diff --git a/src/librustc/ich/caching_codemap_view.rs b/src/librustc/ich/caching_codemap_view.rs
index 9aecd8ad836..bf47b9bb9d4 100644
--- a/src/librustc/ich/caching_codemap_view.rs
+++ b/src/librustc/ich/caching_codemap_view.rs
@@ -29,8 +29,8 @@ pub struct CachingCodemapView<'tcx> {
     time_stamp: usize,
 }
 
-impl<'tcx> CachingCodemapView<'tcx> {
-    pub fn new<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> CachingCodemapView<'tcx> {
+impl<'gcx> CachingCodemapView<'gcx> {
+    pub fn new<'a, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>) -> CachingCodemapView<'gcx> {
         let codemap = tcx.sess.codemap();
         let files = codemap.files();
         let first_file = files[0].clone();
diff --git a/src/librustc/ich/hcx.rs b/src/librustc/ich/hcx.rs
index a8355488941..2784a7bd024 100644
--- a/src/librustc/ich/hcx.rs
+++ b/src/librustc/ich/hcx.rs
@@ -33,9 +33,9 @@ use rustc_data_structures::accumulate_vec::AccumulateVec;
 /// enough information to transform DefIds and HirIds into stable DefPaths (i.e.
 /// a reference to the TyCtxt) and it holds a few caches for speeding up various
 /// things (e.g. each DefId/DefPath is only hashed once).
-pub struct StableHashingContext<'a, 'tcx: 'a> {
-    tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
-    codemap: CachingCodemapView<'tcx>,
+pub struct StableHashingContext<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
+    tcx: ty::TyCtxt<'a, 'gcx, 'tcx>,
+    codemap: CachingCodemapView<'gcx>,
     hash_spans: bool,
     hash_bodies: bool,
     overflow_checks_enabled: bool,
@@ -51,9 +51,9 @@ pub enum NodeIdHashingMode {
     HashTraitsInScope,
 }
 
-impl<'a, 'tcx: 'a> StableHashingContext<'a, 'tcx> {
+impl<'a, 'gcx, 'tcx> StableHashingContext<'a, 'gcx, 'tcx> {
 
-    pub fn new(tcx: ty::TyCtxt<'a, 'tcx, 'tcx>) -> Self {
+    pub fn new(tcx: ty::TyCtxt<'a, 'gcx, 'tcx>) -> Self {
         let hash_spans_initial = tcx.sess.opts.debuginfo != NoDebugInfo;
         let check_overflow_initial = tcx.sess.overflow_checks();
 
@@ -111,7 +111,7 @@ impl<'a, 'tcx: 'a> StableHashingContext<'a, 'tcx> {
     }
 
     #[inline]
-    pub fn tcx(&self) -> ty::TyCtxt<'a, 'tcx, 'tcx> {
+    pub fn tcx(&self) -> ty::TyCtxt<'a, 'gcx, 'tcx> {
         self.tcx
     }
 
@@ -131,7 +131,7 @@ impl<'a, 'tcx: 'a> StableHashingContext<'a, 'tcx> {
     }
 
     #[inline]
-    pub fn codemap(&mut self) -> &mut CachingCodemapView<'tcx> {
+    pub fn codemap(&mut self) -> &mut CachingCodemapView<'gcx> {
         &mut self.codemap
     }
 
@@ -195,9 +195,9 @@ impl<'a, 'tcx: 'a> StableHashingContext<'a, 'tcx> {
 }
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::NodeId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ast::NodeId {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         match hcx.node_id_hashing_mode {
             NodeIdHashingMode::Ignore => {
@@ -230,7 +230,7 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::NodeId {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for Span {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for Span {
 
     // Hash a span in a stable way. We can't directly hash the span's BytePos
     // fields (that would be similar to hashing pointers, since those are just
@@ -242,7 +242,7 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for Span {
     // Also, hashing filenames is expensive so we avoid doing it twice when the
     // span starts and ends in the same file, which is almost always the case.
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use syntax_pos::Pos;
 
@@ -305,15 +305,16 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for Span {
     }
 }
 
