisitor<'hir, 'a> {
-    /// Records the current parent (if any) as the parent of `child_scope`.
-    fn new_code_extent(&mut self, child_scope: CodeExtentData) -> CodeExtent {
-        self.region_maps.intern_code_extent(child_scope, self.cx.parent)
+impl<'a, 'tcx> RegionResolutionVisitor<'a, 'tcx> {
+    pub fn intern_code_extent(&mut self,
+                              data: CodeExtentData,
+                              parent: Option<CodeExtent<'tcx>>)
+                              -> CodeExtent<'tcx> {
+        let code_extent = self.tcx.intern_code_extent(data);
+        debug!("{:?}.parent = {:?}", code_extent, parent);
+        if let Some(p) = parent {
+            let prev = self.region_maps.scope_map.insert(code_extent, p);
+            assert!(prev.is_none());
+        }
+        code_extent
     }
 
-    fn new_node_extent(&mut self, child_scope: ast::NodeId) -> CodeExtent {
+    pub fn intern_node(&mut self,
+                       n: ast::NodeId,
+                       parent: Option<CodeExtent<'tcx>>) -> CodeExtent<'tcx> {
+        self.intern_code_extent(CodeExtentData::Misc(n), parent)
+    }
+
+    /// Records the current parent (if any) as the parent of `child_scope`.
+    fn new_code_extent(&mut self, child_scope: CodeExtentData) -> CodeExtent<'tcx> {
+        let parent = self.cx.parent;
+        self.intern_code_extent(child_scope, parent)
+    }
+
+    fn new_node_extent(&mut self, child_scope: ast::NodeId) -> CodeExtent<'tcx> {
         self.new_code_extent(CodeExtentData::Misc(child_scope))
     }
 
-    fn new_node_extent_with_dtor(&mut self, id: ast::NodeId) -> CodeExtent {
+    fn new_node_extent_with_dtor(&mut self, id: ast::NodeId) -> CodeExtent<'tcx> {
         // If node was previously marked as a terminating scope during the
         // recursive visit of its parent node in the AST, then we need to
         // account for the destruction scope representing the extent of
@@ -1170,101 +1113,79 @@ impl<'hir, 'a> RegionResolutionVisitor<'hir, 'a> {
         if self.terminating_scopes.contains(&id) {
             let ds = self.new_code_extent(
                 CodeExtentData::DestructionScope(id));
-            self.region_maps.intern_node(id, Some(ds))
+            self.intern_node(id, Some(ds))
         } else {
             self.new_node_extent(id)
         }
     }
-
-    fn create_item_scope_if_needed(&mut self, id: ast::NodeId) {
-        // create a region for the destruction scope - this is needed
-        // for constructing parameter environments based on the item.
-        // functions put their destruction scopes *inside* their parameter
-        // scopes.
-        let scope = CodeExtentData::DestructionScope(id);
-        if !self.region_maps.code_extent_interner.contains_key(&scope) {
-            self.region_maps.intern_code_extent(scope, None);
-        }
-    }
 }
 
-impl<'hir, 'a> Visitor<'hir> for RegionResolutionVisitor<'hir, 'a> {
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'hir> {
+impl<'a, 'tcx> Visitor<'tcx> for RegionResolutionVisitor<'a, 'tcx> {
+    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
         NestedVisitorMap::OnlyBodies(&self.map)
     }
 
-    fn visit_body(&mut self, b: &'hir Body) {
-        // make sure that every body owner has an item scope, since
-        // MIR construction wants that
-        let owner = self.map.body_owner(b.id());
-        self.create_item_scope_if_needed(owner);
-
-        intravisit::walk_body(self, b);
-    }
-
-    fn visit_block(&mut self, b: &'hir Block) {
+    fn visit_block(&mut self, b: &'tcx Block) {
         resolve_block(self, b);
     }
 
-    fn visit_item(&mut self, i: &'hir Item) {
-        resolve_item_like(self, i.id, |this| intravisit::walk_item(this, i));
+    fn visit_item(&mut self, i: &'tcx Item) {
+        resolve_item_like(self, |this| intravisit::walk_item(this, i));
     }
 
-    fn visit_impl_item(&mut self, ii: &'hir hir::ImplItem) {
-        resolve_item_like(self, ii.id, |this| intravisit::walk_impl_item(this, ii));
+    fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
+        resolve_item_like(self, |this| intravisit::walk_impl_item(this, ii));
     }
 
-    fn visit_trait_item(&mut self, ti: &'hir hir::TraitItem) {
-        resolve_item_like(self, ti.id, |this| intravisit::walk_trait_item(this, ti));
+    fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
+        resolve_item_like(self, |this| intravisit::walk_trait_item(this, ti));
     }
 
-    fn visit_fn(&mut self, fk: FnKind<'hir>, fd: &'hir FnDecl,
+    fn visit_fn(&mut self, fk: FnKind<'tcx>, fd: &'tcx FnDecl,
                 b: hir::BodyId, s: Span, n: NodeId) {
         resolve_fn(self, fk, fd, b, s, n);
     }
-    fn visit_arm(&mut self, a: &'hir Arm) {
+    fn visit_arm(&mut self, a: &'tcx Arm) {
         resolve_arm(self, a);
     }
-    fn visit_pat(&mut self, p: &'hir Pat) {
+    fn visit_pat(&mut self, p: &'tcx Pat) {
         resolve_pat(self, p);
     }
-    fn visit_stmt(&mut self, s: &'hir Stmt) {
+    fn visit_stmt(&mut self, s: &'tcx Stmt) {
         resolve_stmt(self, s);
     }
-    fn visit_expr(&mut self, ex: &'hir Expr) {
+    fn visit_expr(&mut self, ex: &'tcx Expr) {
         resolve_expr(self, ex);
     }
-    fn visit_local(&mut self, l: &'hir Local) {
+    fn visit_local(&mut self, l: &'tcx Local) {
         resolve_local(self, l);
     }
 }
 
-pub fn resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Rc<RegionMaps> {
+pub fn resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Rc<RegionMaps<'tcx>> {
     tcx.region_resolve_crate(LOCAL_CRATE)
 }
 
 fn region_resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum)
-    -> Rc<RegionMaps>
+    -> Rc<RegionMaps<'tcx>>
 {
     debug_assert!(crate_num == LOCAL_CRATE);
 
-    let sess = &tcx.sess;
     let hir_map = &tcx.hir;
 
     let krate = hir_map.krate();
 
     let mut maps = RegionMaps {
-        code_extents: vec![],
-        code_extent_interner: FxHashMap(),
-        scope_map: vec![],
+        scope_map: FxHashMap(),
         var_map: NodeMap(),
         rvalue_scopes: NodeMap(),
         shrunk_rvalue_scopes: NodeMap(),
         fn_tree: NodeMap(),
     };
+
     {
         let mut visitor = RegionResolutionVisitor {
-            sess: sess,
+            tcx: tcx,
             region_maps: &mut maps,
             map: hir_map,
             cx: Context {

src/librustc/mir/mod.rs

@@ -1034,7 +1034,7 @@ pub enum Rvalue<'tcx> {
     Repeat(Operand<'tcx>, ConstUsize),
 
     /// &x or &mut x
-    Ref(&'tcx Region, BorrowKind, Lvalue<'tcx>),
+    Ref(Region<'tcx>, BorrowKind, Lvalue<'tcx>),
 
     /// length of a [X] or [X;n] value
     Len(Lvalue<'tcx>),

src/librustc/mir/visit.rs

@@ -747,7 +747,7 @@ pub enum LvalueContext<'tcx> {
     Inspect,
 
     // Being borrowed
-    Borrow { region: &'tcx Region, kind: BorrowKind },
+    Borrow { region: Region<'tcx>, kind: BorrowKind },
 
     // Used as base for another lvalue, e.g. `x` in `x.y`.
     //

src/librustc/traits/fulfill.rs

@@ -84,7 +84,7 @@ pub struct FulfillmentContext<'tcx> {
 
 #[derive(Clone)]
 pub struct RegionObligation<'tcx> {
-    pub sub_region: &'tcx ty::Region,
+    pub sub_region: ty::Region<'tcx>,
     pub sup_type: Ty<'tcx>,
     pub cause: ObligationCause<'tcx>,
 }
@@ -155,7 +155,7 @@ impl<'a, 'gcx, 'tcx> FulfillmentContext<'tcx> {
 
     pub fn register_region_obligation(&mut self,
                                       t_a: Ty<'tcx>,
-                                      r_b: &'tcx ty::Region,
+                                      r_b: ty::Region<'tcx>,
                                       cause: ObligationCause<'tcx>)
     {
         register_region_obligation(t_a, r_b, cause, &mut self.region_obligations);
@@ -566,7 +566,7 @@ fn coinductive_obligation<'a,'gcx,'tcx>(selcx: &SelectionContext<'a,'gcx,'tcx>,
 }
 
 fn register_region_obligation<'tcx>(t_a: Ty<'tcx>,
-                                    r_b: &'tcx ty::Region,
+                                    r_b: ty::Region<'tcx>,
                                     cause: ObligationCause<'tcx>,
                                     region_obligations: &mut NodeMap<Vec<RegionObligation<'tcx>>>)
 {

src/librustc/traits/mod.rs

@@ -112,7 +112,7 @@ pub enum ObligationCauseCode<'tcx> {
     ReferenceOutlivesReferent(Ty<'tcx>),
 
     /// A type like `Box<Foo<'a> + 'b>` is WF only if `'b: 'a`.
-    ObjectTypeBound(Ty<'tcx>, &'tcx ty::Region),
+    ObjectTypeBound(Ty<'tcx>, ty::Region<'tcx>),
 
     /// Obligation incurred due to an object cast.
     ObjectCastObligation(/* Object type */ Ty<'tcx>),

src/librustc/ty/_match.rs

@@ -52,8 +52,8 @@ impl<'a, 'gcx, 'tcx> TypeRelation<'a, 'gcx, 'tcx> for Match<'a, 'gcx, 'tcx> {
         self.relate(a, b)
     }
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region> {
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})",
                self.tag(),
                a,

src/librustc/ty/adjustment.rs

@@ -133,7 +133,7 @@ impl<'tcx> Adjustment<'tcx> {
 #[derive(Copy, Clone, PartialEq, Debug, RustcEncodable, RustcDecodable)]
 pub enum AutoBorrow<'tcx> {
     /// Convert from T to &T.
-    Ref(&'tcx ty::Region, hir::Mutability),
+    Ref(ty::Region<'tcx>, hir::Mutability),
 
     /// Convert from T to *T.
     RawPtr(hir::Mutability),

src/librustc/ty/context.rs

@@ -21,7 +21,7 @@ use hir::map as hir_map;
 use hir::map::DisambiguatedDefPathData;
 use middle::free_region::FreeRegionMap;
 use middle::lang_items;
-use middle::region::RegionMaps;
+use middle::region::{CodeExtent, CodeExtentData, RegionMaps};
 use middle::resolve_lifetime;
 use middle::stability;
 use mir::Mir;
@@ -33,6 +33,7 @@ use ty::{TyS, TypeVariants, Slice};
 use ty::{AdtKind, AdtDef, ClosureSubsts, Region};
 use hir::FreevarMap;
 use ty::{PolyFnSig, InferTy, ParamTy, ProjectionTy, ExistentialPredicate};
+use ty::RegionKind;
 use ty::{TyVar, TyVid, IntVar, IntVid, FloatVar, FloatVid};
 use ty::TypeVariants::*;
 use ty::layout::{Layout, TargetDataLayout};
@@ -94,7 +95,7 @@ pub struct CtxtInterners<'tcx> {
     type_: RefCell<FxHashSet<Interned<'tcx, TyS<'tcx>>>>,
     type_list: RefCell<FxHashSet<Interned<'tcx, Slice<Ty<'tcx>>>>>,
     substs: RefCell<FxHashSet<Interned<'tcx, Substs<'tcx>>>>,
-    region: RefCell<FxHashSet<Interned<'tcx, Region>>>,
+    region: RefCell<FxHashSet<Interned<'tcx, RegionKind<'tcx>>>>,
     existential_predicates: RefCell<FxHashSet<Interned<'tcx, Slice<ExistentialPredicate<'tcx>>>>>,
 }
 
@@ -192,9 +193,9 @@ pub struct CommonTypes<'tcx> {
     pub never: Ty<'tcx>,
     pub err: Ty<'tcx>,
 
-    pub re_empty: &'tcx Region,
-    pub re_static: &'tcx Region,
-    pub re_erased: &'tcx Region,
+    pub re_empty: Region<'tcx>,
+    pub re_static: Region<'tcx>,
+    pub re_erased: Region<'tcx>,
 }
 
 #[derive(RustcEncodable, RustcDecodable)]
@@ -257,7 +258,7 @@ pub struct TypeckTables<'tcx> {
     /// Stores the free-region relationships that were deduced from
     /// its where clauses and parameter types. These are then
     /// read-again by borrowck.
-    pub free_region_map: FreeRegionMap,
+    pub free_region_map: FreeRegionMap<'tcx>,
 }
 
 impl<'tcx> TypeckTables<'tcx> {
@@ -393,9 +394,9 @@ impl<'tcx> CommonTypes<'tcx> {
             f32: mk(TyFloat(ast::FloatTy::F32)),
             f64: mk(TyFloat(ast::FloatTy::F64)),
 
-            re_empty: mk_region(Region::ReEmpty),
-            re_static: mk_region(Region::ReStatic),
-            re_erased: mk_region(Region::ReErased),
+            re_empty: mk_region(RegionKind::ReEmpty),
+            re_static: mk_region(RegionKind::ReStatic),
+            re_erased: mk_region(RegionKind::ReErased),
         }
     }
 }
@@ -549,6 +550,8 @@ pub struct GlobalCtxt<'tcx> {
 
     layout_interner: RefCell<FxHashSet<&'tcx Layout>>,
 
+    code_extent_interner: RefCell<FxHashSet<CodeExtent<'tcx>>>,
+
     /// A vector of every trait accessible in the whole crate
     /// (i.e. including those from subcrates). This is used only for
     /// error reporting, and so is lazily initialised and generally
@@ -649,6 +652,38 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         interned
     }
 
+    pub fn node_extent(self, n: ast::NodeId) -> CodeExtent<'gcx> {
+        self.intern_code_extent(CodeExtentData::Misc(n))
+    }
+
+    // TODO this is revealing side-effects of query, bad
+    pub fn opt_destruction_extent(self, n: ast::NodeId) -> Option<CodeExtent<'gcx>> {
+        let s = CodeExtentData::DestructionScope(n);
+        self.code_extent_interner.borrow().get(&s).cloned()
+    }
+
+    // Returns the code extent for an item - the destruction scope.
+    pub fn item_extent(self, n: ast::NodeId) -> CodeExtent<'gcx> {
+        self.intern_code_extent(CodeExtentData::DestructionScope(n))
+    }
+
+    pub fn call_site_extent(self, fn_id: ast::NodeId, body_id: ast::NodeId) -> CodeExtent<'gcx> {
+        assert!(fn_id != body_id);
+        self.intern_code_extent(CodeExtentData::CallSiteScope { fn_id: fn_id, body_id: body_id })
+    }
+
+    pub fn intern_code_extent(self, data: CodeExtentData) -> CodeExtent<'gcx> {
+        if let Some(st) = self.code_extent_interner.borrow().get(&data) {
+            return st;
+        }
+
+        let interned = self.global_interners.arena.alloc(data);
+        if let Some(prev) = self.code_extent_interner.borrow_mut().replace(interned) {
+            bug!("Tried to overwrite interned code-extent: {:?}", prev)
+        }
+        interned
+    }
+
     pub fn intern_layout(self, layout: Layout) -> &'gcx Layout {
         if let Some(layout) = self.layout_interner.borrow().get(&layout) {
             return layout;
@@ -677,7 +712,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         local as usize == global as usize
     }
 
