On-demandify region mapping

4 files changed, 38 insertions, 13 deletions

diff --git a/src/librustc/middle/free_region.rs b/src/librustc/middle/free_region.rs
index 2bfa8dec0bf..f622dfc683b 100644
--- a/src/librustc/middle/free_region.rs
+++ b/src/librustc/middle/free_region.rs
@@ -136,10 +136,10 @@ impl FreeRegionMap {
                     true,
 
                 (&ty::ReScope(sub_scope), &ty::ReScope(super_scope)) =>
-                    tcx.region_maps.is_subscope_of(sub_scope, super_scope),
+                    tcx.region_maps().is_subscope_of(sub_scope, super_scope),
 
                 (&ty::ReScope(sub_scope), &ty::ReFree(fr)) =>
-                    tcx.region_maps.is_subscope_of(sub_scope, fr.scope) ||
+                    tcx.region_maps().is_subscope_of(sub_scope, fr.scope) ||
                     self.is_static(fr),
 
                 (&ty::ReFree(sub_fr), &ty::ReFree(super_fr)) =>
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
index 63104678862..73c8d1db312 100644
--- a/src/librustc/middle/liveness.rs
+++ b/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(
-                self.ir.tcx.region_maps.call_site_extent(id, body.value.id),
+                self.ir.tcx.region_maps().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() {
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index 9db6dffb0e8..b398255aede 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -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: self.tcx().region_maps.item_extent(fn_body_id),
+            scope: self.tcx().region_maps().item_extent(fn_body_id),
             bound_region: ty::BrEnv
         }));
 
@@ -845,7 +845,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
     pub fn temporary_scope(&self, id: ast::NodeId) -> (&'tcx ty::Region, &'tcx ty::Region)
     {
         let (scope, old_scope) =
-            self.tcx().region_maps.old_and_new_temporary_scope(id);
+            self.tcx().region_maps().old_and_new_temporary_scope(id);
         (self.tcx().mk_region(match scope {
             Some(scope) => ty::ReScope(scope),
             None => ty::ReStatic
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index 0676075930d..18e76ff5011 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -16,7 +16,6 @@
 //! Most of the documentation on regions can be found in
 //! `middle/infer/region_inference/README.md`
 
-use dep_graph::DepNode;
 use hir::map as hir_map;
 use session::Session;
 use util::nodemap::{FxHashMap, NodeMap, NodeSet};
@@ -26,11 +25,15 @@ use std::cell::RefCell;
 use std::collections::hash_map::Entry;
 use std::fmt;
 use std::mem;
+use std::rc::Rc;
 use syntax::codemap;
 use syntax::ast::{self, NodeId};
 use syntax_pos::Span;
+use ty::TyCtxt;
+use ty::maps::Providers;
 
 use hir;
+use hir::def_id::{CrateNum, LOCAL_CRATE};
 use hir::intravisit::{self, Visitor, FnKind, NestedVisitorMap};
 use hir::{Block, Item, FnDecl, Arm, Pat, PatKind, Stmt, Expr, Local};
 
@@ -44,8 +47,13 @@ impl fmt::Debug for CodeExtent {
 
         ty::tls::with_opt(|opt_tcx| {
             if let Some(tcx) = opt_tcx {
-                if let Some(data) = tcx.region_maps.code_extents.borrow().get(self.0 as usize) {
-                    write!(f, "/{:?}", data)?;
+                let region_maps = tcx.region_maps();
+                {
+                    let code_extents = &region_maps.code_extents;
+                    if let Some(data) = code_extents.borrow().get(self.0 as usize) {
+                        write!(f, "/{:?}", data)?;
+                    }
+                    mem::drop(code_extents); // FIXME why is this necessary?
                 }
             }
             Ok(())
@@ -1256,9 +1264,19 @@ impl<'hir, 'a> Visitor<'hir> for RegionResolutionVisitor<'hir, 'a> {
     }
 }
 
-pub fn resolve_crate(sess: &Session, map: &hir_map::Map) -> RegionMaps {
-    let _task = map.dep_graph.in_task(DepNode::RegionResolveCrate);
-    let krate = map.krate();
+pub fn resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Rc<RegionMaps> {
+    tcx.region_resolve_crate(LOCAL_CRATE)
+}
+
+fn region_resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum)
+    -> Rc<RegionMaps>
+{
+    debug_assert!(crate_num == LOCAL_CRATE);
+
+    let sess = &tcx.sess;
+    let hir_map = &tcx.hir;
+
+    let krate = hir_map.krate();
 
     let maps = RegionMaps {
         code_extents: RefCell::new(vec![]),
@@ -1279,7 +1297,7 @@ pub fn resolve_crate(sess: &Session, map: &hir_map::Map) -> RegionMaps {
         let mut visitor = RegionResolutionVisitor {
             sess: sess,
             region_maps: &maps,
-            map: map,
+            map: hir_map,
             cx: Context {
                 root_id: None,
                 parent: ROOT_CODE_EXTENT,
@@ -1289,5 +1307,12 @@ pub fn resolve_crate(sess: &Session, map: &hir_map::Map) -> RegionMaps {
         };
         krate.visit_all_item_likes(&mut visitor.as_deep_visitor());
     }
-    return maps;
+    Rc::new(maps)
+}
+
+pub fn provide(providers: &mut Providers) {
+    *providers = Providers {
+        region_resolve_crate,
+        ..*providers
+    };
 }