rustc: Hide the `named_region_map` behind queries

This commit makes the `named_region_map` field of `GlobalCtxt` private by
encapsulating the fields behind new queries, and the new queries are also
targeted at particular `HirId` nodes instead of accessing the entire map.

7 files changed, 95 insertions, 41 deletions

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 9646d3a7b3b..3efba6a5f22 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -550,6 +550,10 @@ define_dep_nodes!( <'tcx>
     [] IsStaticallyIncludedForeignItem(DefId),
     [] NativeLibraryKind(DefId),
     [] LinkArgs,
+
+    [] NamedRegion(HirId),
+    [] IsLateBound(HirId),
+    [] ObjectLifetimeDefaults(HirId),
 );
 
 trait DepNodeParams<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> : fmt::Debug {
diff --git a/src/librustc/infer/error_reporting/anon_anon_conflict.rs b/src/librustc/infer/error_reporting/anon_anon_conflict.rs
index c80ce3c96f1..d3fff4c66af 100644
--- a/src/librustc/infer/error_reporting/anon_anon_conflict.rs
+++ b/src/librustc/infer/error_reporting/anon_anon_conflict.rs
@@ -209,18 +209,19 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
 
         match arg.node {
             hir::TyRptr(ref lifetime, _) => {
-                match self.infcx.tcx.named_region_map.defs.get(&lifetime.id) {
+                let hir_id = self.infcx.tcx.hir.node_to_hir_id(lifetime.id);
+                match self.infcx.tcx.named_region(hir_id) {
                     // the lifetime of the TyRptr
-                    Some(&rl::Region::LateBoundAnon(debruijn_index, anon_index)) => {
+                    Some(rl::Region::LateBoundAnon(debruijn_index, anon_index)) => {
                         if debruijn_index.depth == 1 && anon_index == br_index {
                             self.found_type = Some(arg);
                             return; // we can stop visiting now
                         }
                     }
-                    Some(&rl::Region::Static) |
-                    Some(&rl::Region::EarlyBound(_, _)) |
-                    Some(&rl::Region::LateBound(_, _)) |
-                    Some(&rl::Region::Free(_, _)) |
+                    Some(rl::Region::Static) |
+                    Some(rl::Region::EarlyBound(_, _)) |
+                    Some(rl::Region::LateBound(_, _)) |
+                    Some(rl::Region::Free(_, _)) |
                     None => {
                         debug!("no arg found");
                     }
@@ -272,17 +273,18 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for TyPathVisitor<'a, 'gcx, 'tcx> {
             _ => return,
         };
 
-        match self.infcx.tcx.named_region_map.defs.get(&lifetime.id) {
+        let hir_id = self.infcx.tcx.hir.node_to_hir_id(lifetime.id);
+        match self.infcx.tcx.named_region(hir_id) {
             // the lifetime of the TyPath!
-            Some(&rl::Region::LateBoundAnon(debruijn_index, anon_index)) => {
+            Some(rl::Region::LateBoundAnon(debruijn_index, anon_index)) => {
                 if debruijn_index.depth == 1 && anon_index == br_index {
                     self.found_it = true;
                 }
             }
-            Some(&rl::Region::Static) |
-            Some(&rl::Region::EarlyBound(_, _)) |
-            Some(&rl::Region::LateBound(_, _)) |
-            Some(&rl::Region::Free(_, _)) |
+            Some(rl::Region::Static) |
+            Some(rl::Region::EarlyBound(_, _)) |
+            Some(rl::Region::LateBound(_, _)) |
+            Some(rl::Region::Free(_, _)) |
             None => {
                 debug!("no arg found");
             }
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 0b9bf9a708a..f2e40e3693a 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -23,7 +23,7 @@ use lint::{self, Lint};
 use ich::{self, StableHashingContext, NodeIdHashingMode};
 use middle::free_region::FreeRegionMap;
 use middle::lang_items;
-use middle::resolve_lifetime;
+use middle::resolve_lifetime::{self, ObjectLifetimeDefault};
 use middle::stability;
 use mir::Mir;
 use mir::transform::Passes;
@@ -822,7 +822,7 @@ pub struct GlobalCtxt<'tcx> {
     /// Export map produced by name resolution.
     export_map: FxHashMap<HirId, Rc<Vec<Export>>>,
 