-    pub fn region_maps(self) -> Rc<RegionMaps> {
+    pub fn region_maps(self) -> Rc<RegionMaps<'tcx>> {
         self.region_resolve_crate(LOCAL_CRATE)
     }
 
@@ -741,6 +776,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             data_layout: data_layout,
             layout_cache: RefCell::new(FxHashMap()),
             layout_interner: RefCell::new(FxHashSet()),
+            code_extent_interner: RefCell::new(FxHashSet()),
             layout_depth: Cell::new(0),
             derive_macros: RefCell::new(NodeMap()),
             stability_interner: RefCell::new(FxHashSet()),
@@ -820,9 +856,18 @@ impl<'a, 'tcx> Lift<'tcx> for &'a Substs<'a> {
     }
 }
 
-impl<'a, 'tcx> Lift<'tcx> for &'a Region {
-    type Lifted = &'tcx Region;
-    fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<&'tcx Region> {
+impl<'a, 'tcx> Lift<'tcx> for ty::FreeRegion<'a> {
+    type Lifted = ty::FreeRegion<'tcx>;
+    fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
+        let scope = self.scope.map(|code_extent| tcx.intern_code_extent(*code_extent));
+        let bound_region = self.bound_region;
+        Some(ty::FreeRegion { scope, bound_region })
+    }
+}
+
+impl<'a, 'tcx> Lift<'tcx> for Region<'a> {
+    type Lifted = Region<'tcx>;
+    fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Region<'tcx>> {
         if tcx.interners.arena.in_arena(*self as *const _) {
             return Some(unsafe { mem::transmute(*self) });
         }
@@ -1083,9 +1128,9 @@ impl<'tcx: 'lcx, 'lcx> Borrow<[Kind<'lcx>]> for Interned<'tcx, Substs<'tcx>> {
     }
 }
 
-impl<'tcx> Borrow<Region> for Interned<'tcx, Region> {
-    fn borrow<'a>(&'a self) -> &'a Region {
-        self.0
+impl<'tcx> Borrow<RegionKind<'tcx>> for Interned<'tcx, RegionKind<'tcx>> {
+    fn borrow<'a>(&'a self) -> &'a RegionKind<'tcx> {
+        &self.0
     }
 }
 
@@ -1176,7 +1221,7 @@ direct_interners!('tcx,
             &ty::ReVar(_) | &ty::ReSkolemized(..) => true,
             _ => false
         }
-    }) -> Region
+    }) -> RegionKind<'tcx>
 );
 
 macro_rules! slice_interners {
@@ -1268,15 +1313,15 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.mk_ty(TyRawPtr(tm))
     }
 
-    pub fn mk_ref(self, r: &'tcx Region, tm: TypeAndMut<'tcx>) -> Ty<'tcx> {
+    pub fn mk_ref(self, r: Region<'tcx>, tm: TypeAndMut<'tcx>) -> Ty<'tcx> {
         self.mk_ty(TyRef(r, tm))
     }
 
-    pub fn mk_mut_ref(self, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
+    pub fn mk_mut_ref(self, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutMutable})
     }
 
-    pub fn mk_imm_ref(self, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
+    pub fn mk_imm_ref(self, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
         self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutImmutable})
     }
 
@@ -1338,7 +1383,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn mk_dynamic(
         self,
         obj: ty::Binder<&'tcx Slice<ExistentialPredicate<'tcx>>>,
-        reg: &'tcx ty::Region
+        reg: ty::Region<'tcx>
     ) -> Ty<'tcx> {
         self.mk_ty(TyDynamic(obj, reg))
     }

src/librustc/ty/error.rs

@@ -36,11 +36,11 @@ pub enum TypeError<'tcx> {
     TupleSize(ExpectedFound<usize>),
     FixedArraySize(ExpectedFound<usize>),
     ArgCount,
-    RegionsDoesNotOutlive(&'tcx Region, &'tcx Region),
-    RegionsNotSame(&'tcx Region, &'tcx Region),
-    RegionsNoOverlap(&'tcx Region, &'tcx Region),
-    RegionsInsufficientlyPolymorphic(BoundRegion, &'tcx Region, Option<Box<ty::Issue32330>>),
-    RegionsOverlyPolymorphic(BoundRegion, &'tcx Region, Option<Box<ty::Issue32330>>),
+    RegionsDoesNotOutlive(Region<'tcx>, Region<'tcx>),
+    RegionsNotSame(Region<'tcx>, Region<'tcx>),
+    RegionsNoOverlap(Region<'tcx>, Region<'tcx>),
+    RegionsInsufficientlyPolymorphic(BoundRegion, Region<'tcx>, Option<Box<ty::Issue32330>>),
+    RegionsOverlyPolymorphic(BoundRegion, Region<'tcx>, Option<Box<ty::Issue32330>>),
     Sorts(ExpectedFound<Ty<'tcx>>),
     IntMismatch(ExpectedFound<ty::IntVarValue>),
     FloatMismatch(ExpectedFound<ast::FloatTy>),

src/librustc/ty/flags.rs

@@ -186,7 +186,7 @@ impl FlagComputation {
         self.add_bound_computation(&computation);
     }
 
-    fn add_region(&mut self, r: &ty::Region) {
+    fn add_region(&mut self, r: ty::Region) {
         self.add_flags(r.type_flags());
         if let ty::ReLateBound(debruijn, _) = *r {
             self.add_depth(debruijn.depth);

src/librustc/ty/fold.rs

@@ -159,7 +159,7 @@ pub trait TypeFolder<'gcx: 'tcx, 'tcx> : Sized {
         sig.super_fold_with(self)
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         r.super_fold_with(self)
     }
 
@@ -182,7 +182,7 @@ pub trait TypeVisitor<'tcx> : Sized {
         trait_ref.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         r.super_visit_with(self)
     }
 }
@@ -216,7 +216,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// whether any late-bound regions were skipped
     pub fn collect_regions<T>(self,
         value: &T,
-        region_set: &mut FxHashSet<&'tcx ty::Region>)
+        region_set: &mut FxHashSet<ty::Region<'tcx>>)
         -> bool
         where T : TypeFoldable<'tcx>
     {
@@ -236,7 +236,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         skipped_regions: &mut bool,
         mut f: F)
         -> T
-        where F : FnMut(&'tcx ty::Region, u32) -> &'tcx ty::Region,
+        where F : FnMut(ty::Region<'tcx>, u32) -> ty::Region<'tcx>,
               T : TypeFoldable<'tcx>,
     {
         value.fold_with(&mut RegionFolder::new(self, skipped_regions, &mut f))
@@ -256,14 +256,14 @@ pub struct RegionFolder<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
     skipped_regions: &'a mut bool,
     current_depth: u32,
-    fld_r: &'a mut (FnMut(&'tcx ty::Region, u32) -> &'tcx ty::Region + 'a),
+    fld_r: &'a mut (FnMut(ty::Region<'tcx>, u32) -> ty::Region<'tcx> + 'a),
 }
 
 impl<'a, 'gcx, 'tcx> RegionFolder<'a, 'gcx, 'tcx> {
     pub fn new<F>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                   skipped_regions: &'a mut bool,
                   fld_r: &'a mut F) -> RegionFolder<'a, 'gcx, 'tcx>
-        where F : FnMut(&'tcx ty::Region, u32) -> &'tcx ty::Region
+        where F : FnMut(ty::Region<'tcx>, u32) -> ty::Region<'tcx>
     {
         RegionFolder {
             tcx: tcx,
@@ -284,7 +284,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionFolder<'a, 'gcx, 'tcx> {
         t
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReLateBound(debruijn, _) if debruijn.depth < self.current_depth => {
                 debug!("RegionFolder.fold_region({:?}) skipped bound region (current depth={})",
@@ -309,16 +309,16 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionFolder<'a, 'gcx, 'tcx> {
 struct RegionReplacer<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
     current_depth: u32,
-    fld_r: &'a mut (FnMut(ty::BoundRegion) -> &'tcx ty::Region + 'a),
-    map: FxHashMap<ty::BoundRegion, &'tcx ty::Region>
+    fld_r: &'a mut (FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a),
+    map: FxHashMap<ty::BoundRegion, ty::Region<'tcx>>
 }
 
 impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn replace_late_bound_regions<T,F>(self,
         value: &Binder<T>,
         mut f: F)
-        -> (T, FxHashMap<ty::BoundRegion, &'tcx ty::Region>)
-        where F : FnMut(ty::BoundRegion) -> &'tcx ty::Region,
+        -> (T, FxHashMap<ty::BoundRegion, ty::Region<'tcx>>)
+        where F : FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
               T : TypeFoldable<'tcx>,
     {
         let mut replacer = RegionReplacer::new(self, &mut f);
@@ -330,7 +330,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
     /// `scope_id`.
     pub fn liberate_late_bound_regions<T>(self,
-        all_outlive_scope: Option<region::CodeExtent>,
+        all_outlive_scope: Option<region::CodeExtent<'tcx>>,
         value: &Binder<T>)
         -> T
         where T : TypeFoldable<'tcx>
@@ -435,7 +435,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 impl<'a, 'gcx, 'tcx> RegionReplacer<'a, 'gcx, 'tcx> {
     fn new<F>(tcx: TyCtxt<'a, 'gcx, 'tcx>, fld_r: &'a mut F)
               -> RegionReplacer<'a, 'gcx, 'tcx>
-        where F : FnMut(ty::BoundRegion) -> &'tcx ty::Region
+        where F : FnMut(ty::BoundRegion) -> ty::Region<'tcx>
     {
         RegionReplacer {
             tcx: tcx,
@@ -464,7 +464,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionReplacer<'a, 'gcx, 'tcx> {
         t.super_fold_with(self)
     }
 
-    fn fold_region(&mut self, r:&'tcx  ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match *r {
             ty::ReLateBound(debruijn, br) if debruijn.depth == self.current_depth => {
                 let fld_r = &mut self.fld_r;
@@ -527,7 +527,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 u.super_fold_with(self)
             }
 
-            fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+            fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
                 // because late-bound regions affect subtyping, we can't
                 // erase the bound/free distinction, but we can replace
                 // all free regions with 'erased.
@@ -554,7 +554,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 // regions. See comment on `shift_regions_through_binders` method in
 // `subst.rs` for more details.
 
-pub fn shift_region(region: ty::Region, amount: u32) -> ty::Region {
+pub fn shift_region<'tcx>(region: ty::RegionKind<'tcx>, amount: u32) -> ty::RegionKind<'tcx> {
     match region {
         ty::ReLateBound(debruijn, br) => {
             ty::ReLateBound(debruijn.shifted(amount), br)
@@ -567,9 +567,9 @@ pub fn shift_region(region: ty::Region, amount: u32) -> ty::Region {
 
 pub fn shift_region_ref<'a, 'gcx, 'tcx>(
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
-    region: &'tcx ty::Region,
+    region: ty::Region<'tcx>,
     amount: u32)
-    -> &'tcx ty::Region
+    -> ty::Region<'tcx>
 {
     match region {
         &ty::ReLateBound(debruijn, br) if amount > 0 => {
@@ -582,7 +582,8 @@ pub fn shift_region_ref<'a, 'gcx, 'tcx>(
 }
 
 pub fn shift_regions<'a, 'gcx, 'tcx, T>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
-                                        amount: u32, value: &T) -> T
+                                        amount: u32,
+                                        value: &T) -> T
     where T: TypeFoldable<'tcx>
 {
     debug!("shift_regions(value={:?}, amount={})",
@@ -631,7 +632,7 @@ impl<'tcx> TypeVisitor<'tcx> for HasEscapingRegionsVisitor {
         t.region_depth > self.depth
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         r.escapes_depth(self.depth)
     }
 }
@@ -647,7 +648,7 @@ impl<'tcx> TypeVisitor<'tcx> for HasTypeFlagsVisitor {
         flags.intersects(self.flags)
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         let flags = r.type_flags();
         debug!("HasTypeFlagsVisitor: r={:?} r.flags={:?} self.flags={:?}", r, flags, self.flags);
         flags.intersects(self.flags)
@@ -693,7 +694,7 @@ impl<'tcx> TypeVisitor<'tcx> for LateBoundRegionsCollector {
         t.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         match *r {
             ty::ReLateBound(debruijn, br) if debruijn.depth == self.current_depth => {
                 self.regions.insert(br);

src/librustc/ty/maps.rs

@@ -578,7 +578,7 @@ define_maps! { <'tcx>
 
     [] reachable_set: reachability_dep_node(CrateNum) -> Rc<NodeSet>,
 
-    [] region_resolve_crate: region_resolve_crate_dep_node(CrateNum) -> Rc<RegionMaps>,
+    [] region_resolve_crate: region_resolve_crate_dep_node(CrateNum) -> Rc<RegionMaps<'tcx>>,
 
     [] mir_shims: mir_shim_dep_node(ty::InstanceDef<'tcx>) -> &'tcx RefCell<mir::Mir<'tcx>>,
 

src/librustc/ty/mod.rs

@@ -67,11 +67,12 @@ pub use self::sty::{TraitRef, TypeVariants, PolyTraitRef};
 pub use self::sty::{ExistentialTraitRef, PolyExistentialTraitRef};
 pub use self::sty::{ExistentialProjection, PolyExistentialProjection};
 pub use self::sty::{BoundRegion, EarlyBoundRegion, FreeRegion, Region};
+pub use self::sty::RegionKind;
 pub use self::sty::Issue32330;
 pub use self::sty::{TyVid, IntVid, FloatVid, RegionVid, SkolemizedRegionVid};
 pub use self::sty::BoundRegion::*;
 pub use self::sty::InferTy::*;
-pub use self::sty::Region::*;
+pub use self::sty::RegionKind::*;
 pub use self::sty::TypeVariants::*;
 
 pub use self::context::{TyCtxt, GlobalArenas, tls};
@@ -601,7 +602,7 @@ pub struct UpvarBorrow<'tcx> {
     pub kind: BorrowKind,
 