-pub fn hash_stable_hashmap<'a, 'tcx, K, V, R, SK, F, W>(hcx: &mut StableHashingContext<'a, 'tcx>,
-                                                        hasher: &mut StableHasher<W>,
-                                                        map: &HashMap<K, V, R>,
-                                                        extract_stable_key: F)
+pub fn hash_stable_hashmap<'a, 'gcx, 'tcx, K, V, R, SK, F, W>(
+    hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
+    hasher: &mut StableHasher<W>,
+    map: &HashMap<K, V, R>,
+    extract_stable_key: F)
     where K: Eq + std_hash::Hash,
-          V: HashStable<StableHashingContext<'a, 'tcx>>,
+          V: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
           R: std_hash::BuildHasher,
-          SK: HashStable<StableHashingContext<'a, 'tcx>> + Ord + Clone,
-          F: Fn(&mut StableHashingContext<'a, 'tcx>, &K) -> SK,
+          SK: HashStable<StableHashingContext<'a, 'gcx, 'tcx>> + Ord + Clone,
+          F: Fn(&mut StableHashingContext<'a, 'gcx, 'tcx>, &K) -> SK,
           W: StableHasherResult,
 {
     let mut keys: Vec<_> = map.keys()
@@ -327,14 +328,15 @@ pub fn hash_stable_hashmap<'a, 'tcx, K, V, R, SK, F, W>(hcx: &mut StableHashingC
     }
 }
 
-pub fn hash_stable_hashset<'a, 'tcx, K, R, SK, F, W>(hcx: &mut StableHashingContext<'a, 'tcx>,
-                                                     hasher: &mut StableHasher<W>,
-                                                     set: &HashSet<K, R>,
-                                                     extract_stable_key: F)
+pub fn hash_stable_hashset<'a, 'tcx, 'gcx, K, R, SK, F, W>(
+    hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
+    hasher: &mut StableHasher<W>,
+    set: &HashSet<K, R>,
+    extract_stable_key: F)
     where K: Eq + std_hash::Hash,
           R: std_hash::BuildHasher,
-          SK: HashStable<StableHashingContext<'a, 'tcx>> + Ord + Clone,
-          F: Fn(&mut StableHashingContext<'a, 'tcx>, &K) -> SK,
+          SK: HashStable<StableHashingContext<'a, 'gcx, 'tcx>> + Ord + Clone,
+          F: Fn(&mut StableHashingContext<'a, 'gcx, 'tcx>, &K) -> SK,
           W: StableHasherResult,
 {
     let mut keys: Vec<_> = set.iter()
@@ -344,10 +346,11 @@ pub fn hash_stable_hashset<'a, 'tcx, K, R, SK, F, W>(hcx: &mut StableHashingCont
     keys.hash_stable(hcx, hasher);
 }
 
-pub fn hash_stable_nodemap<'a, 'tcx, V, W>(hcx: &mut StableHashingContext<'a, 'tcx>,
-                                           hasher: &mut StableHasher<W>,
-                                           map: &NodeMap<V>)
-    where V: HashStable<StableHashingContext<'a, 'tcx>>,
+pub fn hash_stable_nodemap<'a, 'tcx, 'gcx, V, W>(
+    hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
+    hasher: &mut StableHasher<W>,
+    map: &NodeMap<V>)
+    where V: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
           W: StableHasherResult,
 {
     hash_stable_hashmap(hcx, hasher, map, |hcx, node_id| {
@@ -356,14 +359,15 @@ pub fn hash_stable_nodemap<'a, 'tcx, V, W>(hcx: &mut StableHashingContext<'a, 't
 }
 