-    pub named_region_map: resolve_lifetime::NamedRegionMap,
+    named_region_map: NamedRegionMap,
 
     pub hir: hir_map::Map<'tcx>,
 
@@ -1054,7 +1054,23 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             global_interners: interners,
             dep_graph: dep_graph.clone(),
             types: common_types,
-            named_region_map,
+            named_region_map: NamedRegionMap {
+                defs:
+                    named_region_map.defs
+                        .into_iter()
+                        .map(|(k, v)| (hir.node_to_hir_id(k), v))
+                        .collect(),
+                late_bound:
+                    named_region_map.late_bound
+                        .into_iter()
+                        .map(|k| hir.node_to_hir_id(k))
+                        .collect(),
+                object_lifetime_defaults:
+                    named_region_map.object_lifetime_defaults
+                        .into_iter()
+                        .map(|(k, v)| (hir.node_to_hir_id(k), Rc::new(v)))
+                        .collect(),
+            },
             trait_map: resolutions.trait_map.into_iter().map(|(k, v)| {
                 (hir.node_to_hir_id(k), Rc::new(v))
             }).collect(),
@@ -1978,19 +1994,18 @@ impl<T, R, E> InternIteratorElement<T, R> for Result<T, E> {
     }
 }
 
-fn in_scope_traits<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: HirId)
-    -> Option<Rc<Vec<TraitCandidate>>>
-{
-    tcx.gcx.trait_map.get(&id).cloned()
-}
-
-fn module_exports<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: HirId)
-    -> Option<Rc<Vec<Export>>>
-{
-    tcx.gcx.export_map.get(&id).cloned()
+struct NamedRegionMap {
+    defs: FxHashMap<HirId, resolve_lifetime::Region>,
+    late_bound: FxHashSet<HirId>,
+    object_lifetime_defaults: FxHashMap<HirId, Rc<Vec<ObjectLifetimeDefault>>>,
 }
 
 pub fn provide(providers: &mut ty::maps::Providers) {
-    providers.in_scope_traits = in_scope_traits;
-    providers.module_exports = module_exports;
+    providers.in_scope_traits = |tcx, id| tcx.gcx.trait_map.get(&id).cloned();
+    providers.module_exports = |tcx, id| tcx.gcx.export_map.get(&id).cloned();
+    providers.named_region = |tcx, id| tcx.gcx.named_region_map.defs.get(&id).cloned();
+    providers.is_late_bound = |tcx, id| tcx.gcx.named_region_map.late_bound.contains(&id);
+    providers.object_lifetime_defaults = |tcx, id| {
+        tcx.gcx.named_region_map.object_lifetime_defaults.get(&id).cloned()
+    };
 }
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 1312bd3a7a6..d4bd434add4 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -20,6 +20,8 @@ use middle::cstore::{ExternCrate, LinkagePreference, NativeLibrary};
 use middle::cstore::NativeLibraryKind;
 use middle::privacy::AccessLevels;
 use middle::region;
+use middle::region::RegionMaps;
+use middle::resolve_lifetime::{Region, ObjectLifetimeDefault};
 use mir;
 use mir::transform::{MirSuite, MirPassIndex};
 use session::CompileResult;
@@ -649,6 +651,24 @@ impl<'tcx> QueryDescription for queries::link_args<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::named_region<'tcx> {
+    fn describe(_tcx: TyCtxt, _: HirId) -> String {
+        format!("fetching info about a named region")
+    }
+}
+
+impl<'tcx> QueryDescription for queries::is_late_bound<'tcx> {
+    fn describe(_tcx: TyCtxt, _: HirId) -> String {
+        format!("testing whether a lifetime is late bound")
+    }
+}
+
+impl<'tcx> QueryDescription for queries::object_lifetime_defaults<'tcx> {
+    fn describe(_tcx: TyCtxt, _: HirId) -> String {
+        format!("fetching a list of ObjectLifetimeDefault for a lifetime")
+    }
+}
+
 // If enabled, send a message to the profile-queries thread
 macro_rules! profq_msg {
     ($tcx:expr, $msg:expr) => {
@@ -1243,6 +1263,11 @@ define_maps! { <'tcx>
     [] native_library_kind: NativeLibraryKind(DefId)
         -> Option<NativeLibraryKind>,
     [] link_args: link_args_node(CrateNum) -> Rc<Vec<String>>,
+
+    [] named_region: NamedRegion(HirId) -> Option<Region>,
+    [] is_late_bound: IsLateBound(HirId) -> bool,
+    [] object_lifetime_defaults: ObjectLifetimeDefaults(HirId)
+        -> Option<Rc<Vec<ObjectLifetimeDefault>>>,
 }
 
 fn type_param_predicates<'tcx>((item_id, param_id): (DefId, DefId)) -> DepConstructor<'tcx> {
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index ee1e6bd950f..f391c2f9279 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -96,22 +96,23 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
         -> ty::Region<'tcx>
     {
         let tcx = self.tcx();
-        let r = match tcx.named_region_map.defs.get(&lifetime.id) {
-            Some(&rl::Region::Static) => {
+        let hir_id = tcx.hir.node_to_hir_id(lifetime.id);
+        let r = match tcx.named_region(hir_id) {
+            Some(rl::Region::Static) => {
                 tcx.types.re_static
             }
 
-            Some(&rl::Region::LateBound(debruijn, id)) => {
+            Some(rl::Region::LateBound(debruijn, id)) => {
                 let name = tcx.hir.name(id);
                 tcx.mk_region(ty::ReLateBound(debruijn,
                     ty::BrNamed(tcx.hir.local_def_id(id), name)))
             }
 
-            Some(&rl::Region::LateBoundAnon(debruijn, index)) => {
+            Some(rl::Region::LateBoundAnon(debruijn, index)) => {
                 tcx.mk_region(ty::ReLateBound(debruijn, ty::BrAnon(index)))
             }
 
-            Some(&rl::Region::EarlyBound(index, id)) => {
+            Some(rl::Region::EarlyBound(index, id)) => {
                 let name = tcx.hir.name(id);
                 tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion {
                     def_id: tcx.hir.local_def_id(id),
@@ -120,7 +121,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                 }))
             }
 
-            Some(&rl::Region::Free(scope, id)) => {
+            Some(rl::Region::Free(scope, id)) => {
                 let name = tcx.hir.name(id);
                 tcx.mk_region(ty::ReFree(ty::FreeRegion {
                     scope,
@@ -627,7 +628,8 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
             self.ast_region_to_region(lifetime, None)
         } else {
             self.compute_object_lifetime_bound(span, existential_predicates).unwrap_or_else(|| {
-                if tcx.named_region_map.defs.contains_key(&lifetime.id) {
+                let hir_id = tcx.hir.node_to_hir_id(lifetime.id);
+                if tcx.named_region(hir_id).is_some() {
                     self.ast_region_to_region(lifetime, None)
                 } else {
                     self.re_infer(span, None).unwrap_or_else(|| {
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index c177623af48..38b72677bc6 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -812,7 +812,8 @@ fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
             if self.has_late_bound_regions.is_some() { return }
 
-            match self.tcx.named_region_map.defs.get(&lt.id).cloned() {
+            let hir_id = self.tcx.hir.node_to_hir_id(lt.id);
+            match self.tcx.named_region(hir_id) {
                 Some(rl::Region::Static) | Some(rl::Region::EarlyBound(..)) => {}
                 Some(rl::Region::LateBound(debruijn, _)) |
                 Some(rl::Region::LateBoundAnon(debruijn, _))
@@ -830,7 +831,8 @@ fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             tcx, binder_depth: 1, has_late_bound_regions: None
         };
         for lifetime in &generics.lifetimes {
-            if tcx.named_region_map.late_bound.contains(&lifetime.lifetime.id) {
+            let hir_id = tcx.hir.node_to_hir_id(lifetime.lifetime.id);
+            if tcx.is_late_bound(hir_id) {
                 return Some(lifetime.lifetime.span);
             }
         }
@@ -987,8 +989,8 @@ fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         }
     }).collect::<Vec<_>>();
 
-    let object_lifetime_defaults =
-        tcx.named_region_map.object_lifetime_defaults.get(&node_id);
+    let hir_id = tcx.hir.node_to_hir_id(node_id);
+    let object_lifetime_defaults = tcx.object_lifetime_defaults(hir_id);
 
     // Now create the real type parameters.
     let type_start = own_start + regions.len() as u32;
@@ -1014,7 +1016,7 @@ fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             def_id: tcx.hir.local_def_id(p.id),
             has_default: p.default.is_some(),
             object_lifetime_default:
-                object_lifetime_defaults.map_or(rl::Set1::Empty, |o| o[i]),
+                object_lifetime_defaults.as_ref().map_or(rl::Set1::Empty, |o| o[i]),
             pure_wrt_drop: p.pure_wrt_drop,
         }
     });
@@ -1343,7 +1345,10 @@ fn early_bound_lifetimes_from_generics<'a, 'tcx>(
     ast_generics
         .lifetimes
         .iter()
-        .filter(move |l| !tcx.named_region_map.late_bound.contains(&l.lifetime.id))
+        .filter(move |l| {
+            let hir_id = tcx.hir.node_to_hir_id(l.lifetime.id);
+            !tcx.is_late_bound(hir_id)
+        })
 }
 
 fn predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index aab44ddce0e..f446bf587bd 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -830,7 +830,8 @@ impl Lifetime {
 
 impl Clean<Lifetime> for hir::Lifetime {
     fn clean(&self, cx: &DocContext) -> Lifetime {
-        let def = cx.tcx.named_region_map.defs.get(&self.id).cloned();
+        let hir_id = cx.tcx.hir.node_to_hir_id(self.id);
+        let def = cx.tcx.named_region(hir_id);
         match def {
             Some(rl::Region::EarlyBound(_, node_id)) |
             Some(rl::Region::LateBound(_, node_id)) |