     /// Region of the resulting reference.
-    pub region: &'tcx ty::Region,
+    pub region: ty::Region<'tcx>,
 }
 
 pub type UpvarCaptureMap<'tcx> = FxHashMap<UpvarId, UpvarCapture<'tcx>>;
@@ -934,9 +935,9 @@ pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
 #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
-pub type PolyRegionOutlivesPredicate<'tcx> = PolyOutlivesPredicate<&'tcx ty::Region,
-                                                                   &'tcx ty::Region>;
-pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, &'tcx ty::Region>;
+pub type PolyRegionOutlivesPredicate<'tcx> = PolyOutlivesPredicate<ty::Region<'tcx>,
+                                                                   ty::Region<'tcx>>;
+pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>;
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct SubtypePredicate<'tcx> {
@@ -1167,7 +1168,7 @@ pub struct ParameterEnvironment<'tcx> {
     /// region of the callee. If it is `None`, then the parameter
     /// environment is for an item or something where the "callee" is
     /// not clear.
-    pub implicit_region_bound: Option<&'tcx ty::Region>,
+    pub implicit_region_bound: Option<ty::Region<'tcx>>,
 
     /// Obligations that the caller must satisfy. This is basically
     /// the set of bounds on the in-scope type parameters, translated
@@ -1181,7 +1182,7 @@ pub struct ParameterEnvironment<'tcx> {
     /// FIXME(#3696). It would be nice to refactor so that free
     /// regions don't have this implicit scope and instead introduce
     /// relationships in the environment.
-    pub free_id_outlive: Option<CodeExtent>,
+    pub free_id_outlive: Option<CodeExtent<'tcx>>,
 
     /// A cache for `moves_by_default`.
     pub is_copy_cache: RefCell<FxHashMap<Ty<'tcx>, bool>>,
@@ -1222,13 +1223,13 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                         let impl_def_id = tcx.hir.local_def_id(impl_id);
                         tcx.construct_parameter_environment(impl_item.span,
                                                             impl_def_id,
-                                                            Some(tcx.region_maps().item_extent(id)))
+                                                            Some(tcx.item_extent(id)))
                     }
                     hir::ImplItemKind::Method(_, ref body) => {
                         tcx.construct_parameter_environment(
                             impl_item.span,
                             tcx.hir.local_def_id(id),
-                            Some(tcx.region_maps().call_site_extent(id, body.node_id)))
+                            Some(tcx.call_site_extent(id, body.node_id)))
                     }
                 }
             }
@@ -1241,7 +1242,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                         let trait_def_id = tcx.hir.local_def_id(trait_id);
                         tcx.construct_parameter_environment(trait_item.span,
                                                             trait_def_id,
-                                                            Some(tcx.region_maps().item_extent(id)))
+                                                            Some(tcx.item_extent(id)))
                     }
                     hir::TraitItemKind::Method(_, ref body) => {
                         // Use call-site for extent (unless this is a
@@ -1249,10 +1250,10 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                         // to the method id).
                         let extent = if let hir::TraitMethod::Provided(body_id) = *body {
                             // default impl: use call_site extent as free_id_outlive bound.
-                            tcx.region_maps().call_site_extent(id, body_id.node_id)
+                            tcx.call_site_extent(id, body_id.node_id)
                         } else {
                             // no default impl: use item extent as free_id_outlive bound.
-                            tcx.region_maps().item_extent(id)
+                            tcx.item_extent(id)
                         };
                         tcx.construct_parameter_environment(
                             trait_item.span,
@@ -1270,7 +1271,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                         tcx.construct_parameter_environment(
                             item.span,
                             fn_def_id,
-                            Some(tcx.region_maps().call_site_extent(id, body_id.node_id)))
+                            Some(tcx.call_site_extent(id, body_id.node_id)))
                     }
                     hir::ItemEnum(..) |
                     hir::ItemStruct(..) |
@@ -1282,13 +1283,13 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                         let def_id = tcx.hir.local_def_id(id);
                         tcx.construct_parameter_environment(item.span,
                                                             def_id,
-                                                            Some(tcx.region_maps().item_extent(id)))
+                                                            Some(tcx.item_extent(id)))
                     }
                     hir::ItemTrait(..) => {
                         let def_id = tcx.hir.local_def_id(id);
                         tcx.construct_parameter_environment(item.span,
                                                             def_id,
-                                                            Some(tcx.region_maps().item_extent(id)))
+                                                            Some(tcx.item_extent(id)))
                     }
                     _ => {
                         span_bug!(item.span,
@@ -1306,7 +1307,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                     tcx.construct_parameter_environment(
                         expr.span,
                         base_def_id,
-                        Some(tcx.region_maps().call_site_extent(id, body.node_id)))
+                        Some(tcx.call_site_extent(id, body.node_id)))
                 } else {
                     tcx.empty_parameter_environment()
                 }
@@ -2454,8 +2455,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// In general, this means converting from bound parameters to
     /// free parameters. Since we currently represent bound/free type
     /// parameters in the same way, this only has an effect on regions.
-    pub fn construct_free_substs(self, def_id: DefId,
-                                 free_id_outlive: Option<CodeExtent>)
+    pub fn construct_free_substs(self,
+                                 def_id: DefId,
+                                 free_id_outlive: Option<CodeExtent<'gcx>>)
                                  -> &'gcx Substs<'gcx> {
 
         let substs = Substs::for_item(self.global_tcx(), def_id, |def, _| {
@@ -2479,7 +2481,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn construct_parameter_environment(self,
                                            span: Span,
                                            def_id: DefId,
-                                           free_id_outlive: Option<CodeExtent>)
+                                           free_id_outlive: Option<CodeExtent<'gcx>>)
                                            -> ParameterEnvironment<'gcx>
     {
         //
@@ -2521,14 +2523,14 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             is_freeze_cache: RefCell::new(FxHashMap()),
         };
 
-        let body_id = free_id_outlive.map(|f| f.node_id(&self.region_maps()))
+        let body_id = free_id_outlive.map(|f| f.node_id())
                                      .unwrap_or(DUMMY_NODE_ID);
         let cause = traits::ObligationCause::misc(span, body_id);
         traits::normalize_param_env_or_error(tcx, unnormalized_env, cause)
     }
 
-    pub fn node_scope_region(self, id: NodeId) -> &'tcx Region {
-        self.mk_region(ty::ReScope(self.region_maps().node_extent(id)))
+    pub fn node_scope_region(self, id: NodeId) -> Region<'tcx> {
+        self.mk_region(ty::ReScope(self.node_extent(id)))
     }
 
     pub fn visit_all_item_likes_in_krate<V,F>(self,

src/librustc/ty/outlives.rs

@@ -16,7 +16,7 @@ use ty::{self, Ty, TyCtxt, TypeFoldable};
 
 #[derive(Debug)]
 pub enum Component<'tcx> {
-    Region(&'tcx ty::Region),
+    Region(ty::Region<'tcx>),
     Param(ty::ParamTy),
     UnresolvedInferenceVariable(ty::InferTy),
 
@@ -202,7 +202,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 }
 
-fn push_region_constraints<'tcx>(out: &mut Vec<Component<'tcx>>, regions: Vec<&'tcx ty::Region>) {
+fn push_region_constraints<'tcx>(out: &mut Vec<Component<'tcx>>, regions: Vec<ty::Region<'tcx>>) {
     for r in regions {
         if !r.is_bound() {
             out.push(Component::Region(r));

src/librustc/ty/relate.rs

@@ -67,8 +67,8 @@ pub trait TypeRelation<'a, 'gcx: 'a+'tcx, 'tcx: 'a> : Sized {
     fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>)
            -> RelateResult<'tcx, Ty<'tcx>>;
 
-    fn regions(&mut self, a: &'tcx ty::Region, b: &'tcx ty::Region)
-               -> RelateResult<'tcx, &'tcx ty::Region>;
+    fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)
+               -> RelateResult<'tcx, ty::Region<'tcx>>;
 
     fn binders<T>(&mut self, a: &ty::Binder<T>, b: &ty::Binder<T>)
                   -> RelateResult<'tcx, ty::Binder<T>>
@@ -529,11 +529,11 @@ impl<'tcx> Relate<'tcx> for &'tcx Substs<'tcx> {
     }
 }
 
-impl<'tcx> Relate<'tcx> for &'tcx ty::Region {
+impl<'tcx> Relate<'tcx> for ty::Region<'tcx> {
     fn relate<'a, 'gcx, R>(relation: &mut R,
-                           a: &&'tcx ty::Region,
-                           b: &&'tcx ty::Region)
-                           -> RelateResult<'tcx, &'tcx ty::Region>
+                           a: &ty::Region<'tcx>,
+                           b: &ty::Region<'tcx>)
+                           -> RelateResult<'tcx, ty::Region<'tcx>>
         where R: TypeRelation<'a, 'gcx, 'tcx>, 'gcx: 'a+'tcx, 'tcx: 'a
     {
         relation.regions(*a, *b)

src/librustc/ty/structural_impls.rs

@@ -624,7 +624,7 @@ impl<'tcx> TypeFoldable<'tcx> for ty::ImplHeader<'tcx> {
     }
 }
 
-impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Region {
+impl<'tcx> TypeFoldable<'tcx> for ty::Region<'tcx> {
     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, _folder: &mut F) -> Self {
         *self
     }

src/librustc/ty/sty.rs

@@ -47,8 +47,8 @@ pub struct TypeAndMut<'tcx> {
 /// If `fr.scope` is None, then this is in some context (e.g., an
 /// impl) where lifetimes are more abstract and the notion of the
 /// caller/callee stack frames are not applicable.
-pub struct FreeRegion {
-    pub scope: Option<region::CodeExtent>,
+pub struct FreeRegion<'tcx> {
+    pub scope: Option<region::CodeExtent<'tcx>>,
     pub bound_region: BoundRegion,
 }
 
@@ -128,7 +128,7 @@ pub enum TypeVariants<'tcx> {
 
     /// A reference; a pointer with an associated lifetime. Written as
     /// `&'a mut T` or `&'a T`.
-    TyRef(&'tcx Region, TypeAndMut<'tcx>),
+    TyRef(Region<'tcx>, TypeAndMut<'tcx>),
 
     /// The anonymous type of a function declaration/definition. Each
     /// function has a unique type.
@@ -140,7 +140,7 @@ pub enum TypeVariants<'tcx> {
     TyFnPtr(PolyFnSig<'tcx>),
 
     /// A trait, defined with `trait`.
-    TyDynamic(Binder<&'tcx Slice<ExistentialPredicate<'tcx>>>, &'tcx ty::Region),
+    TyDynamic(Binder<&'tcx Slice<ExistentialPredicate<'tcx>>>, ty::Region<'tcx>),
 
     /// The anonymous type of a closure. Used to represent the type of
     /// `|a| a`.
@@ -679,6 +679,8 @@ pub struct DebruijnIndex {
     pub depth: u32,
 }
 
+pub type Region<'tcx> = &'tcx RegionKind<'tcx>;
+
 /// Representation of regions.
 ///
 /// Unlike types, most region variants are "fictitious", not concrete,
@@ -736,7 +738,7 @@ pub struct DebruijnIndex {
 /// [1] http://smallcultfollowing.com/babysteps/blog/2013/10/29/intermingled-parameter-lists/
 /// [2] http://smallcultfollowing.com/babysteps/blog/2013/11/04/intermingled-parameter-lists/
 #[derive(Clone, PartialEq, Eq, Hash, Copy, RustcEncodable, RustcDecodable)]
-pub enum Region {
+pub enum RegionKind<'tcx> {
     // Region bound in a type or fn declaration which will be
     // substituted 'early' -- that is, at the same time when type
     // parameters are substituted.
@@ -749,12 +751,12 @@ pub enum Region {
     /// When checking a function body, the types of all arguments and so forth
     /// that refer to bound region parameters are modified to refer to free
     /// region parameters.
-    ReFree(FreeRegion),
+    ReFree(FreeRegion<'tcx>),
 
     /// A concrete region naming some statically determined extent
     /// (e.g. an expression or sequence of statements) within the
     /// current function.
-    ReScope(region::CodeExtent),
+    ReScope(region::CodeExtent<'tcx>),
 
     /// Static data that has an "infinite" lifetime. Top in the region lattice.
     ReStatic,
@@ -779,7 +781,7 @@ pub enum Region {
     ReErased,
 }
 
-impl<'tcx> serialize::UseSpecializedDecodable for &'tcx Region {}
+impl<'tcx> serialize::UseSpecializedDecodable for Region<'tcx> {}
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
 pub struct EarlyBoundRegion {
@@ -898,7 +900,7 @@ impl DebruijnIndex {
 }
 
 // Region utilities
-impl Region {
+impl<'tcx> RegionKind<'tcx> {
     pub fn is_bound(&self) -> bool {
         match *self {
             ty::ReEarlyBound(..) => true,
@@ -922,7 +924,7 @@ impl Region {
     }
 
     /// Returns the depth of `self` from the (1-based) binding level `depth`
-    pub fn from_depth(&self, depth: u32) -> Region {
+    pub fn from_depth(&self, depth: u32) -> RegionKind<'tcx> {
         match *self {
             ty::ReLateBound(debruijn, r) => ty::ReLateBound(DebruijnIndex {
                 depth: debruijn.depth - (depth - 1)
@@ -1334,7 +1336,7 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
     /// Returns the regions directly referenced from this type (but
     /// not types reachable from this type via `walk_tys`). This
     /// ignores late-bound regions binders.
-    pub fn regions(&self) -> Vec<&'tcx ty::Region> {
+    pub fn regions(&self) -> Vec<ty::Region<'tcx>> {
         match self.sty {
             TyRef(region, _) => {
                 vec![region]

src/librustc/ty/subst.rs

@@ -11,7 +11,7 @@
 // Type substitutions.
 
 use hir::def_id::DefId;
-use ty::{self, Slice, Ty, TyCtxt};
+use ty::{self, Slice, Region, Ty, TyCtxt};
 use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
 
 use serialize::{self, Encodable, Encoder, Decodable, Decoder};
@@ -32,7 +32,7 @@ use std::mem;
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Kind<'tcx> {
     ptr: NonZero<usize>,
-    marker: PhantomData<(Ty<'tcx>, &'tcx ty::Region)>
+    marker: PhantomData<(Ty<'tcx>, ty::Region<'tcx>)>
 }
 
 const TAG_MASK: usize = 0b11;
@@ -54,8 +54,8 @@ impl<'tcx> From<Ty<'tcx>> for Kind<'tcx> {
     }
 }
 
-impl<'tcx> From<&'tcx ty::Region> for Kind<'tcx> {
-    fn from(r: &'tcx ty::Region) -> Kind<'tcx> {
+impl<'tcx> From<ty::Region<'tcx>> for Kind<'tcx> {
+    fn from(r: ty::Region<'tcx>) -> Kind<'tcx> {
         // Ensure we can use the tag bits.
         assert_eq!(mem::align_of_val(r) & TAG_MASK, 0);
 
@@ -88,7 +88,7 @@ impl<'tcx> Kind<'tcx> {
     }
 
     #[inline]
-    pub fn as_region(self) -> Option<&'tcx ty::Region> {
+    pub fn as_region(self) -> Option<ty::Region<'tcx>> {
         unsafe {
             self.downcast(REGION_TAG)
         }
@@ -153,7 +153,7 @@ impl<'tcx> Decodable for Kind<'tcx> {
             d.read_enum_variant(&["Ty", "Region"], |d, tag| {
                 match tag {
                     TYPE_TAG => Ty::decode(d).map(Kind::from),
-                    REGION_TAG => <&ty::Region>::decode(d).map(Kind::from),
+                    REGION_TAG => Region::decode(d).map(Kind::from),
                     _ => Err(d.error("invalid Kind tag"))
                 }
             })
@@ -183,7 +183,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
                             mut mk_region: FR,
                             mut mk_type: FT)
                             -> &'tcx Substs<'tcx>
-    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> &'tcx ty::Region,
+    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> ty::Region<'tcx>,
           FT: FnMut(&ty::TypeParameterDef, &[Kind<'tcx>]) -> Ty<'tcx> {
         let defs = tcx.generics_of(def_id);
         let mut substs = Vec::with_capacity(defs.count());
@@ -197,7 +197,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
                              mut mk_region: FR,
                              mut mk_type: FT)
                              -> &'tcx Substs<'tcx>
-    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> &'tcx ty::Region,
+    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> ty::Region<'tcx>,
           FT: FnMut(&ty::TypeParameterDef, &[Kind<'tcx>]) -> Ty<'tcx>
     {
         let defs = tcx.generics_of(def_id);
@@ -212,7 +212,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
                          defs: &ty::Generics,
                          mk_region: &mut FR,
                          mk_type: &mut FT)
-    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> &'tcx ty::Region,
+    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> ty::Region<'tcx>,
           FT: FnMut(&ty::TypeParameterDef, &[Kind<'tcx>]) -> Ty<'tcx> {
 
         if let Some(def_id) = defs.parent {
@@ -226,7 +226,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
                            defs: &ty::Generics,
                            mk_region: &mut FR,
                            mk_type: &mut FT)
-    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> &'tcx ty::Region,
+    where FR: FnMut(&ty::RegionParameterDef, &[Kind<'tcx>]) -> ty::Region<'tcx>,
           FT: FnMut(&ty::TypeParameterDef, &[Kind<'tcx>]) -> Ty<'tcx> {
         // Handle Self first, before all regions.
         let mut types = defs.types.iter();
@@ -260,7 +260,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
     }
 
     #[inline]
-    pub fn regions(&'a self) -> impl DoubleEndedIterator<Item=&'tcx ty::Region> + 'a {
+    pub fn regions(&'a self) -> impl DoubleEndedIterator<Item=ty::Region<'tcx>> + 'a {
         self.iter().filter_map(|k| k.as_region())
     }
 
@@ -272,7 +272,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
     }
 
     #[inline]
-    pub fn region_at(&self, i: usize) -> &'tcx ty::Region {
+    pub fn region_at(&self, i: usize) -> ty::Region<'tcx> {
         self[i].as_region().unwrap_or_else(|| {
             bug!("expected region for param #{} in {:?}", i, self);
         })
@@ -284,7 +284,7 @@ impl<'a, 'gcx, 'tcx> Substs<'tcx> {
     }
 
     #[inline]
-    pub fn region_for_def(&self, def: &ty::RegionParameterDef) -> &'tcx ty::Region {
+    pub fn region_for_def(&self, def: &ty::RegionParameterDef) -> ty::Region<'tcx> {
         self.region_at(def.index as usize)
     }
 
@@ -396,7 +396,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for SubstFolder<'a, 'gcx, 'tcx> {
         t
     }
 
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         // Note: This routine only handles regions that are bound on
         // type declarations and other outer declarations, not those
         // bound in *fn types*. Region substitution of the bound
@@ -538,7 +538,7 @@ impl<'a, 'gcx, 'tcx> SubstFolder<'a, 'gcx, 'tcx> {
         result
     }
 
-    fn shift_region_through_binders(&self, region: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn shift_region_through_binders(&self, region: ty::Region<'tcx>) -> ty::Region<'tcx> {
         if self.region_binders_passed == 0 || !region.has_escaping_regions() {
             return region;
         }

src/librustc/ty/util.rs

@@ -316,7 +316,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn required_region_bounds(self,
                                   erased_self_ty: Ty<'tcx>,
                                   predicates: Vec<ty::Predicate<'tcx>>)
-                                  -> Vec<&'tcx ty::Region>    {
+                                  -> Vec<ty::Region<'tcx>>    {
         debug!("required_region_bounds(erased_self_ty={:?}, predicates={:?})",
                erased_self_ty,
                predicates);
@@ -457,7 +457,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
         let result = item_substs.iter().zip(impl_substs.iter())
             .filter(|&(_, &k)| {
-                if let Some(&ty::Region::ReEarlyBound(ref ebr)) = k.as_region() {
+                if let Some(&ty::RegionKind::ReEarlyBound(ref ebr)) = k.as_region() {
                     !impl_generics.region_param(ebr).pure_wrt_drop
                 } else if let Some(&ty::TyS {
                     sty: ty::TypeVariants::TyParam(ref pt), ..
@@ -673,7 +673,7 @@ impl<'a, 'gcx, 'tcx, W> TypeVisitor<'tcx> for TypeIdHasher<'a, 'gcx, 'tcx, W>
         ty.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         self.hash_discriminant_u8(r);
         match *r {
             ty::ReErased |

src/librustc/ty/wf.rs

@@ -116,9 +116,9 @@ pub fn predicate_obligations<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>,
 /// For `&'a T` to be WF, `T: 'a` must hold. So we can assume `T: 'a`.
 #[derive(Debug)]
 pub enum ImpliedBound<'tcx> {
-    RegionSubRegion(&'tcx ty::Region, &'tcx ty::Region),
-    RegionSubParam(&'tcx ty::Region, ty::ParamTy),
-    RegionSubProjection(&'tcx ty::Region, ty::ProjectionTy<'tcx>),
+    RegionSubRegion(ty::Region<'tcx>, ty::Region<'tcx>),
+    RegionSubParam(ty::Region<'tcx>, ty::ParamTy),
+    RegionSubProjection(ty::Region<'tcx>, ty::ProjectionTy<'tcx>),
 }
 
 /// Compute the implied bounds that a callee/impl can assume based on
@@ -198,7 +198,7 @@ pub fn implied_bounds<'a, 'gcx, 'tcx>(
 /// this down to determine what relationships would have to hold for
 /// `T: 'a` to hold. We get to assume that the caller has validated
 /// those relationships.
-fn implied_bounds_from_components<'tcx>(sub_region: &'tcx ty::Region,
+fn implied_bounds_from_components<'tcx>(sub_region: ty::Region<'tcx>,
                                         sup_components: Vec<Component<'tcx>>)
                                         -> Vec<ImpliedBound<'tcx>>
 {
@@ -455,7 +455,7 @@ impl<'a, 'gcx, 'tcx> WfPredicates<'a, 'gcx, 'tcx> {
 
     fn from_object_ty(&mut self, ty: Ty<'tcx>,
                       data: ty::Binder<&'tcx ty::Slice<ty::ExistentialPredicate<'tcx>>>,
-                      region: &'tcx ty::Region) {
+                      region: ty::Region<'tcx>) {
         // Imagine a type like this:
         //
         //     trait Foo { }
@@ -512,7 +512,7 @@ impl<'a, 'gcx, 'tcx> WfPredicates<'a, 'gcx, 'tcx> {
 pub fn object_region_bounds<'a, 'gcx, 'tcx>(
     tcx: TyCtxt<'a, 'gcx, 'tcx>,
     existential_predicates: ty::Binder<&'tcx ty::Slice<ty::ExistentialPredicate<'tcx>>>)
-    -> Vec<&'tcx ty::Region>
+    -> Vec<ty::Region<'tcx>>
 {
     // Since we don't actually *know* the self type for an object,
     // this "open(err)" serves as a kind of dummy standin -- basically

src/librustc/util/ppaux.rs

@@ -177,12 +177,12 @@ pub fn parameterized(f: &mut fmt::Formatter,
     let print_regions = |f: &mut fmt::Formatter, start: &str, skip, count| {
         // Don't print any regions if they're all erased.
         let regions = || substs.regions().skip(skip).take(count);
-        if regions().all(|r: &ty::Region| *r == ty::ReErased) {
+        if regions().all(|r: ty::Region| *r == ty::ReErased) {
             return Ok(());
         }
 
         for region in regions() {
-            let region: &ty::Region = region;
+            let region: ty::Region = region;
             start_or_continue(f, start, ", ")?;
             if verbose {
                 write!(f, "{:?}", region)?;
@@ -458,7 +458,7 @@ impl fmt::Debug for ty::BoundRegion {
     }
 }
 
-impl fmt::Debug for ty::Region {
+impl<'tcx> fmt::Debug for ty::RegionKind<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             ty::ReEarlyBound(ref data) => {
@@ -516,7 +516,7 @@ impl<'tcx> fmt::Debug for ty::ParameterEnvironment<'tcx> {
     }
 }
 
-impl fmt::Display for ty::Region {
+impl<'tcx> fmt::Display for ty::RegionKind<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if verbose() {
             return write!(f, "{:?}", *self);
@@ -544,7 +544,7 @@ impl fmt::Display for ty::Region {
     }
 }
 
-impl fmt::Debug for ty::FreeRegion {
+impl<'tcx> fmt::Debug for ty::FreeRegion<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "ReFree({:?}, {:?})",
                self.scope, self.bound_region)
@@ -689,14 +689,14 @@ impl<'tcx> fmt::Display for ty::Binder<ty::ProjectionPredicate<'tcx>> {
     }
 }
 
-impl<'tcx> fmt::Display for ty::Binder<ty::OutlivesPredicate<Ty<'tcx>, &'tcx ty::Region>> {
+impl<'tcx> fmt::Display for ty::Binder<ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         ty::tls::with(|tcx| in_binder(f, tcx, self, tcx.lift(self)))
     }
 }
 
-impl<'tcx> fmt::Display for ty::Binder<ty::OutlivesPredicate<&'tcx ty::Region,
-                                                             &'tcx ty::Region>> {
+impl<'tcx> fmt::Display for ty::Binder<ty::OutlivesPredicate<ty::Region<'tcx>,
+                                                             ty::Region<'tcx>>> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         ty::tls::with(|tcx| in_binder(f, tcx, self, tcx.lift(self)))
     }

src/librustc_borrowck/borrowck/check_loans.rs

@@ -126,7 +126,7 @@ impl<'a, 'tcx> euv::Delegate<'tcx> for CheckLoanCtxt<'a, 'tcx> {
               borrow_id: ast::NodeId,
               borrow_span: Span,
               cmt: mc::cmt<'tcx>,
-              loan_region: &'tcx ty::Region,
+              loan_region: ty::Region<'tcx>,
               bk: ty::BorrowKind,
               loan_cause: euv::LoanCause)
     {
@@ -232,14 +232,14 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
         })
     }
 
-    pub fn each_in_scope_loan<F>(&self, scope: region::CodeExtent, mut op: F) -> bool where
+    pub fn each_in_scope_loan<F>(&self, scope: region::CodeExtent<'tcx>, mut op: F) -> bool where
         F: FnMut(&Loan<'tcx>) -> bool,
     {
         //! Like `each_issued_loan()`, but only considers loans that are
         //! currently in scope.
 
         let tcx = self.tcx();
-        self.each_issued_loan(scope.node_id(&tcx.region_maps()), |loan| {
+        self.each_issued_loan(scope.node_id(), |loan| {
             if tcx.region_maps().is_subscope_of(scope, loan.kill_scope) {
                 op(loan)
             } else {
@@ -249,7 +249,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
     }
 
     fn each_in_scope_loan_affecting_path<F>(&self,
-                                            scope: region::CodeExtent,
+                                            scope: region::CodeExtent<'tcx>,
                                             loan_path: &LoanPath<'tcx>,
                                             mut op: F)
                                             -> bool where
@@ -460,8 +460,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
             // 3. Where does old loan expire.
 
             let previous_end_span =
-                self.tcx().hir.span(old_loan.kill_scope.node_id(&self.tcx().region_maps()))
-                              .end_point();
+                self.tcx().hir.span(old_loan.kill_scope.node_id()).end_point();
 
             let mut err = match (new_loan.kind, old_loan.kind) {
                 (ty::MutBorrow, ty::MutBorrow) => {
@@ -710,7 +709,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
         let mut ret = UseOk;
 
         self.each_in_scope_loan_affecting_path(
-            self.tcx().region_maps().node_extent(expr_id), use_path, |loan| {
+            self.tcx().node_extent(expr_id), use_path, |loan| {
             if !compatible_borrow_kinds(loan.kind, borrow_kind) {
                 ret = UseWhileBorrowed(loan.loan_path.clone(), loan.span);
                 false
@@ -824,7 +823,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
 
         // Check that we don't invalidate any outstanding loans
         if let Some(loan_path) = opt_loan_path(&assignee_cmt) {
-            let scope = self.tcx().region_maps().node_extent(assignment_id);
+            let scope = self.tcx().node_extent(assignment_id);
             self.each_in_scope_loan_affecting_path(scope, &loan_path, |loan| {
                 self.report_illegal_mutation(assignment_span, &loan_path, loan);
                 false

src/librustc_borrowck/borrowck/gather_loans/lifetime.rs

@@ -24,11 +24,11 @@ use syntax_pos::Span;
 type R = Result<(),()>;
 
 pub fn guarantee_lifetime<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
-                                    item_scope: region::CodeExtent,
+                                    item_scope: region::CodeExtent<'tcx>,
                                     span: Span,
                                     cause: euv::LoanCause,
                                     cmt: mc::cmt<'tcx>,
-                                    loan_region: &'tcx ty::Region,
+                                    loan_region: ty::Region<'tcx>,
                                     _: ty::BorrowKind)
                                     -> Result<(),()> {
     //! Reports error if `loan_region` is larger than S
@@ -52,11 +52,11 @@ struct GuaranteeLifetimeContext<'a, 'tcx: 'a> {
     bccx: &'a BorrowckCtxt<'a, 'tcx>,
 
     // the scope of the function body for the enclosing item
-    item_scope: region::CodeExtent,
+    item_scope: region::CodeExtent<'tcx>,
 
     span: Span,
     cause: euv::LoanCause,
-    loan_region: &'tcx ty::Region,
+    loan_region: ty::Region<'tcx>,
     cmt_original: mc::cmt<'tcx>
 }
 
@@ -92,7 +92,7 @@ impl<'a, 'tcx> GuaranteeLifetimeContext<'a, 'tcx> {
         }
     }
 
-    fn check_scope(&self, max_scope: &'tcx ty::Region) -> R {
+    fn check_scope(&self, max_scope: ty::Region<'tcx>) -> R {
         //! Reports an error if `loan_region` is larger than `max_scope`
 
         if !self.bccx.is_subregion_of(self.loan_region, max_scope) {
@@ -102,7 +102,7 @@ impl<'a, 'tcx> GuaranteeLifetimeContext<'a, 'tcx> {
         }
     }
 
-    fn scope(&self, cmt: &mc::cmt<'tcx>) -> &'tcx ty::Region {
+    fn scope(&self, cmt: &mc::cmt<'tcx>) -> ty::Region<'tcx> {
         //! Returns the maximal region scope for the which the
         //! lvalue `cmt` is guaranteed to be valid without any
         //! rooting etc, and presuming `cmt` is not mutated.