 
-pub fn hash_stable_btreemap<'a, 'tcx, K, V, SK, F, W>(hcx: &mut StableHashingContext<'a, 'tcx>,
-                                                      hasher: &mut StableHasher<W>,
-                                                      map: &BTreeMap<K, V>,
-                                                      extract_stable_key: F)
+pub fn hash_stable_btreemap<'a, 'tcx, 'gcx, K, V, SK, F, W>(
+    hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
+    hasher: &mut StableHasher<W>,
+    map: &BTreeMap<K, V>,
+    extract_stable_key: F)
     where K: Eq + Ord,
-          V: HashStable<StableHashingContext<'a, 'tcx>>,
-          SK: HashStable<StableHashingContext<'a, 'tcx>> + Ord + Clone,
-          F: Fn(&mut StableHashingContext<'a, 'tcx>, &K) -> SK,
+          V: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
+          SK: HashStable<StableHashingContext<'a, 'gcx, 'tcx>> + Ord + Clone,
+          F: Fn(&mut StableHashingContext<'a, 'gcx, 'tcx>, &K) -> SK,
           W: StableHasherResult,
 {
     let mut keys: Vec<_> = map.keys()
diff --git a/src/librustc/ich/impls_hir.rs b/src/librustc/ich/impls_hir.rs
index c582cac67e2..678ec797a86 100644
--- a/src/librustc/ich/impls_hir.rs
+++ b/src/librustc/ich/impls_hir.rs
@@ -21,20 +21,20 @@ use syntax::ast;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHasherResult};
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for DefId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for DefId {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         hcx.def_path_hash(*self).hash_stable(hcx, hasher);
     }
 }
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::HirId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::HirId {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::HirId {
             owner,
@@ -55,9 +55,9 @@ impl_stable_hash_for!(tuple_struct hir::ItemLocalId { index });
 // want to pick up on a reference changing its target, so we hash the NodeIds
 // in "DefPath Mode".
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::ItemId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::ItemId {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::ItemId {
             id
@@ -69,9 +69,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::ItemId {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::TraitItemId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::TraitItemId {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::TraitItemId {
             node_id
@@ -83,9 +83,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::TraitItemId {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::ImplItemId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::ImplItemId {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::ImplItemId {
             node_id
@@ -215,9 +215,9 @@ impl_stable_hash_for!(struct hir::TypeBinding {
     span
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Ty {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Ty {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let node_id_hashing_mode = match self.node {
             hir::TySlice(..)       |
@@ -299,9 +299,9 @@ impl_stable_hash_for!(enum hir::FunctionRetTy {
     Return(t)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::TraitRef {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::TraitRef {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::TraitRef {
             ref path,
@@ -338,9 +338,9 @@ impl_stable_hash_for!(struct hir::MacroDef {
 });
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Block {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Block {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::Block {
             ref stmts,
@@ -386,9 +386,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Block {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Pat {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Pat {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let node_id_hashing_mode = match self.node {
             hir::PatKind::Wild        |
@@ -529,9 +529,9 @@ impl_stable_hash_for!(enum hir::UnsafeSource {
     UserProvided
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Expr {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Expr {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         hcx.while_hashing_hir_bodies(true, |hcx| {
             let hir::Expr {
@@ -652,9 +652,9 @@ impl_stable_hash_for!(enum hir::LoopSource {
     ForLoop
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::MatchSource {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::MatchSource {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use hir::MatchSource;
 
@@ -703,9 +703,9 @@ impl_stable_hash_for!(enum hir::ScopeTarget {
     Loop(loop_id_result)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::Ident {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ast::Ident {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ast::Ident {
             ref name,
@@ -716,9 +716,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::Ident {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::TraitItem {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::TraitItem {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::TraitItem {
             id,
@@ -749,9 +749,9 @@ impl_stable_hash_for!(enum hir::TraitItemKind {
     Type(bounds, rhs)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::ImplItem {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::ImplItem {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::ImplItem {
             id,
@@ -781,9 +781,9 @@ impl_stable_hash_for!(enum hir::ImplItemKind {
     Type(t)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Visibility {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Visibility {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -802,9 +802,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Visibility {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Defaultness {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Defaultness {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -823,9 +823,9 @@ impl_stable_hash_for!(enum hir::ImplPolarity {
     Negative
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Mod {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Mod {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::Mod {
             inner,
@@ -878,9 +878,9 @@ impl_stable_hash_for!(enum hir::VariantData {
     Unit(id)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::Item {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::Item {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let node_id_hashing_mode = match self.node {
             hir::ItemExternCrate(..) |
@@ -961,9 +961,10 @@ impl_stable_hash_for!(struct hir::ImplItemRef {
     defaultness
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::AssociatedItemKind {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for hir::AssociatedItemKind {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -1008,9 +1009,9 @@ impl_stable_hash_for!(struct hir::Body {
     value
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::BodyId {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::BodyId {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         if hcx.hash_bodies() {
             hcx.tcx().hir.body(*self).hash_stable(hcx, hasher);
@@ -1024,9 +1025,9 @@ impl_stable_hash_for!(struct hir::InlineAsmOutput {
     is_indirect
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::GlobalAsm {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::GlobalAsm {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::GlobalAsm {
             asm,
@@ -1037,9 +1038,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::GlobalAsm {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::InlineAsm {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for hir::InlineAsm {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::InlineAsm {
             asm,
@@ -1114,10 +1115,11 @@ impl_stable_hash_for!(enum hir::Constness {
     NotConst
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for hir::def_id::DefIndex {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for hir::def_id::DefIndex {
 
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         DefId::local(*self).hash_stable(hcx, hasher);
     }
@@ -1129,9 +1131,10 @@ impl_stable_hash_for!(struct hir::def::Export {
     span
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::middle::lang_items::LangItem {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ::middle::lang_items::LangItem {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          _: &mut StableHashingContext<'a, 'tcx>,
+                                          _: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         ::std::hash::Hash::hash(self, hasher);
     }
diff --git a/src/librustc/ich/impls_mir.rs b/src/librustc/ich/impls_mir.rs
index edaeb596fe5..ae2bea3027d 100644
--- a/src/librustc/ich/impls_mir.rs
+++ b/src/librustc/ich/impls_mir.rs
@@ -32,10 +32,11 @@ impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
 impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref });
 impl_stable_hash_for!(struct mir::BasicBlockData<'tcx> { statements, terminator, is_cleanup });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Terminator<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::Terminator<'tcx> {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let mir::Terminator {
             ref kind,
@@ -72,59 +73,61 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Terminator<'t
 }
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Local {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Local {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use rustc_data_structures::indexed_vec::Idx;
         self.index().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::BasicBlock {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::BasicBlock {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use rustc_data_structures::indexed_vec::Idx;
         self.index().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Field {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Field {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use rustc_data_structures::indexed_vec::Idx;
         self.index().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::VisibilityScope {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::VisibilityScope {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use rustc_data_structures::indexed_vec::Idx;
         self.index().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Promoted {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Promoted {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use rustc_data_structures::indexed_vec::Idx;
         self.index().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::TerminatorKind<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::TerminatorKind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -182,9 +185,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::TerminatorKin
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::AssertMessage<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::AssertMessage<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -202,9 +206,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::AssertMessage
 
 impl_stable_hash_for!(struct mir::Statement<'tcx> { source_info, kind });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::StatementKind<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::StatementKind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -231,9 +236,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::StatementKind
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Lvalue<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Lvalue<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -250,12 +255,13 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Lvalue<'tcx>
     }
 }
 
-impl<'a, 'tcx, B, V> HashStable<StableHashingContext<'a, 'tcx>> for mir::Projection<'tcx, B, V>
-    where B: HashStable<StableHashingContext<'a, 'tcx>>,
-          V: HashStable<StableHashingContext<'a, 'tcx>>
+impl<'a, 'gcx, 'tcx, B, V> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::Projection<'tcx, B, V>
+    where B: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
+          V: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let mir::Projection {
             ref base,
@@ -267,11 +273,12 @@ impl<'a, 'tcx, B, V> HashStable<StableHashingContext<'a, 'tcx>> for mir::Project
     }
 }
 
-impl<'a, 'tcx, V> HashStable<StableHashingContext<'a, 'tcx>> for mir::ProjectionElem<'tcx, V>
-    where V: HashStable<StableHashingContext<'a, 'tcx>>
+impl<'a, 'gcx, 'tcx, V> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::ProjectionElem<'tcx, V>
+    where V: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -302,9 +309,9 @@ impl<'a, 'tcx, V> HashStable<StableHashingContext<'a, 'tcx>> for mir::Projection
 
 impl_stable_hash_for!(struct mir::VisibilityScopeData { span, parent_scope });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Operand<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Operand<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -319,9 +326,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Operand<'tcx>
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Rvalue<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Rvalue<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
 
@@ -379,9 +386,10 @@ impl_stable_hash_for!(enum mir::CastKind {
     Unsize
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::AggregateKind<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for mir::AggregateKind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -435,9 +443,9 @@ impl_stable_hash_for!(enum mir::NullOp {
 
 impl_stable_hash_for!(struct mir::Constant<'tcx> { span, ty, literal });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for mir::Literal<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for mir::Literal<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
diff --git a/src/librustc/ich/impls_syntax.rs b/src/librustc/ich/impls_syntax.rs
index f6ad97445e8..995f797df2f 100644
--- a/src/librustc/ich/impls_syntax.rs
+++ b/src/librustc/ich/impls_syntax.rs
@@ -27,20 +27,21 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHasherResult};
 use rustc_data_structures::accumulate_vec::AccumulateVec;
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::syntax::symbol::InternedString {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ::syntax::symbol::InternedString {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let s: &str = &**self;
         s.hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::Name {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ast::Name {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         self.as_str().hash_stable(hcx, hasher);
     }
@@ -82,9 +83,10 @@ impl_stable_hash_for!(enum ::syntax::abi::Abi {
 impl_stable_hash_for!(struct ::syntax::attr::Deprecation { since, note });
 impl_stable_hash_for!(struct ::syntax::attr::Stability { level, feature, rustc_depr });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::syntax::attr::StabilityLevel {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ::syntax::attr::StabilityLevel {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -135,9 +137,9 @@ impl_stable_hash_for!(struct ::syntax::ast::Lifetime { id, span, ident });
 impl_stable_hash_for!(enum ::syntax::ast::StrStyle { Cooked, Raw(pounds) });
 impl_stable_hash_for!(enum ::syntax::ast::AttrStyle { Outer, Inner });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for [ast::Attribute] {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for [ast::Attribute] {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         // Some attributes are always ignored during hashing.
         let filtered: AccumulateVec<[&ast::Attribute; 8]> = self
@@ -155,9 +157,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for [ast::Attribute] {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::Attribute {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ast::Attribute {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         // Make sure that these have been filtered out.
         debug_assert!(self.name().map(|name| !hcx.is_ignored_attr(name)).unwrap_or(true));
@@ -184,9 +186,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ast::Attribute {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for tokenstream::TokenTree {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for tokenstream::TokenTree {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -205,9 +208,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for tokenstream::Token
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for tokenstream::TokenStream {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for tokenstream::TokenStream {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         for sub_tt in self.trees() {
             sub_tt.hash_stable(hcx, hasher);
@@ -215,8 +219,8 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for tokenstream::Token
     }
 }
 
-fn hash_token<'a, 'tcx, W: StableHasherResult>(token: &token::Token,
-                                               hcx: &mut StableHashingContext<'a, 'tcx>,
+fn hash_token<'a, 'gcx, 'tcx, W: StableHasherResult>(token: &token::Token,
+                                               hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                                hasher: &mut StableHasher<W>,
                                                error_reporting_span: Span) {
     mem::discriminant(token).hash_stable(hcx, hasher);
@@ -322,9 +326,9 @@ impl_stable_hash_for!(enum ::syntax::ast::MetaItemKind {
     NameValue(lit)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for FileMap {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for FileMap {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let FileMap {
             ref name,
diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs
index a362dc31ff1..4e78d79ef87 100644
--- a/src/librustc/ich/impls_ty.rs
+++ b/src/librustc/ich/impls_ty.rs
@@ -19,27 +19,30 @@ use std::mem;
 use syntax_pos::symbol::InternedString;
 use ty;
 
-impl<'a, 'tcx, T> HashStable<StableHashingContext<'a, 'tcx>> for &'tcx ty::Slice<T>
-    where T: HashStable<StableHashingContext<'a, 'tcx>> {
+impl<'a, 'gcx, 'tcx, T> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for &'tcx ty::Slice<T>
+    where T: HashStable<StableHashingContext<'a, 'gcx, 'tcx>> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         (&self[..]).hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::subst::Kind<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::subst::Kind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         self.as_type().hash_stable(hcx, hasher);
         self.as_region().hash_stable(hcx, hasher);
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::RegionKind {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::RegionKind {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -72,9 +75,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::RegionKind {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::adjustment::AutoBorrow<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::adjustment::AutoBorrow<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -89,9 +93,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::adjustment::Au
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::adjustment::Adjust<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::adjustment::Adjust<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -122,9 +127,10 @@ impl_stable_hash_for!(enum ty::BorrowKind {
     MutBorrow
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::UpvarCapture<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::UpvarCapture<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -143,11 +149,11 @@ impl_stable_hash_for!(struct ty::FnSig<'tcx> {
     abi
 });
 
-impl<'a, 'tcx, T> HashStable<StableHashingContext<'a, 'tcx>> for ty::Binder<T>
-    where T: HashStable<StableHashingContext<'a, 'tcx>> + ty::fold::TypeFoldable<'tcx>
+impl<'a, 'gcx, 'tcx, T> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ty::Binder<T>
+    where T: HashStable<StableHashingContext<'a, 'gcx, 'tcx>> + ty::fold::TypeFoldable<'tcx>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         hcx.tcx().anonymize_late_bound_regions(self).0.hash_stable(hcx, hasher);
     }
@@ -166,12 +172,13 @@ impl_stable_hash_for!(struct ty::TraitPredicate<'tcx> { trait_ref });
 impl_stable_hash_for!(tuple_struct ty::EquatePredicate<'tcx> { t1, t2 });
 impl_stable_hash_for!(struct ty::SubtypePredicate<'tcx> { a_is_expected, a, b });
 
-impl<'a, 'tcx, A, B> HashStable<StableHashingContext<'a, 'tcx>> for ty::OutlivesPredicate<A, B>
-    where A: HashStable<StableHashingContext<'a, 'tcx>>,
-          B: HashStable<StableHashingContext<'a, 'tcx>>,
+impl<'a, 'gcx, 'tcx, A, B> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::OutlivesPredicate<A, B>
+    where A: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
+          B: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>,
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::OutlivesPredicate(ref a, ref b) = *self;
         a.hash_stable(hcx, hasher);
@@ -183,9 +190,9 @@ impl_stable_hash_for!(struct ty::ProjectionPredicate<'tcx> { projection_ty, ty }
 impl_stable_hash_for!(struct ty::ProjectionTy<'tcx> { trait_ref, item_def_id });
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::Predicate<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ty::Predicate<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -221,9 +228,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::Predicate<'tcx
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::AdtFlags {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ty::AdtFlags {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          _: &mut StableHashingContext<'a, 'tcx>,
+                                          _: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         std_hash::Hash::hash(self, hasher);
     }
@@ -248,10 +255,10 @@ impl_stable_hash_for!(struct ty::FieldDef {
     vis
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>>
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 for ::middle::const_val::ConstVal<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use middle::const_val::ConstVal;
 
@@ -324,9 +331,9 @@ impl_stable_hash_for!(enum ty::adjustment::CustomCoerceUnsized {
     Struct(index)
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::Generics {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ty::Generics {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::Generics {
             parent,
@@ -350,9 +357,10 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::Generics {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::RegionParameterDef {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::RegionParameterDef {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::RegionParameterDef {
             name,
@@ -379,12 +387,12 @@ impl_stable_hash_for!(struct ty::TypeParameterDef {
 });
 
 
-impl<'a, 'tcx, T> HashStable<StableHashingContext<'a, 'tcx>>
+impl<'a, 'gcx, 'tcx, T> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 for ::middle::resolve_lifetime::Set1<T>
-    where T: HashStable<StableHashingContext<'a, 'tcx>>
+    where T: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use middle::resolve_lifetime::Set1;
 
@@ -427,10 +435,11 @@ impl_stable_hash_for!(enum ty::cast::CastKind {
     FnPtrAddrCast
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::middle::region::CodeExtent
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ::middle::region::CodeExtent
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use middle::region::CodeExtent;
 
@@ -472,10 +481,11 @@ impl_stable_hash_for!(enum ty::BoundRegion {
     BrEnv
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::TypeVariants<'tcx>
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::TypeVariants<'tcx>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         use ty::TypeVariants::*;
 
@@ -563,10 +573,11 @@ impl_stable_hash_for!(struct ty::TypeAndMut<'tcx> {
     mutbl
 });
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::ExistentialPredicate<'tcx>
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::ExistentialPredicate<'tcx>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
@@ -595,9 +606,10 @@ impl_stable_hash_for!(struct ty::ExistentialProjection<'tcx> {
 });
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::TypeckTables<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
+for ty::TypeckTables<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::TypeckTables {
             ref type_dependent_defs,
diff --git a/src/librustc/macros.rs b/src/librustc/macros.rs
index c18e585f795..f814f941b06 100644
--- a/src/librustc/macros.rs
+++ b/src/librustc/macros.rs
@@ -73,10 +73,10 @@ macro_rules! __impl_stable_hash_field {
 #[macro_export]
 macro_rules! impl_stable_hash_for {
     (enum $enum_name:path { $( $variant:ident $( ( $($arg:ident),* ) )* ),* }) => {
-        impl<'a, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'tcx>> for $enum_name {
+        impl<'a, 'gcx, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'gcx, 'tcx>> for $enum_name {
             #[inline]
             fn hash_stable<W: ::rustc_data_structures::stable_hasher::StableHasherResult>(&self,
-                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'tcx>,
+                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'gcx, 'tcx>,
                                                   __hasher: &mut ::rustc_data_structures::stable_hasher::StableHasher<W>) {
                 use $enum_name::*;
                 ::std::mem::discriminant(self).hash_stable(__ctx, __hasher);
@@ -92,10 +92,10 @@ macro_rules! impl_stable_hash_for {
         }
     };
     (struct $struct_name:path { $($field:ident),* }) => {
-        impl<'a, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'tcx>> for $struct_name {
+        impl<'a, 'gcx, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'gcx, 'tcx>> for $struct_name {
             #[inline]
             fn hash_stable<W: ::rustc_data_structures::stable_hasher::StableHasherResult>(&self,
-                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'tcx>,
+                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'gcx, 'tcx>,
                                                   __hasher: &mut ::rustc_data_structures::stable_hasher::StableHasher<W>) {
                 let $struct_name {
                     $(ref $field),*
@@ -106,10 +106,10 @@ macro_rules! impl_stable_hash_for {
         }
     };
     (tuple_struct $struct_name:path { $($field:ident),* }) => {
-        impl<'a, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'tcx>> for $struct_name {
+        impl<'a, 'gcx, 'tcx> ::rustc_data_structures::stable_hasher::HashStable<$crate::ich::StableHashingContext<'a, 'gcx, 'tcx>> for $struct_name {
             #[inline]
             fn hash_stable<W: ::rustc_data_structures::stable_hasher::StableHasherResult>(&self,
-                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'tcx>,
+                                                  __ctx: &mut $crate::ich::StableHashingContext<'a, 'gcx, 'tcx>,
                                                   __hasher: &mut ::rustc_data_structures::stable_hasher::StableHasher<W>) {
                 let $struct_name (
                     $(ref $field),*
@@ -125,11 +125,11 @@ macro_rules! impl_stable_hash_for {
 macro_rules! impl_stable_hash_for_spanned {
     ($T:path) => (
 
-        impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ::syntax::codemap::Spanned<$T>
+        impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ::syntax::codemap::Spanned<$T>
         {
             #[inline]
             fn hash_stable<W: StableHasherResult>(&self,
-                                                  hcx: &mut StableHashingContext<'a, 'tcx>,
+                                                  hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                                   hasher: &mut StableHasher<W>) {
                 self.node.hash_stable(hcx, hasher);
                 self.span.hash_stable(hcx, hasher);
diff --git a/src/librustc/mir/cache.rs b/src/librustc/mir/cache.rs
index 799686ceca4..73c702fedb8 100644
--- a/src/librustc/mir/cache.rs
+++ b/src/librustc/mir/cache.rs
@@ -35,9 +35,9 @@ impl serialize::Decodable for Cache {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for Cache {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for Cache {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          _: &mut StableHashingContext<'a, 'tcx>,
+                                          _: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           _: &mut StableHasher<W>) {
         // do nothing
     }
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 653021119aa..afa2da3d561 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -465,9 +465,9 @@ impl<'tcx> Hash for TyS<'tcx> {
     }
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for ty::TyS<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for ty::TyS<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::TyS {
             ref sty,
@@ -1318,9 +1318,9 @@ impl<'tcx> serialize::UseSpecializedEncodable for &'tcx AdtDef {
 impl<'tcx> serialize::UseSpecializedDecodable for &'tcx AdtDef {}
 
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for AdtDef {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for AdtDef {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let ty::AdtDef {
             did,
diff --git a/src/librustc_incremental/calculate_svh/mod.rs b/src/librustc_incremental/calculate_svh/mod.rs
index be4d610a895..7831ae3092f 100644
--- a/src/librustc_incremental/calculate_svh/mod.rs
+++ b/src/librustc_incremental/calculate_svh/mod.rs
@@ -94,7 +94,7 @@ impl<'a> ::std::ops::Index<&'a DepNode<DefId>> for IncrementalHashesMap {
 }
 
 struct ComputeItemHashesVisitor<'a, 'tcx: 'a> {
-    hcx: StableHashingContext<'a, 'tcx>,
+    hcx: StableHashingContext<'a, 'tcx, 'tcx>,
     hashes: IncrementalHashesMap,
 }
 
@@ -103,7 +103,7 @@ impl<'a, 'tcx: 'a> ComputeItemHashesVisitor<'a, 'tcx> {
                                               dep_node: DepNode<DefId>,
                                               hash_bodies: bool,
                                               item_like: T)
-        where T: HashStable<StableHashingContext<'a, 'tcx>>
+        where T: HashStable<StableHashingContext<'a, 'tcx, 'tcx>>
     {
         if !hash_bodies && !self.hcx.tcx().sess.opts.build_dep_graph() {
             // If we just need the hashes in order to compute the SVH, we don't
diff --git a/src/librustc_metadata/isolated_encoder.rs b/src/librustc_metadata/isolated_encoder.rs
index ed1680fbfae..c4116489357 100644
--- a/src/librustc_metadata/isolated_encoder.rs
+++ b/src/librustc_metadata/isolated_encoder.rs
@@ -23,7 +23,7 @@ use rustc_serialize::Encodable;
 pub struct IsolatedEncoder<'a, 'b: 'a, 'tcx: 'b> {
     pub tcx: TyCtxt<'b, 'tcx, 'tcx>,
     ecx: &'a mut EncodeContext<'b, 'tcx>,
-    hcx: Option<(StableHashingContext<'b, 'tcx>, StableHasher<Fingerprint>)>,
+    hcx: Option<(StableHashingContext<'b, 'tcx, 'tcx>, StableHasher<Fingerprint>)>,
 }
 
 impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
@@ -61,7 +61,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
     }
 
     pub fn lazy<T>(&mut self, value: &T) -> Lazy<T>
-        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx>>
+        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx, 'tcx>>
     {
         if let Some((ref mut hcx, ref mut hasher)) = self.hcx {
             value.hash_stable(hcx, hasher);
@@ -72,7 +72,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
 
     pub fn lazy_seq<I, T>(&mut self, iter: I) -> LazySeq<T>
         where I: IntoIterator<Item = T>,
-              T: Encodable + HashStable<StableHashingContext<'b, 'tcx>>
+              T: Encodable + HashStable<StableHashingContext<'b, 'tcx, 'tcx>>
     {
         if let Some((ref mut hcx, ref mut hasher)) = self.hcx {
             let iter = iter.into_iter();
@@ -111,7 +111,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
 
     pub fn lazy_seq_ref<'x, I, T>(&mut self, iter: I) -> LazySeq<T>
         where I: IntoIterator<Item = &'x T>,
-              T: 'x + Encodable + HashStable<StableHashingContext<'b, 'tcx>>
+              T: 'x + Encodable + HashStable<StableHashingContext<'b, 'tcx, 'tcx>>
     {
         if let Some((ref mut hcx, ref mut hasher)) = self.hcx {
             let iter = iter.into_iter();
@@ -149,7 +149,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
     }
 
     pub fn lazy_seq_from_slice<T>(&mut self, slice: &[T]) -> LazySeq<T>
-        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx>>
+        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx, 'tcx>>
     {
         if let Some((ref mut hcx, ref mut hasher)) = self.hcx {
             slice.hash_stable(hcx, hasher);
@@ -159,7 +159,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
     }
 
     pub fn lazy_seq_ref_from_slice<T>(&mut self, slice: &[&T]) -> LazySeq<T>
-        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx>>
+        where T: Encodable + HashStable<StableHashingContext<'b, 'tcx, 'tcx>>
     {
         if let Some((ref mut hcx, ref mut hasher)) = self.hcx {
             slice.hash_stable(hcx, hasher);
diff --git a/src/librustc_metadata/schema.rs b/src/librustc_metadata/schema.rs
index 2ffe7cc02aa..9180f9100ad 100644
--- a/src/librustc_metadata/schema.rs
+++ b/src/librustc_metadata/schema.rs
@@ -221,11 +221,11 @@ impl<T> Tracked<T> {
     }
 }
 
-impl<'a, 'tcx, T> HashStable<StableHashingContext<'a, 'tcx>> for Tracked<T>
-    where T: HashStable<StableHashingContext<'a, 'tcx>>
+impl<'a, 'gcx, 'tcx, T> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for Tracked<T>
+    where T: HashStable<StableHashingContext<'a, 'gcx, 'tcx>>
 {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let Tracked {
             ref state
@@ -277,9 +277,9 @@ pub struct TraitImpls {
     pub impls: LazySeq<DefIndex>,
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for TraitImpls {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for TraitImpls {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         let TraitImpls {
             trait_id: (krate, def_index),
@@ -359,9 +359,9 @@ pub enum EntryKind<'tcx> {
     AssociatedConst(AssociatedContainer, u8),
 }
 
-impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for EntryKind<'tcx> {
+impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for EntryKind<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
-                                          hcx: &mut StableHashingContext<'a, 'tcx>,
+                                          hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {