patch.diff

diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index d1d5e9d..34fc383 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -1041,10 +1041,11 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>,
     }
 }
 
-fn resolve_item_like<'a, 'tcx, F>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, walk: F)
+/// Executes `walk` in a "cleared" context with no parents or
+/// anything.
+fn clear_cx<'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;
     let prev_ts = mem::replace(&mut visitor.terminating_scopes, NodeSet());
     visitor.cx = Context {
@@ -1160,15 +1161,28 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionResolutionVisitor<'a, 'tcx> {
     }
 
     fn visit_item(&mut self, i: &'tcx Item) {
-        resolve_item_like(self, |this| intravisit::walk_item(this, i));
+        clear_cx(self, |this| intravisit::walk_item(this, i));
     }
 
     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
-        resolve_item_like(self, |this| intravisit::walk_impl_item(this, ii));
+        clear_cx(self, |this| match ii.node {
+            hir::ImplItemKind::Const(_, body) => {
+                // Not a perfect fit, but it will do for now. In
+                // short, the "call site" for a constant is sort of
+                // place in which the result of evaluation will be
+                // used.
+                this.cx.parent = Some(this.new_code_extent(
+                    CodeExtentData::CallSiteScope { fn_id: ii.id,
+                                                    body_id: body.node_id }));
+
+                intravisit::walk_impl_item(this, ii);
+            }
+            _ => intravisit::walk_impl_item(this, ii)
+        });
     }
 
     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
-        resolve_item_like(self, |this| intravisit::walk_trait_item(this, ti));
+        clear_cx(self, |this| intravisit::walk_trait_item(this, ti));
     }
 
     fn visit_fn(&mut self, fk: FnKind<'tcx>, fd: &'tcx FnDecl,
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index b65de56..cdc6fff 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -1276,7 +1276,7 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
         match tcx.hir.find(id) {
             Some(hir_map::NodeImplItem(ref impl_item)) => {
                 match impl_item.node {
-                    hir::ImplItemKind::Type(_) | hir::ImplItemKind::Const(..) => {
+                    hir::ImplItemKind::Type(_) => {
                         // associated types don't have their own entry (for some reason),
                         // so for now just grab environment for the impl
                         let impl_id = tcx.hir.get_parent(id);
@@ -1285,6 +1285,16 @@ impl<'a, 'tcx> ParameterEnvironment<'tcx> {
                                                             impl_def_id,
                                                             Some(tcx.item_extent(id)))
                     }
+                    hir::ImplItemKind::Const(_, body) => {
+                        // associated types don't have their own entry (for some reason),
+                        // so for now just grab environment for the impl
+                        let impl_id = tcx.hir.get_parent(id);
+                        let impl_def_id = tcx.hir.local_def_id(impl_id);
+                        let extent = tcx.call_site_extent(id, body.node_id);
+                        tcx.construct_parameter_environment(impl_item.span,
+                                                            impl_def_id,
+                                                            Some(extent))
+                    }
                     hir::ImplItemKind::Method(_, ref body) => {
                         tcx.construct_parameter_environment(
                             impl_item.span,