src/librustc_borrowck/borrowck/gather_loans/mod.rs

@@ -45,7 +45,7 @@ pub fn gather_loans_in_fn<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
         bccx: bccx,
         infcx: &infcx,
         all_loans: Vec::new(),
-        item_ub: bccx.tcx.region_maps().node_extent(body.node_id),
+        item_ub: bccx.tcx.node_extent(body.node_id),
         move_data: MoveData::new(),
         move_error_collector: move_error::MoveErrorCollector::new(),
     };
@@ -66,7 +66,7 @@ struct GatherLoanCtxt<'a, 'tcx: 'a> {
     all_loans: Vec<Loan<'tcx>>,
     /// `item_ub` is used as an upper-bound on the lifetime whenever we
     /// ask for the scope of an expression categorized as an upvar.
-    item_ub: region::CodeExtent,
+    item_ub: region::CodeExtent<'tcx>,
 }
 
 impl<'a, 'tcx> euv::Delegate<'tcx> for GatherLoanCtxt<'a, 'tcx> {
@@ -127,7 +127,7 @@ impl<'a, 'tcx> euv::Delegate<'tcx> for GatherLoanCtxt<'a, 'tcx> {
               borrow_id: ast::NodeId,
               borrow_span: Span,
               cmt: mc::cmt<'tcx>,
-              loan_region: &'tcx ty::Region,
+              loan_region: ty::Region<'tcx>,
               bk: ty::BorrowKind,
               loan_cause: euv::LoanCause)
     {
@@ -299,7 +299,7 @@ impl<'a, 'tcx> GatherLoanCtxt<'a, 'tcx> {
                        borrow_span: Span,
                        cmt: mc::cmt<'tcx>,
                        req_kind: ty::BorrowKind,
-                       loan_region: &'tcx ty::Region,
+                       loan_region: ty::Region<'tcx>,
                        cause: euv::LoanCause) {
         debug!("guarantee_valid(borrow_id={}, cmt={:?}, \
                 req_mutbl={:?}, loan_region={:?})",
@@ -371,7 +371,7 @@ impl<'a, 'tcx> GatherLoanCtxt<'a, 'tcx> {
                 };
                 debug!("loan_scope = {:?}", loan_scope);
 
-                let borrow_scope = self.tcx().region_maps().node_extent(borrow_id);
+                let borrow_scope = self.tcx().node_extent(borrow_id);
                 let gen_scope = self.compute_gen_scope(borrow_scope, loan_scope);
                 debug!("gen_scope = {:?}", gen_scope);
 
@@ -450,9 +450,9 @@ impl<'a, 'tcx> GatherLoanCtxt<'a, 'tcx> {
     }
 
     pub fn compute_gen_scope(&self,
-                             borrow_scope: region::CodeExtent,
-                             loan_scope: region::CodeExtent)
-                             -> region::CodeExtent {
+                             borrow_scope: region::CodeExtent<'tcx>,
+                             loan_scope: region::CodeExtent<'tcx>)
+                             -> region::CodeExtent<'tcx> {
         //! Determine when to introduce the loan. Typically the loan
         //! is introduced at the point of the borrow, but in some cases,
         //! notably method arguments, the loan may be introduced only
@@ -465,8 +465,8 @@ impl<'a, 'tcx> GatherLoanCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn compute_kill_scope(&self, loan_scope: region::CodeExtent, lp: &LoanPath<'tcx>)
-                              -> region::CodeExtent {
+    pub fn compute_kill_scope(&self, loan_scope: region::CodeExtent<'tcx>, lp: &LoanPath<'tcx>)
+                              -> region::CodeExtent<'tcx> {
         //! Determine when the loan restrictions go out of scope.
         //! This is either when the lifetime expires or when the
         //! local variable which roots the loan-path goes out of scope,

src/librustc_borrowck/borrowck/gather_loans/restrictions.rs

@@ -31,7 +31,7 @@ pub fn compute_restrictions<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
                                       span: Span,
                                       cause: euv::LoanCause,
                                       cmt: mc::cmt<'tcx>,
-                                      loan_region: &'tcx ty::Region)
+                                      loan_region: ty::Region<'tcx>)
                                       -> RestrictionResult<'tcx> {
     let ctxt = RestrictionsContext {
         bccx: bccx,
@@ -49,7 +49,7 @@ pub fn compute_restrictions<'a, 'tcx>(bccx: &BorrowckCtxt<'a, 'tcx>,
 struct RestrictionsContext<'a, 'tcx: 'a> {
     bccx: &'a BorrowckCtxt<'a, 'tcx>,
     span: Span,
-    loan_region: &'tcx ty::Region,
+    loan_region: ty::Region<'tcx>,
     cause: euv::LoanCause,
 }
 

src/librustc_borrowck/borrowck/mod.rs

@@ -141,9 +141,9 @@ fn build_borrowck_dataflow_data<'a, 'tcx>(this: &mut BorrowckCtxt<'a, 'tcx>,
                              id_range,
                              all_loans.len());
     for (loan_idx, loan) in all_loans.iter().enumerate() {
-        loan_dfcx.add_gen(loan.gen_scope.node_id(&tcx.region_maps()), loan_idx);
+        loan_dfcx.add_gen(loan.gen_scope.node_id(), loan_idx);
         loan_dfcx.add_kill(KillFrom::ScopeEnd,
-                           loan.kill_scope.node_id(&tcx.region_maps()), loan_idx);
+                           loan.kill_scope.node_id(), loan_idx);
     }
     loan_dfcx.add_kills_from_flow_exits(cfg);
     loan_dfcx.propagate(cfg, body);
@@ -206,13 +206,13 @@ pub struct Loan<'tcx> {
     /// cases, notably method arguments, the loan may be introduced
     /// only later, once it comes into scope.  See also
     /// `GatherLoanCtxt::compute_gen_scope`.
-    gen_scope: region::CodeExtent,
+    gen_scope: region::CodeExtent<'tcx>,
 
     /// kill_scope indicates when the loan goes out of scope.  This is
     /// either when the lifetime expires or when the local variable
     /// which roots the loan-path goes out of scope, whichever happens
     /// faster. See also `GatherLoanCtxt::compute_kill_scope`.
-    kill_scope: region::CodeExtent,
+    kill_scope: region::CodeExtent<'tcx>,
     span: Span,
     cause: euv::LoanCause,
 }
@@ -312,12 +312,12 @@ pub fn closure_to_block(closure_id: ast::NodeId,
 }
 
 impl<'a, 'tcx> LoanPath<'tcx> {
-    pub fn kill_scope(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> region::CodeExtent {
+    pub fn kill_scope(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> region::CodeExtent<'tcx> {
         match self.kind {
             LpVar(local_id) => tcx.region_maps().var_scope(local_id),
             LpUpvar(upvar_id) => {
                 let block_id = closure_to_block(upvar_id.closure_expr_id, tcx);
-                tcx.region_maps().node_extent(block_id)
+                tcx.node_extent(block_id)
             }
             LpDowncast(ref base, _) |
             LpExtend(ref base, ..) => base.kill_scope(tcx),
@@ -444,8 +444,8 @@ pub fn opt_loan_path<'tcx>(cmt: &mc::cmt<'tcx>) -> Option<Rc<LoanPath<'tcx>>> {
 pub enum bckerr_code<'tcx> {
     err_mutbl,
     /// superscope, subscope, loan cause
-    err_out_of_scope(&'tcx ty::Region, &'tcx ty::Region, euv::LoanCause),
-    err_borrowed_pointer_too_short(&'tcx ty::Region, &'tcx ty::Region), // loan, ptr
+    err_out_of_scope(ty::Region<'tcx>, ty::Region<'tcx>, euv::LoanCause),
+    err_borrowed_pointer_too_short(ty::Region<'tcx>, ty::Region<'tcx>), // loan, ptr
 }
 
 // Combination of an error code and the categorization of the expression
@@ -475,8 +475,8 @@ pub enum MovedValueUseKind {
 
 impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
     pub fn is_subregion_of(&self,
-                           r_sub: &'tcx ty::Region,
-                           r_sup: &'tcx ty::Region)
+                           r_sub: ty::Region<'tcx>,
+                           r_sup: ty::Region<'tcx>)
                            -> bool
     {
         self.tables.free_region_map.is_subregion_of(self.tcx, r_sub, r_sup)
@@ -963,10 +963,10 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
             .emit();
     }
 
-    fn region_end_span(&self, region: &'tcx ty::Region) -> Option<Span> {
+    fn region_end_span(&self, region: ty::Region<'tcx>) -> Option<Span> {
         match *region {
             ty::ReScope(scope) => {
-                match scope.span(&self.tcx.region_maps(), &self.tcx.hir) {
+                match scope.span(&self.tcx.hir) {
                     Some(s) => {
                         Some(s.end_point())
                     }
@@ -1244,10 +1244,10 @@ before rustc 1.16, this temporary lived longer - see issue #39283 \
     }
 }
 
-fn statement_scope_span(tcx: TyCtxt, region: &ty::Region) -> Option<Span> {
+fn statement_scope_span(tcx: TyCtxt, region: ty::Region) -> Option<Span> {
     match *region {
         ty::ReScope(scope) => {
-            match tcx.hir.find(scope.node_id(&tcx.region_maps())) {
+            match tcx.hir.find(scope.node_id()) {
                 Some(hir_map::NodeStmt(stmt)) => Some(stmt.span),
                 _ => None
             }

src/librustc_borrowck/borrowck/move_data.rs

@@ -548,7 +548,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
                 LpVar(..) | LpUpvar(..) | LpDowncast(..) => {
                     let kill_scope = path.loan_path.kill_scope(tcx);
                     let path = *self.path_map.borrow().get(&path.loan_path).unwrap();
-                    self.kill_moves(path, kill_scope.node_id(&tcx.region_maps()),
+                    self.kill_moves(path, kill_scope.node_id(),
                                     KillFrom::ScopeEnd, dfcx_moves);
                 }
                 LpExtend(..) => {}
@@ -563,7 +563,7 @@ impl<'a, 'tcx> MoveData<'tcx> {
                 LpVar(..) | LpUpvar(..) | LpDowncast(..) => {
                     let kill_scope = lp.kill_scope(tcx);
                     dfcx_assign.add_kill(KillFrom::ScopeEnd,
-                                         kill_scope.node_id(&tcx.region_maps()),
+                                         kill_scope.node_id(),
                                          assignment_index);
                 }
                 LpExtend(..) => {

src/librustc_const_eval/check_match.rs

@@ -533,7 +533,7 @@ impl<'a, 'gcx, 'tcx> Delegate<'tcx> for MutationChecker<'a, 'gcx> {
               _: ast::NodeId,
               span: Span,
               _: cmt,
-              _: &'tcx ty::Region,
+              _: ty::Region<'tcx>,
               kind:ty:: BorrowKind,
               _: LoanCause) {
         match kind {

src/librustc_const_eval/pattern.rs

@@ -35,7 +35,7 @@ pub enum PatternError<'tcx> {
 #[derive(Copy, Clone, Debug)]
 pub enum BindingMode<'tcx> {
     ByValue,
-    ByRef(&'tcx Region, BorrowKind),
+    ByRef(Region<'tcx>, BorrowKind),
 }
 
 #[derive(Clone, Debug)]
@@ -811,7 +811,7 @@ macro_rules! CloneImpls {
 }
 
 CloneImpls!{ <'tcx>
-    Span, Field, Mutability, ast::Name, ast::NodeId, usize, ConstVal<'tcx>, Region,
+    Span, Field, Mutability, ast::Name, ast::NodeId, usize, ConstVal<'tcx>, Region<'tcx>,
     Ty<'tcx>, BindingMode<'tcx>, &'tcx AdtDef,
     &'tcx Substs<'tcx>, &'tcx Kind<'tcx>
 }

src/librustc_data_structures/transitive_relation.rs

@@ -80,6 +80,27 @@ impl<T: Debug + PartialEq> TransitiveRelation<T> {
         }
     }
 
+    /// Applies the (partial) function to each edge and returns a new
+    /// relation.  If `f` returns `None` for any end-point, returns
+    /// `None`.
+    pub fn maybe_map<F, U>(&self, mut f: F) -> Option<TransitiveRelation<U>>
+        where F: FnMut(&T) -> Option<U>,
+              U: Debug + PartialEq,
+    {
+        let mut result = TransitiveRelation::new();
+        for edge in &self.edges {
+            let r = f(&self.elements[edge.source.0]).and_then(|source| {
+                f(&self.elements[edge.target.0]).and_then(|target| {
+                    Some(result.add(source, target))
+                })
+            });
+            if r.is_none() {
+                return None;
+            }
+        }
+        Some(result)
+    }
+
     /// Indicate that `a < b` (where `<` is this relation)
     pub fn add(&mut self, a: T, b: T) {
         let a = self.add_index(a);

src/librustc_driver/test.rs

@@ -293,7 +293,7 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
         self.infcx.tcx.mk_param(index, Symbol::intern(&name))
     }
 
-    pub fn re_early_bound(&self, index: u32, name: &'static str) -> &'tcx ty::Region {
+    pub fn re_early_bound(&self, index: u32, name: &'static str) -> ty::Region<'tcx> {
         let name = Symbol::intern(name);
         self.infcx.tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion {
             index: index,
@@ -304,11 +304,11 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
     pub fn re_late_bound_with_debruijn(&self,
                                        id: u32,
                                        debruijn: ty::DebruijnIndex)
-                                       -> &'tcx ty::Region {
+                                       -> ty::Region<'tcx> {
         self.infcx.tcx.mk_region(ty::ReLateBound(debruijn, ty::BrAnon(id)))
     }
 
-    pub fn t_rptr(&self, r: &'tcx ty::Region) -> Ty<'tcx> {
+    pub fn t_rptr(&self, r: ty::Region<'tcx>) -> Ty<'tcx> {
         self.infcx.tcx.mk_imm_ref(r, self.tcx().types.isize)
     }
 
@@ -330,7 +330,7 @@ impl<'a, 'gcx, 'tcx> Env<'a, 'gcx, 'tcx> {
         self.infcx.tcx.mk_imm_ref(self.infcx.tcx.mk_region(r), self.tcx().types.isize)
     }
 
-    pub fn re_free(&self, nid: ast::NodeId, id: u32) -> &'tcx ty::Region {
+    pub fn re_free(&self, nid: ast::NodeId, id: u32) -> ty::Region<'tcx> {
         self.infcx.tcx.mk_region(ty::ReFree(ty::FreeRegion {
             scope: self.tcx().region_maps.item_extent(nid),
             bound_region: ty::BrAnon(id),

src/librustc_metadata/decoder.rs

@@ -20,6 +20,7 @@ use rustc::middle::cstore::LinkagePreference;
 use rustc::hir::def::{self, Def, CtorKind};
 use rustc::hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc::middle::lang_items;
+use rustc::middle::region;
 use rustc::session::Session;
 use rustc::ty::{self, Ty, TyCtxt};
 use rustc::ty::subst::Substs;
@@ -352,12 +353,18 @@ impl<'a, 'tcx> SpecializedDecoder<&'tcx Substs<'tcx>> for DecodeContext<'a, 'tcx
     }
 }
 
-impl<'a, 'tcx> SpecializedDecoder<&'tcx ty::Region> for DecodeContext<'a, 'tcx> {
-    fn specialized_decode(&mut self) -> Result<&'tcx ty::Region, Self::Error> {
+impl<'a, 'tcx> SpecializedDecoder<ty::Region<'tcx>> for DecodeContext<'a, 'tcx> {
+    fn specialized_decode(&mut self) -> Result<ty::Region<'tcx>, Self::Error> {
         Ok(self.tcx().mk_region(Decodable::decode(self)?))
     }
 }
 
+impl<'a, 'tcx> SpecializedDecoder<region::CodeExtent<'tcx>> for DecodeContext<'a, 'tcx> {
+    fn specialized_decode(&mut self) -> Result<region::CodeExtent<'tcx>, Self::Error> {
+        Ok(self.tcx().intern_code_extent(Decodable::decode(self)?))
+    }
+}
+
 impl<'a, 'tcx> SpecializedDecoder<&'tcx ty::Slice<Ty<'tcx>>> for DecodeContext<'a, 'tcx> {
     fn specialized_decode(&mut self) -> Result<&'tcx ty::Slice<Ty<'tcx>>, Self::Error> {
         Ok(self.tcx().mk_type_list((0..self.read_usize()?).map(|_| Decodable::decode(self)))?)

src/librustc_mir/build/block.rs

@@ -83,7 +83,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     let_extent_stack.push(remainder_scope);
 
                     // Declare the bindings, which may create a visibility scope.
-                    let remainder_span = remainder_scope.span(&tcx.region_maps(), &tcx.hir);
+                    let remainder_span = remainder_scope.span(&tcx.hir);
                     let remainder_span = remainder_span.unwrap_or(span);
                     let scope = this.declare_bindings(None, remainder_span, &pattern);
 

src/librustc_mir/build/expr/as_operand.rs

@@ -39,7 +39,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// The operand is known to be live until the end of `scope`.
     pub fn as_operand<M>(&mut self,
                          block: BasicBlock,
-                         scope: Option<CodeExtent>,
+                         scope: Option<CodeExtent<'tcx>>,
                          expr: M) -> BlockAnd<Operand<'tcx>>
         where M: Mirror<'tcx, Output = Expr<'tcx>>
     {
@@ -49,7 +49,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     fn expr_as_operand(&mut self,
                        mut block: BasicBlock,
-                       scope: Option<CodeExtent>,
+                       scope: Option<CodeExtent<'tcx>>,
                        expr: Expr<'tcx>)
                        -> BlockAnd<Operand<'tcx>> {
         debug!("expr_as_operand(block={:?}, expr={:?})", block, expr);

src/librustc_mir/build/expr/as_rvalue.rs

@@ -38,7 +38,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     }
 
     /// Compile `expr`, yielding an rvalue.
-    pub fn as_rvalue<M>(&mut self, block: BasicBlock, scope: Option<CodeExtent>, expr: M)
+    pub fn as_rvalue<M>(&mut self, block: BasicBlock, scope: Option<CodeExtent<'tcx>>, expr: M)
                         -> BlockAnd<Rvalue<'tcx>>
         where M: Mirror<'tcx, Output = Expr<'tcx>>
     {
@@ -48,7 +48,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     fn expr_as_rvalue(&mut self,
                       mut block: BasicBlock,
-                      scope: Option<CodeExtent>,
+                      scope: Option<CodeExtent<'tcx>>,
                       expr: Expr<'tcx>)
                       -> BlockAnd<Rvalue<'tcx>> {
         debug!("expr_as_rvalue(block={:?}, expr={:?})", block, expr);

src/librustc_mir/build/expr/as_temp.rs

@@ -21,7 +21,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// up rvalues so as to freeze the value that will be consumed.
     pub fn as_temp<M>(&mut self,
                       block: BasicBlock,
-                      temp_lifetime: Option<CodeExtent>,
+                      temp_lifetime: Option<CodeExtent<'tcx>>,
                       expr: M)
                       -> BlockAnd<Lvalue<'tcx>>
         where M: Mirror<'tcx, Output = Expr<'tcx>>
@@ -32,7 +32,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     fn expr_as_temp(&mut self,
                     mut block: BasicBlock,
-                    temp_lifetime: Option<CodeExtent>,
+                    temp_lifetime: Option<CodeExtent<'tcx>>,
                     expr: Expr<'tcx>)
                     -> BlockAnd<Lvalue<'tcx>> {
         debug!("expr_as_temp(block={:?}, expr={:?})", block, expr);

src/librustc_mir/build/mod.rs

@@ -137,10 +137,10 @@ pub fn construct_fn<'a, 'gcx, 'tcx, A>(hir: Cx<'a, 'gcx, 'tcx>,
     let mut builder = Builder::new(hir, span, arguments.len(), return_ty);
 
     let call_site_extent =
-        tcx.region_maps().lookup_code_extent(
+        tcx.intern_code_extent(
             CodeExtentData::CallSiteScope { fn_id: fn_id, body_id: body.value.id });
     let arg_extent =
-        tcx.region_maps().lookup_code_extent(
+        tcx.intern_code_extent(
             CodeExtentData::ParameterScope { fn_id: fn_id, body_id: body.value.id });
     let mut block = START_BLOCK;
     unpack!(block = builder.in_scope(call_site_extent, block, |builder| {
@@ -205,8 +205,8 @@ pub fn construct_const<'a, 'gcx, 'tcx>(hir: Cx<'a, 'gcx, 'tcx>,
     let mut builder = Builder::new(hir, span, 0, ty);
 
     let region_maps = tcx.region_maps();
-    let extent = region_maps.temporary_scope(ast_expr.id)
-                            .unwrap_or(region_maps.item_extent(owner_id));
+    let extent = region_maps.temporary_scope(tcx, ast_expr.id)
+                            .unwrap_or(tcx.item_extent(owner_id));
     let mut block = START_BLOCK;
     let _ = builder.in_scope(extent, block, |builder| {
         let expr = builder.hir.mirror(ast_expr);
@@ -290,7 +290,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     fn args_and_body(&mut self,
                      mut block: BasicBlock,
                      arguments: &[(Ty<'gcx>, Option<&'gcx hir::Pat>)],
-                     argument_extent: CodeExtent,
+                     argument_extent: CodeExtent<'tcx>,
                      ast_body: &'gcx hir::Expr)
                      -> BlockAnd<()>
     {

src/librustc_mir/build/scope.rs

@@ -102,7 +102,7 @@ pub struct Scope<'tcx> {
     visibility_scope: VisibilityScope,
 
     /// the extent of this scope within source code.
-    extent: CodeExtent,
+    extent: CodeExtent<'tcx>,
 
     /// Whether there's anything to do for the cleanup path, that is,
     /// when unwinding through this scope. This includes destructors,
@@ -137,7 +137,7 @@ pub struct Scope<'tcx> {
     free: Option<FreeData<'tcx>>,
 
     /// The cache for drop chain on “normal” exit into a particular BasicBlock.
-    cached_exits: FxHashMap<(BasicBlock, CodeExtent), BasicBlock>,
+    cached_exits: FxHashMap<(BasicBlock, CodeExtent<'tcx>), BasicBlock>,
 }
 
 struct DropData<'tcx> {
@@ -180,7 +180,7 @@ struct FreeData<'tcx> {
 #[derive(Clone, Debug)]
 pub struct BreakableScope<'tcx> {
     /// Extent of the loop
-    pub extent: CodeExtent,
+    pub extent: CodeExtent<'tcx>,
     /// Where the body of the loop begins. `None` if block
     pub continue_block: Option<BasicBlock>,
     /// Block to branch into when the loop or block terminates (either by being `break`-en out
@@ -270,7 +270,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     /// Convenience wrapper that pushes a scope and then executes `f`
     /// to build its contents, popping the scope afterwards.
-    pub fn in_scope<F, R>(&mut self, extent: CodeExtent, mut block: BasicBlock, f: F) -> BlockAnd<R>
+    pub fn in_scope<F, R>(&mut self, extent: CodeExtent<'tcx>, mut block: BasicBlock, f: F) -> BlockAnd<R>
         where F: FnOnce(&mut Builder<'a, 'gcx, 'tcx>) -> BlockAnd<R>
     {
         debug!("in_scope(extent={:?}, block={:?})", extent, block);
@@ -285,7 +285,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// scope and call `pop_scope` afterwards. Note that these two
     /// calls must be paired; using `in_scope` as a convenience
     /// wrapper maybe preferable.
-    pub fn push_scope(&mut self, extent: CodeExtent) {
+    pub fn push_scope(&mut self, extent: CodeExtent<'tcx>) {
         debug!("push_scope({:?})", extent);
         let vis_scope = self.visibility_scope;
         self.scopes.push(Scope {
@@ -302,7 +302,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// drops onto the end of `block` that are needed.  This must
     /// match 1-to-1 with `push_scope`.
     pub fn pop_scope(&mut self,
-                     extent: CodeExtent,
+                     extent: CodeExtent<'tcx>,
                      mut block: BasicBlock)
                      -> BlockAnd<()> {
         debug!("pop_scope({:?}, {:?})", extent, block);
@@ -326,7 +326,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// module comment for details.
     pub fn exit_scope(&mut self,
                       span: Span,
-                      extent: CodeExtent,
+                      extent: CodeExtent<'tcx>,
                       mut block: BasicBlock,
                       target: BasicBlock) {
         debug!("exit_scope(extent={:?}, block={:?}, target={:?})", extent, block, target);
@@ -387,7 +387,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// resolving `break` and `continue`.
     pub fn find_breakable_scope(&mut self,
                            span: Span,
-                           label: CodeExtent)
+                           label: CodeExtent<'tcx>)
                            -> &mut BreakableScope<'tcx> {
         // find the loop-scope with the correct id
         self.breakable_scopes.iter_mut()
@@ -407,11 +407,11 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     /// Returns the extent of the scope which should be exited by a
     /// return.
-    pub fn extent_of_return_scope(&self) -> CodeExtent {
+    pub fn extent_of_return_scope(&self) -> CodeExtent<'tcx> {
         // The outermost scope (`scopes[0]`) will be the `CallSiteScope`.
         // We want `scopes[1]`, which is the `ParameterScope`.
         assert!(self.scopes.len() >= 2);
-        assert!(match self.hir.tcx().region_maps().code_extent_data(self.scopes[1].extent) {
+        assert!(match *self.scopes[1].extent {
             CodeExtentData::ParameterScope { .. } => true,
             _ => false,
         });
@@ -420,7 +420,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
     /// Returns the topmost active scope, which is known to be alive until
     /// the next scope expression.
-    pub fn topmost_scope(&self) -> CodeExtent {
+    pub fn topmost_scope(&self) -> CodeExtent<'tcx> {
         self.scopes.last().expect("topmost_scope: no scopes present").extent
     }
 
@@ -430,7 +430,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// `extent`.
     pub fn schedule_drop(&mut self,
                          span: Span,
-                         extent: CodeExtent,
+                         extent: CodeExtent<'tcx>,
                          lvalue: &Lvalue<'tcx>,
                          lvalue_ty: Ty<'tcx>) {
         let needs_drop = self.hir.needs_drop(lvalue_ty);
@@ -499,7 +499,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                     scope.needs_cleanup = true;
                 }
                 let tcx = self.hir.tcx();
-                let extent_span = extent.span(&tcx.region_maps(), &tcx.hir).unwrap();
+                let extent_span = extent.span(&tcx.hir).unwrap();
                 // Attribute scope exit drops to scope's closing brace
                 let scope_end = Span { lo: extent_span.hi, .. extent_span};
                 scope.drops.push(DropData {
@@ -520,7 +520,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// There may only be one “free” scheduled in any given scope.
     pub fn schedule_box_free(&mut self,
                              span: Span,
-                             extent: CodeExtent,
+                             extent: CodeExtent<'tcx>,
                              value: &Lvalue<'tcx>,
                              item_ty: Ty<'tcx>) {
         for scope in self.scopes.iter_mut().rev() {

src/librustc_mir/hair/cx/block.rs

@@ -24,7 +24,7 @@ impl<'tcx> Mirror<'tcx> for &'tcx hir::Block {
         let stmts = mirror_stmts(cx, self.id, &*self.stmts);
         Block {
             targeted_by_break: self.targeted_by_break,
-            extent: cx.tcx.region_maps().node_extent(self.id),
+            extent: cx.tcx.node_extent(self.id),
             span: self.span,
             stmts: stmts,
             expr: self.expr.to_ref(),
@@ -44,7 +44,7 @@ fn mirror_stmts<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                 result.push(StmtRef::Mirror(Box::new(Stmt {
                     span: stmt.span,
                     kind: StmtKind::Expr {
-                        scope: cx.tcx.region_maps().node_extent(id),
+                        scope: cx.tcx.node_extent(id),
                         expr: expr.to_ref(),
                     },
                 })))
@@ -60,14 +60,14 @@ fn mirror_stmts<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                             first_statement_index: index as u32,
                         });
                         let remainder_extent =
-                            cx.tcx.region_maps().lookup_code_extent(remainder_extent);
+                            cx.tcx.intern_code_extent(remainder_extent);
 
                         let pattern = Pattern::from_hir(cx.tcx, cx.tables(), &local.pat);
                         result.push(StmtRef::Mirror(Box::new(Stmt {
                             span: stmt.span,
                             kind: StmtKind::Let {
                                 remainder_scope: remainder_extent,
-                                init_scope: cx.tcx.region_maps().node_extent(id),
+                                init_scope: cx.tcx.node_extent(id),
                                 pattern: pattern,
                                 initializer: local.init.to_ref(),
                             },
@@ -84,7 +84,7 @@ pub fn to_expr_ref<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                    block: &'tcx hir::Block)
                                    -> ExprRef<'tcx> {
     let block_ty = cx.tables().node_id_to_type(block.id);
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(block.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, block.id);
     let expr = Expr {
         ty: block_ty,
         temp_lifetime: temp_lifetime,

src/librustc_mir/hair/cx/expr.rs

@@ -26,8 +26,8 @@ impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
     type Output = Expr<'tcx>;
 
     fn make_mirror<'a, 'gcx>(self, cx: &mut Cx<'a, 'gcx, 'tcx>) -> Expr<'tcx> {
-        let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(self.id);
-        let expr_extent = cx.tcx.region_maps().node_extent(self.id);
+        let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, self.id);
+        let expr_extent = cx.tcx.node_extent(self.id);
 
         debug!("Expr::make_mirror(): id={}, span={:?}", self.id, self.span);
 
@@ -216,7 +216,7 @@ impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
         };
 
         // Finally, create a destruction scope, if any.
-        if let Some(extent) = cx.tcx.region_maps().opt_destruction_extent(self.id) {
+        if let Some(extent) = cx.tcx.opt_destruction_extent(self.id) {
             expr = Expr {
                 temp_lifetime: temp_lifetime,
                 temp_lifetime_was_shrunk: was_shrunk,
@@ -238,7 +238,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                           expr: &'tcx hir::Expr)
                                           -> Expr<'tcx> {
     let expr_ty = cx.tables().expr_ty(expr);
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(expr.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, expr.id);
 
     let kind = match expr.node {
         // Here comes the interesting stuff:
@@ -610,7 +610,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
             match dest.target_id {
                 hir::ScopeTarget::Block(target_id) |
                 hir::ScopeTarget::Loop(hir::LoopIdResult::Ok(target_id)) => ExprKind::Break {
-                    label: cx.tcx.region_maps().node_extent(target_id),
+                    label: cx.tcx.node_extent(target_id),
                     value: value.to_ref(),
                 },
                 hir::ScopeTarget::Loop(hir::LoopIdResult::Err(err)) =>
@@ -621,7 +621,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
             match dest.target_id {
                 hir::ScopeTarget::Block(_) => bug!("cannot continue to blocks"),
                 hir::ScopeTarget::Loop(hir::LoopIdResult::Ok(loop_id)) => ExprKind::Continue {
-                    label: cx.tcx.region_maps().node_extent(loop_id),
+                    label: cx.tcx.node_extent(loop_id),
                 },
                 hir::ScopeTarget::Loop(hir::LoopIdResult::Err(err)) =>
                     bug!("invalid loop id for continue: {}", err)
@@ -686,7 +686,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         hir::ExprBox(ref value) => {
             ExprKind::Box {
                 value: value.to_ref(),
-                value_extents: cx.tcx.region_maps().node_extent(value.id),
+                value_extents: cx.tcx.node_extent(value.id),
             }
         }
         hir::ExprArray(ref fields) => ExprKind::Array { fields: fields.to_ref() },
@@ -707,7 +707,7 @@ fn method_callee<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                  method_call: ty::MethodCall)
                                  -> Expr<'tcx> {
     let callee = cx.tables().method_map[&method_call];
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(expr.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, expr.id);
     Expr {
         temp_lifetime: temp_lifetime,
         temp_lifetime_was_shrunk: was_shrunk,
@@ -791,7 +791,7 @@ fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                expr: &'tcx hir::Expr,
                                def: Def)
                                -> ExprKind<'tcx> {
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(expr.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, expr.id);
 
     match def {
         Def::Local(def_id) => {
@@ -827,8 +827,8 @@ fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
             // FIXME we're just hard-coding the idea that the
             // signature will be &self or &mut self and hence will
             // have a bound region with number 0
-            let region = ty::Region::ReFree(ty::FreeRegion {
-                scope: Some(cx.tcx.region_maps().node_extent(body_id)),
+            let region = ty::ReFree(ty::FreeRegion {
+                scope: Some(cx.tcx.node_extent(body_id)),
                 bound_region: ty::BoundRegion::BrAnon(0),
             });
             let region = cx.tcx.mk_region(region);
@@ -979,7 +979,7 @@ fn overloaded_operator<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         PassArgs::ByRef => {
             let region = cx.tcx.node_scope_region(expr.id);
             let (temp_lifetime, was_shrunk) =
-                cx.tcx.region_maps().temporary_scope2(expr.id);
+                cx.tcx.region_maps().temporary_scope2(cx.tcx, expr.id);
             argrefs.extend(args.iter()
                 .map(|arg| {
                     let arg_ty = cx.tables().expr_ty_adjusted(arg);
@@ -1031,7 +1031,7 @@ fn overloaded_lvalue<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
 
     // construct the complete expression `foo()` for the overloaded call,
     // which will yield the &T type
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(expr.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, expr.id);
     let ref_kind = overloaded_operator(cx, expr, method_call, pass_args, receiver, args);
     let ref_expr = Expr {
         temp_lifetime: temp_lifetime,
@@ -1056,7 +1056,7 @@ fn capture_freevar<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         closure_expr_id: closure_expr.id,
     };
     let upvar_capture = cx.tables().upvar_capture(upvar_id).unwrap();
-    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(closure_expr.id);
+    let (temp_lifetime, was_shrunk) = cx.tcx.region_maps().temporary_scope2(cx.tcx, closure_expr.id);
     let var_ty = cx.tables().node_id_to_type(id_var);
     let captured_var = Expr {
         temp_lifetime: temp_lifetime,

src/librustc_mir/hair/mod.rs

@@ -32,7 +32,7 @@ pub use rustc_const_eval::pattern::{BindingMode, Pattern, PatternKind, FieldPatt
 #[derive(Clone, Debug)]
 pub struct Block<'tcx> {
     pub targeted_by_break: bool,
-    pub extent: CodeExtent,
+    pub extent: CodeExtent<'tcx>,
     pub span: Span,
     pub stmts: Vec<StmtRef<'tcx>>,
     pub expr: Option<ExprRef<'tcx>>,
@@ -53,7 +53,7 @@ pub struct Stmt<'tcx> {
 pub enum StmtKind<'tcx> {
     Expr {
         /// scope for this statement; may be used as lifetime of temporaries
-        scope: CodeExtent,
+        scope: CodeExtent<'tcx>,
 
         /// expression being evaluated in this statement
         expr: ExprRef<'tcx>,
@@ -62,11 +62,11 @@ pub enum StmtKind<'tcx> {
     Let {
         /// scope for variables bound in this let; covers this and
         /// remaining statements in block
-        remainder_scope: CodeExtent,
+        remainder_scope: CodeExtent<'tcx>,
 
         /// scope for the initialization itself; might be used as
         /// lifetime of temporaries
-        init_scope: CodeExtent,
+        init_scope: CodeExtent<'tcx>,
 
         /// let <PAT> = ...
         pattern: Pattern<'tcx>,
@@ -97,7 +97,7 @@ pub struct Expr<'tcx> {
 
     /// lifetime of this expression if it should be spilled into a
     /// temporary; should be None only if in a constant context
-    pub temp_lifetime: Option<CodeExtent>,
+    pub temp_lifetime: Option<CodeExtent<'tcx>>,
 
     /// whether this temp lifetime was shrunk by #36082.
     pub temp_lifetime_was_shrunk: bool,
@@ -112,12 +112,12 @@ pub struct Expr<'tcx> {
 #[derive(Clone, Debug)]
 pub enum ExprKind<'tcx> {
     Scope {
-        extent: CodeExtent,
+        extent: CodeExtent<'tcx>,
         value: ExprRef<'tcx>,
     },
     Box {
         value: ExprRef<'tcx>,
-        value_extents: CodeExtent,
+        value_extents: CodeExtent<'tcx>,
     },
     Call {
         ty: ty::Ty<'tcx>,
@@ -205,16 +205,16 @@ pub enum ExprKind<'tcx> {
         id: DefId,
     },
     Borrow {
-        region: &'tcx Region,
+        region: Region<'tcx>,
         borrow_kind: BorrowKind,
         arg: ExprRef<'tcx>,
     },
     Break {
-        label: CodeExtent,
+        label: CodeExtent<'tcx>,
         value: Option<ExprRef<'tcx>>,
     },
     Continue {
-        label: CodeExtent,
+        label: CodeExtent<'tcx>,
     },
     Return {
         value: Option<ExprRef<'tcx>>,

src/librustc_mir/mir_map.rs

@@ -252,8 +252,8 @@ fn closure_self_ty<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              -> Ty<'tcx> {
     let closure_ty = tcx.body_tables(body_id).node_id_to_type(closure_expr_id);
 
-    let region = ty::Region::ReFree(ty::FreeRegion {
-        scope: Some(tcx.region_maps().item_extent(body_id.node_id)),
+    let region = ty::ReFree(ty::FreeRegion {
+        scope: Some(tcx.item_extent(body_id.node_id)),
         bound_region: ty::BoundRegion::BrEnv,
     });
     let region = tcx.mk_region(region);

src/librustc_passes/consts.rs

@@ -480,7 +480,7 @@ impl<'a, 'gcx, 'tcx> euv::Delegate<'tcx> for CheckCrateVisitor<'a, 'gcx> {
               borrow_id: ast::NodeId,
               _borrow_span: Span,
               cmt: mc::cmt<'tcx>,
-              _loan_region: &'tcx ty::Region,
+              _loan_region: ty::Region<'tcx>,
               bk: ty::BorrowKind,
               loan_cause: euv::LoanCause) {
         // Kind of hacky, but we allow Unsafe coercions in constants.

src/librustc_typeck/astconv.rs

@@ -53,7 +53,7 @@ pub trait AstConv<'gcx, 'tcx> {
 
     /// What lifetime should we use when a lifetime is omitted (and not elided)?
     fn re_infer(&self, span: Span, _def: Option<&ty::RegionParameterDef>)
-                -> Option<&'tcx ty::Region>;
+                -> Option<ty::Region<'tcx>>;
 
     /// What type should we use when a type is omitted?
     fn ty_infer(&self, span: Span) -> Ty<'tcx>;
@@ -104,7 +104,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
     pub fn ast_region_to_region(&self,
         lifetime: &hir::Lifetime,
         def: Option<&ty::RegionParameterDef>)
-        -> &'tcx ty::Region
+        -> ty::Region<'tcx>
     {
         let tcx = self.tcx();
         let r = match tcx.named_region_map.defs.get(&lifetime.id) {
@@ -133,7 +133,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
             Some(&rl::Region::Free(scope, id)) => {
                 let name = tcx.hir.name(id);
                 tcx.mk_region(ty::ReFree(ty::FreeRegion {
-                    scope: Some(scope.to_code_extent(&tcx.region_maps())),
+                    scope: Some(scope.to_code_extent(tcx)),
                     bound_region: ty::BrNamed(tcx.hir.local_def_id(id), name)
                 }))
 
@@ -1342,7 +1342,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
     fn compute_object_lifetime_bound(&self,
         span: Span,
         existential_predicates: ty::Binder<&'tcx ty::Slice<ty::ExistentialPredicate<'tcx>>>)
-        -> Option<&'tcx ty::Region> // if None, use the default
+        -> Option<ty::Region<'tcx>> // if None, use the default
     {
         let tcx = self.tcx();
 
@@ -1489,7 +1489,7 @@ fn report_lifetime_number_error(tcx: TyCtxt, span: Span, number: usize, expected
 // and return from functions in multiple places.
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub struct Bounds<'tcx> {
-    pub region_bounds: Vec<&'tcx ty::Region>,
+    pub region_bounds: Vec<ty::Region<'tcx>>,
     pub implicitly_sized: bool,
     pub trait_bounds: Vec<ty::PolyTraitRef<'tcx>>,
     pub projection_bounds: Vec<ty::PolyProjectionPredicate<'tcx>>,
@@ -1533,7 +1533,7 @@ impl<'a, 'gcx, 'tcx> Bounds<'tcx> {
 
 pub enum ExplicitSelf<'tcx> {
     ByValue,
-    ByReference(&'tcx ty::Region, hir::Mutability),
+    ByReference(ty::Region<'tcx>, hir::Mutability),
     ByBox
 }
 

src/librustc_typeck/check/closure.rs

@@ -73,7 +73,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
         debug!("check_closure: expr.id={:?} closure_type={:?}", expr.id, closure_type);
 
-        let extent = self.tcx.region_maps().call_site_extent(expr.id, body.value.id);
+        let extent = self.tcx.call_site_extent(expr.id, body.value.id);
         let fn_sig = self.tcx.liberate_late_bound_regions(Some(extent), &sig);
         let fn_sig = self.inh.normalize_associated_types_in(body.value.span,
                                                             body.value.id, &fn_sig);

src/librustc_typeck/check/coercion.rs

@@ -250,7 +250,7 @@ impl<'f, 'gcx, 'tcx> Coerce<'f, 'gcx, 'tcx> {
                                   exprs: &[E],
                                   a: Ty<'tcx>,
                                   b: Ty<'tcx>,
-                                  r_b: &'tcx ty::Region,
+                                  r_b: ty::Region<'tcx>,
                                   mt_b: TypeAndMut<'tcx>)
                                   -> CoerceResult<'tcx>
         where E: AsCoercionSite

src/librustc_typeck/check/dropck.rs

@@ -271,7 +271,7 @@ pub fn check_safety_of_destructor_if_necessary<'a, 'gcx, 'tcx>(
     rcx: &mut RegionCtxt<'a, 'gcx, 'tcx>,
     ty: ty::Ty<'tcx>,
     span: Span,
-    scope: region::CodeExtent)
+    scope: region::CodeExtent<'tcx>)
     -> Result<(), ErrorReported>
 {
     debug!("check_safety_of_destructor_if_necessary typ: {:?} scope: {:?}",

src/librustc_typeck/check/mod.rs

@@ -781,7 +781,7 @@ fn typeck_tables_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             check_abi(tcx, span, fn_sig.abi());
 
             // Compute the fty from point of view of inside fn.
-            let fn_scope = inh.tcx.region_maps().call_site_extent(id, body_id.node_id);
+            let fn_scope = inh.tcx.call_site_extent(id, body_id.node_id);
             let fn_sig =
                 fn_sig.subst(inh.tcx, &inh.parameter_environment.free_substs);
             let fn_sig =
@@ -1549,7 +1549,7 @@ impl<'a, 'gcx, 'tcx> AstConv<'gcx, 'tcx> for FnCtxt<'a, 'gcx, 'tcx> {
     }
 
     fn re_infer(&self, span: Span, def: Option<&ty::RegionParameterDef>)
-                -> Option<&'tcx ty::Region> {
+                -> Option<ty::Region<'tcx>> {
         let v = match def {
             Some(def) => infer::EarlyBoundRegion(span, def.name, def.issue_32330),
             None => infer::MiscVariable(span)
@@ -1963,7 +1963,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
     /// outlive the region `r`.
     pub fn register_region_obligation(&self,
                                       ty: Ty<'tcx>,
-                                      region: &'tcx ty::Region,
+                                      region: ty::Region<'tcx>,
                                       cause: traits::ObligationCause<'tcx>)
     {
         let mut fulfillment_cx = self.fulfillment_cx.borrow_mut();

src/librustc_typeck/check/regionck.rs

@@ -171,15 +171,15 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 pub struct RegionCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     pub fcx: &'a FnCtxt<'a, 'gcx, 'tcx>,
 
-    region_bound_pairs: Vec<(&'tcx ty::Region, GenericKind<'tcx>)>,
+    region_bound_pairs: Vec<(ty::Region<'tcx>, GenericKind<'tcx>)>,
 
-    free_region_map: FreeRegionMap,
+    free_region_map: FreeRegionMap<'tcx>,
 
     // id of innermost fn body id
     body_id: ast::NodeId,
 
     // call_site scope of innermost fn
-    call_site_scope: Option<CodeExtent>,
+    call_site_scope: Option<CodeExtent<'tcx>>,
 
     // id of innermost fn or loop
     repeating_scope: ast::NodeId,
@@ -215,7 +215,8 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
-    fn set_call_site_scope(&mut self, call_site_scope: Option<CodeExtent>) -> Option<CodeExtent> {
+    fn set_call_site_scope(&mut self, call_site_scope: Option<CodeExtent<'tcx>>)
+                           -> Option<CodeExtent<'tcx>> {
         mem::replace(&mut self.call_site_scope, call_site_scope)
     }
 
@@ -276,7 +277,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
         let body_id = body.id();
 
-        let call_site = self.tcx.region_maps().lookup_code_extent(
+        let call_site = self.tcx.intern_code_extent(
             region::CodeExtentData::CallSiteScope { fn_id: id, body_id: body_id.node_id });
         let old_call_site_scope = self.set_call_site_scope(Some(call_site));
 
@@ -302,7 +303,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
         let old_body_id = self.set_body_id(body_id.node_id);
         self.relate_free_regions(&fn_sig_tys[..], body_id.node_id, span);
-        self.link_fn_args(self.tcx.region_maps().node_extent(body_id.node_id), &body.arguments);
+        self.link_fn_args(self.tcx.node_extent(body_id.node_id), &body.arguments);
         self.visit_body(body);
         self.visit_region_obligations(body_id.node_id);
 
@@ -868,7 +869,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
         // call occurs.
         //
         // FIXME(#6268) to support nested method calls, should be callee_id
-        let callee_scope = self.tcx.region_maps().node_extent(call_expr.id);
+        let callee_scope = self.tcx.node_extent(call_expr.id);
         let callee_region = self.tcx.mk_region(ty::ReScope(callee_scope));
 
         debug!("callee_region={:?}", callee_region);
@@ -982,8 +983,8 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
     pub fn mk_subregion_due_to_dereference(&mut self,
                                            deref_span: Span,
-                                           minimum_lifetime: &'tcx ty::Region,
-                                           maximum_lifetime: &'tcx ty::Region) {
+                                           minimum_lifetime: ty::Region<'tcx>,
+                                           maximum_lifetime: ty::Region<'tcx>) {
         self.sub_regions(infer::DerefPointer(deref_span),
                          minimum_lifetime, maximum_lifetime)
     }
@@ -1021,7 +1022,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
         debug!("constrain_index(index_expr=?, indexed_ty={}",
                self.ty_to_string(indexed_ty));
 
-        let r_index_expr = ty::ReScope(self.tcx.region_maps().node_extent(index_expr.id));
+        let r_index_expr = ty::ReScope(self.tcx.node_extent(index_expr.id));
         if let ty::TyRef(r_ptr, mt) = indexed_ty.sty {
             match mt.ty.sty {
                 ty::TySlice(_) | ty::TyStr => {
@@ -1038,7 +1039,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     fn type_of_node_must_outlive(&mut self,
         origin: infer::SubregionOrigin<'tcx>,
         id: ast::NodeId,
-        minimum_lifetime: &'tcx ty::Region)
+        minimum_lifetime: ty::Region<'tcx>)
     {
         // Try to resolve the type.  If we encounter an error, then typeck
         // is going to fail anyway, so just stop here and let typeck
@@ -1101,7 +1102,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     /// Computes the guarantors for any ref bindings in a match and
     /// then ensures that the lifetime of the resulting pointer is
     /// linked to the lifetime of its guarantor (if any).
-    fn link_fn_args(&self, body_scope: CodeExtent, args: &[hir::Arg]) {
+    fn link_fn_args(&self, body_scope: CodeExtent<'tcx>, args: &[hir::Arg]) {
         debug!("regionck::link_fn_args(body_scope={:?})", body_scope);
         let mc = mc::MemCategorizationContext::new(self);
         for arg in args {
@@ -1167,7 +1168,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     /// must outlive `callee_scope`.
     fn link_by_ref(&self,
                    expr: &hir::Expr,
-                   callee_scope: CodeExtent) {
+                   callee_scope: CodeExtent<'tcx>) {
         debug!("link_by_ref(expr={:?}, callee_scope={:?})",
                expr, callee_scope);
         let mc = mc::MemCategorizationContext::new(self);
@@ -1200,7 +1201,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     /// between regions, as explained in `link_reborrowed_region()`.
     fn link_region(&self,
                    span: Span,
-                   borrow_region: &'tcx ty::Region,
+                   borrow_region: ty::Region<'tcx>,
                    borrow_kind: ty::BorrowKind,
                    borrow_cmt: mc::cmt<'tcx>) {
         let mut borrow_cmt = borrow_cmt;
@@ -1297,10 +1298,10 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     /// recurse and process `ref_cmt` (see case 2 above).
     fn link_reborrowed_region(&self,
                               span: Span,
-                              borrow_region: &'tcx ty::Region,
+                              borrow_region: ty::Region<'tcx>,
                               borrow_kind: ty::BorrowKind,
                               ref_cmt: mc::cmt<'tcx>,
-                              ref_region: &'tcx ty::Region,
+                              ref_region: ty::Region<'tcx>,
                               mut ref_kind: ty::BorrowKind,
                               note: mc::Note)
                               -> Option<(mc::cmt<'tcx>, ty::BorrowKind)>
@@ -1411,7 +1412,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
                           origin: infer::ParameterOrigin,
                           substs: &Substs<'tcx>,
                           expr_span: Span,
-                          expr_region: &'tcx ty::Region) {
+                          expr_region: ty::Region<'tcx>) {
         debug!("substs_wf_in_scope(substs={:?}, \
                 expr_region={:?}, \
                 origin={:?}, \
@@ -1436,7 +1437,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     pub fn type_must_outlive(&self,
                              origin: infer::SubregionOrigin<'tcx>,
                              ty: Ty<'tcx>,
-                             region: &'tcx ty::Region)
+                             region: ty::Region<'tcx>)
     {
         let ty = self.resolve_type(ty);
 
@@ -1454,7 +1455,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     fn components_must_outlive(&self,
                                origin: infer::SubregionOrigin<'tcx>,
                                components: Vec<ty::outlives::Component<'tcx>>,
-                               region: &'tcx ty::Region)
+                               region: ty::Region<'tcx>)
     {
         for component in components {
             let origin = origin.clone();
@@ -1485,7 +1486,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
     fn param_ty_must_outlive(&self,
                              origin: infer::SubregionOrigin<'tcx>,
-                             region: &'tcx ty::Region,
+                             region: ty::Region<'tcx>,
                              param_ty: ty::ParamTy) {
         debug!("param_ty_must_outlive(region={:?}, param_ty={:?}, origin={:?})",
                region, param_ty, origin);
@@ -1497,7 +1498,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
     fn projection_must_outlive(&self,
                                origin: infer::SubregionOrigin<'tcx>,
-                               region: &'tcx ty::Region,
+                               region: ty::Region<'tcx>,
                                projection_ty: ty::ProjectionTy<'tcx>)
     {
         debug!("projection_must_outlive(region={:?}, projection_ty={:?}, origin={:?})",
@@ -1622,7 +1623,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     fn projection_declared_bounds(&self,
                                   span: Span,
                                   projection_ty: ty::ProjectionTy<'tcx>)
-                                  -> Vec<&'tcx ty::Region>
+                                  -> Vec<ty::Region<'tcx>>
     {
         // First assemble bounds from where clauses and traits.
 
@@ -1637,7 +1638,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
 
     fn projection_bound(&self,
                         span: Span,
-                        declared_bounds: Vec<&'tcx ty::Region>,
+                        declared_bounds: Vec<ty::Region<'tcx>>,
                         projection_ty: ty::ProjectionTy<'tcx>)
                         -> VerifyBound<'tcx> {
         debug!("projection_bound(declared_bounds={:?}, projection_ty={:?})",
@@ -1673,7 +1674,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     }
 
     fn declared_generic_bounds_from_env(&self, generic: GenericKind<'tcx>)
-                                        -> Vec<&'tcx ty::Region>
+                                        -> Vec<ty::Region<'tcx>>
     {
         let param_env = &self.parameter_environment;
 
@@ -1707,7 +1708,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
     fn declared_projection_bounds_from_trait(&self,
                                              span: Span,
                                              projection_ty: ty::ProjectionTy<'tcx>)
-                                             -> Vec<&'tcx ty::Region>
+                                             -> Vec<ty::Region<'tcx>>
     {
         debug!("projection_bounds(projection_ty={:?})",
                projection_ty);

src/librustc_typeck/check/upvar.rs

@@ -536,7 +536,7 @@ impl<'a, 'gcx, 'tcx> euv::Delegate<'tcx> for AdjustBorrowKind<'a, 'gcx, 'tcx> {
               borrow_id: ast::NodeId,
               _borrow_span: Span,
               cmt: mc::cmt<'tcx>,
-              _loan_region: &'tcx ty::Region,
+              _loan_region: ty::Region<'tcx>,
               bk: ty::BorrowKind,
               _loan_cause: euv::LoanCause)
     {

src/librustc_typeck/check/wfcheck.rs

@@ -341,7 +341,7 @@ impl<'a, 'gcx> CheckTypeWellFormedVisitor<'a, 'gcx> {
             let predicates = fcx.instantiate_bounds(item.span, def_id, free_substs);
 
             let mut implied_bounds = vec![];
-            let free_id_outlive = fcx.tcx.region_maps().call_site_extent(item.id, body_id.node_id);
+            let free_id_outlive = fcx.tcx.call_site_extent(item.id, body_id.node_id);
             this.check_fn_or_method(fcx, item.span, sig, &predicates,
                                     Some(free_id_outlive), &mut implied_bounds);
             implied_bounds
@@ -429,7 +429,7 @@ impl<'a, 'gcx> CheckTypeWellFormedVisitor<'a, 'gcx> {
                                       span: Span,
                                       sig: ty::PolyFnSig<'tcx>,
                                       predicates: &ty::InstantiatedPredicates<'tcx>,
-                                      free_id_outlive: Option<CodeExtent>,
+                                      free_id_outlive: Option<CodeExtent<'tcx>>,
                                       implied_bounds: &mut Vec<Ty<'tcx>>)
     {
         let free_substs = &fcx.parameter_environment.free_substs;
@@ -453,7 +453,7 @@ impl<'a, 'gcx> CheckTypeWellFormedVisitor<'a, 'gcx> {
                                          fcx: &FnCtxt<'fcx, 'gcx, 'tcx>,
                                          method_sig: &hir::MethodSig,
                                          method: &ty::AssociatedItem,
-                                         free_id_outlive: Option<CodeExtent>,
+                                         free_id_outlive: Option<CodeExtent<'tcx>>,
                                          self_ty: ty::Ty<'tcx>)
     {
         // check that the type of the method's receiver matches the

src/librustc_typeck/check/writeback.rs

@@ -76,7 +76,7 @@ struct WritebackCx<'cx, 'gcx: 'cx+'tcx, 'tcx: 'cx> {
     // early-bound versions of them, visible from the
     // outside of the function. This is needed by, and
     // only populated if there are any `impl Trait`.
-    free_to_bound_regions: DefIdMap<&'gcx ty::Region>,
+    free_to_bound_regions: DefIdMap<ty::Region<'gcx>>,
 
     body: &'gcx hir::Body,
 }
@@ -275,7 +275,9 @@ impl<'cx, 'gcx, 'tcx> WritebackCx<'cx, 'gcx, 'tcx> {
     }
 
     fn visit_free_region_map(&mut self) {
-        self.tables.free_region_map = self.fcx.tables.borrow().free_region_map.clone();
+        let free_region_map = self.tcx().lift_to_global(&self.fcx.tables.borrow().free_region_map);
+        let free_region_map = free_region_map.expect("all regions in free-region-map are global");
+        self.tables.free_region_map = free_region_map;
     }
 
     fn visit_anon_types(&mut self) {
@@ -522,7 +524,7 @@ impl<'cx, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for Resolver<'cx, 'gcx, 'tcx> {
 
     // FIXME This should be carefully checked
     // We could use `self.report_error` but it doesn't accept a ty::Region, right now.
-    fn fold_region(&mut self, r: &'tcx ty::Region) -> &'tcx ty::Region {
+    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
         match self.infcx.fully_resolve(&r) {
             Ok(r) => r,
             Err(_) => {

src/librustc_typeck/collect.rs

@@ -215,7 +215,7 @@ impl<'a, 'tcx> AstConv<'tcx, 'tcx> for ItemCtxt<'a, 'tcx> {
     }
 
     fn re_infer(&self, _span: Span, _def: Option<&ty::RegionParameterDef>)
-                -> Option<&'tcx ty::Region> {
+                -> Option<ty::Region<'tcx>> {
         None
     }
 

src/librustc_typeck/constrained_type_params.rs

@@ -75,7 +75,7 @@ impl<'tcx> TypeVisitor<'tcx> for ParameterCollector {
         t.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: &'tcx ty::Region) -> bool {
+    fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
         match *r {
             ty::ReEarlyBound(data) => {
                 self.parameters.push(Parameter::from(data));

src/librustc_typeck/variance/constraints.rs

@@ -479,7 +479,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
     /// context with ambient variance `variance`
     fn add_constraints_from_region(&mut self,
                                    generics: &ty::Generics,
-                                   region: &'tcx ty::Region,
+                                   region: ty::Region<'tcx>,
                                    variance: VarianceTermPtr<'a>) {
         match *region {
             ty::ReEarlyBound(ref data) => {

src/librustdoc/clean/mod.rs

@@ -726,7 +726,7 @@ impl<'tcx> Clean<TyParamBound> for ty::TraitRef<'tcx> {
             if let ty::TyTuple(ts, _) = ty_s.sty {
                 for &ty_s in ts {
                     if let ty::TyRef(ref reg, _) = ty_s.sty {
-                        if let &ty::Region::ReLateBound(..) = *reg {
+                        if let &ty::RegionKind::ReLateBound(..) = *reg {
                             debug!("  hit an ReLateBound {:?}", reg);
                             if let Some(lt) = reg.clean(cx) {
                                 late_bounds.push(lt);
@@ -819,7 +819,7 @@ impl Clean<Lifetime> for ty::RegionParameterDef {
     }
 }
 
-impl Clean<Option<Lifetime>> for ty::Region {
+impl<'tcx> Clean<Option<Lifetime>> for ty::RegionKind<'tcx> {
     fn clean(&self, cx: &DocContext) -> Option<Lifetime> {
         match *self {
             ty::ReStatic => Some(Lifetime::statik()),
@@ -915,7 +915,7 @@ impl<'tcx> Clean<WherePredicate> for ty::SubtypePredicate<'tcx> {
     }
 }
 
-impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<&'tcx ty::Region, &'tcx ty::Region> {
+impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>> {
     fn clean(&self, cx: &DocContext) -> WherePredicate {
         let ty::OutlivesPredicate(ref a, ref b) = *self;
         WherePredicate::RegionPredicate {
@@ -925,7 +925,7 @@ impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<&'tcx ty::Region, &'t
     }
 }
 
-impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<ty::Ty<'tcx>, &'tcx ty::Region> {
+impl<'tcx> Clean<WherePredicate> for ty::OutlivesPredicate<ty::Ty<'tcx>, ty::Region<'tcx>> {
     fn clean(&self, cx: &DocContext) -> WherePredicate {
         let ty::OutlivesPredicate(ref ty, ref lt) = *self;
 

src/test/run-pass/kindck-implicit-close-over-mut-var.rs

@@ -1,4 +1,4 @@
-// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+s// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //