From 4d7c0b68cf2df93158747180bef0c7c6724e4dd3 Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Wed, 3 May 2017 08:17:54 -0500
Subject: [PATCH 01/10] all queries use dep nodes

---
 src/librustc/dep_graph/dep_node.rs |  6 ++++++
 src/librustc/ty/maps.rs            | 10 +++-------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 37b8a56d916..1c71079e94b 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -154,6 +154,9 @@ pub enum DepNode<D: Clone + Debug> {
     DefSpan(D),
     Stability(D),
     Deprecation(D),
+    ItemBodyNestedBodies(D),
+    ConstIsRvaluePromotableToStatic(D),
+    IsMirAvailable(D),
 }
 
 impl<D: Clone + Debug> DepNode<D> {
@@ -264,6 +267,9 @@ impl<D: Clone + Debug> DepNode<D> {
             DefSpan(ref d) => op(d).map(DefSpan),
             Stability(ref d) => op(d).map(Stability),
             Deprecation(ref d) => op(d).map(Deprecation),
+            ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
+            ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
+            IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
         }
     }
 }
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 66df8dc050a..513240a4ec3 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -783,9 +783,9 @@ define_maps! { <'tcx>
     [] def_span: DefSpan(DefId) -> Span,
     [] stability: Stability(DefId) -> Option<attr::Stability>,
     [] deprecation: Deprecation(DefId) -> Option<attr::Deprecation>,
-    [] item_body_nested_bodies: metadata_dep_node(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
-    [] const_is_rvalue_promotable_to_static: metadata_dep_node(DefId) -> bool,
-    [] is_mir_available: metadata_dep_node(DefId) -> bool,
+    [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
+    [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
+    [] is_mir_available: IsMirAvailable(DefId) -> bool,
 }
 
 fn coherent_trait_dep_node((_, def_id): (CrateNum, DefId)) -> DepNode<DefId> {
@@ -800,10 +800,6 @@ fn reachability_dep_node(_: CrateNum) -> DepNode<DefId> {
     DepNode::Reachability
 }
 
-fn metadata_dep_node(def_id: DefId) -> DepNode<DefId> {
-    DepNode::MetaData(def_id)
-}
-
 fn mir_shim_dep_node(instance: ty::InstanceDef) -> DepNode<DefId> {
     instance.dep_node()
 }

From a12a55f519baea94c049fcda6d14dcd56110f39d Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Wed, 3 May 2017 08:40:32 -0500
Subject: [PATCH 02/10] item_attrs

---
 src/librustc/dep_graph/dep_node.rs   | 2 ++
 src/librustc/middle/cstore.rs        | 2 --
 src/librustc/ty/maps.rs              | 8 ++++++++
 src/librustc/ty/mod.rs               | 2 +-
 src/librustc_metadata/cstore_impl.rs | 7 +------
 5 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 1c71079e94b..fb8678ce93e 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -157,6 +157,7 @@ pub enum DepNode<D: Clone + Debug> {
     ItemBodyNestedBodies(D),
     ConstIsRvaluePromotableToStatic(D),
     IsMirAvailable(D),
+    ItemAttrs(D),
 }
 
 impl<D: Clone + Debug> DepNode<D> {
@@ -267,6 +268,7 @@ impl<D: Clone + Debug> DepNode<D> {
             DefSpan(ref d) => op(d).map(DefSpan),
             Stability(ref d) => op(d).map(Stability),
             Deprecation(ref d) => op(d).map(Deprecation),
+            ItemAttrs(ref d) => op(d).map(ItemAttrs),
             ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
             IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index 303c5059e7c..e30b4b2818e 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -182,7 +182,6 @@ pub trait CrateStore {
     fn visibility(&self, def: DefId) -> ty::Visibility;
     fn visible_parent_map<'a>(&'a self) -> ::std::cell::Ref<'a, DefIdMap<DefId>>;
     fn item_generics_cloned(&self, def: DefId) -> ty::Generics;
-    fn item_attrs(&self, def_id: DefId) -> Rc<[ast::Attribute]>;
     fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name>;
 
     // trait info
@@ -309,7 +308,6 @@ impl CrateStore for DummyCrateStore {
     }
     fn item_generics_cloned(&self, def: DefId) -> ty::Generics
         { bug!("item_generics_cloned") }
-    fn item_attrs(&self, def_id: DefId) -> Rc<[ast::Attribute]> { bug!("item_attrs") }
     fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name> { bug!("fn_arg_names") }
 
     // trait info
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 513240a4ec3..948df617867 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -34,6 +34,7 @@ use std::ops::Deref;
 use std::rc::Rc;
 use syntax_pos::{Span, DUMMY_SP};
 use syntax::attr;
+use syntax::ast;
 use syntax::symbol::Symbol;
 
 pub trait Key: Clone + Hash + Eq + Debug {
@@ -334,6 +335,12 @@ impl<'tcx> QueryDescription for queries::deprecation<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::item_attrs<'tcx> {
+    fn describe(_: TyCtxt, _: DefId) -> String {
+        bug!("item_attrs")
+    }
+}
+
 impl<'tcx> QueryDescription for queries::item_body_nested_bodies<'tcx> {
     fn describe(tcx: TyCtxt, def_id: DefId) -> String {
         format!("nested item bodies of `{}`", tcx.item_path_str(def_id))
@@ -783,6 +790,7 @@ define_maps! { <'tcx>
     [] def_span: DefSpan(DefId) -> Span,
     [] stability: Stability(DefId) -> Option<attr::Stability>,
     [] deprecation: Deprecation(DefId) -> Option<attr::Deprecation>,
+    [] item_attrs: ItemAttrs(DefId) -> Rc<[ast::Attribute]>,
     [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
     [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
     [] is_mir_available: IsMirAvailable(DefId) -> bool,
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 55466b1f36d..3cc250f0814 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2357,7 +2357,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         if let Some(id) = self.hir.as_local_node_id(did) {
             Attributes::Borrowed(self.hir.attrs(id))
         } else {
-            Attributes::Owned(self.sess.cstore.item_attrs(did))
+            Attributes::Owned(self.item_attrs(did))
         }
     }
 
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index a1794ec2d82..c7a52922e2a 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -113,6 +113,7 @@ provide! { <'tcx> tcx, def_id, cdata
     def_span => { cdata.get_span(def_id.index, &tcx.sess) }
     stability => { cdata.get_stability(def_id.index) }
     deprecation => { cdata.get_deprecation(def_id.index) }
+    item_attrs => { cdata.get_item_attrs(def_id.index) }
     item_body_nested_bodies => {
         let map: BTreeMap<_, _> = cdata.entry(def_id.index).ast.into_iter().flat_map(|ast| {
             ast.decode(cdata).nested_bodies.decode(cdata).map(|body| (body.id(), body))
@@ -145,12 +146,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(def.krate).get_generics(def.index)
     }
 
-    fn item_attrs(&self, def_id: DefId) -> Rc<[ast::Attribute]>
-    {
-        self.dep_graph.read(DepNode::MetaData(def_id));
-        self.get_crate_data(def_id.krate).get_item_attrs(def_id.index)
-    }
-
     fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name>
     {
         // FIXME(#38501) We've skipped a `read` on the `HirBody` of

From c72a16b8e2e1febb300cab5b97fc3265a463e775 Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Wed, 3 May 2017 09:01:49 -0500
Subject: [PATCH 03/10] fn_arg_names

---
 src/librustc/dep_graph/dep_node.rs   |  2 ++
 src/librustc/middle/cstore.rs        |  2 --
 src/librustc/ty/maps.rs              |  7 +++++++
 src/librustc_metadata/cstore_impl.rs | 15 +++++----------
 src/librustdoc/clean/mod.rs          |  2 +-
 5 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index fb8678ce93e..591c128a165 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -158,6 +158,7 @@ pub enum DepNode<D: Clone + Debug> {
     ConstIsRvaluePromotableToStatic(D),
     IsMirAvailable(D),
     ItemAttrs(D),
+    FnArgNames(D),
 }
 
 impl<D: Clone + Debug> DepNode<D> {
@@ -269,6 +270,7 @@ impl<D: Clone + Debug> DepNode<D> {
             Stability(ref d) => op(d).map(Stability),
             Deprecation(ref d) => op(d).map(Deprecation),
             ItemAttrs(ref d) => op(d).map(ItemAttrs),
+            FnArgNames(ref d) => op(d).map(FnArgNames),
             ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
             IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index e30b4b2818e..00904f54061 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -182,7 +182,6 @@ pub trait CrateStore {
     fn visibility(&self, def: DefId) -> ty::Visibility;
     fn visible_parent_map<'a>(&'a self) -> ::std::cell::Ref<'a, DefIdMap<DefId>>;
     fn item_generics_cloned(&self, def: DefId) -> ty::Generics;
-    fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name>;
 
     // trait info
     fn implementations_of_trait(&self, filter: Option<DefId>) -> Vec<DefId>;
@@ -308,7 +307,6 @@ impl CrateStore for DummyCrateStore {
     }
     fn item_generics_cloned(&self, def: DefId) -> ty::Generics
         { bug!("item_generics_cloned") }
-    fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name> { bug!("fn_arg_names") }
 
     // trait info
     fn implementations_of_trait(&self, filter: Option<DefId>) -> Vec<DefId> { vec![] }
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 948df617867..43f6c94b8b0 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -341,6 +341,12 @@ impl<'tcx> QueryDescription for queries::item_attrs<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::fn_arg_names<'tcx> {
+    fn describe(_: TyCtxt, _: DefId) -> String {
+        bug!("fn_arg_names")
+    }
+}
+
 impl<'tcx> QueryDescription for queries::item_body_nested_bodies<'tcx> {
     fn describe(tcx: TyCtxt, def_id: DefId) -> String {
         format!("nested item bodies of `{}`", tcx.item_path_str(def_id))
@@ -791,6 +797,7 @@ define_maps! { <'tcx>
     [] stability: Stability(DefId) -> Option<attr::Stability>,
     [] deprecation: Deprecation(DefId) -> Option<attr::Deprecation>,
     [] item_attrs: ItemAttrs(DefId) -> Rc<[ast::Attribute]>,
+    [] fn_arg_names: FnArgNames(DefId) -> Vec<ast::Name>,
     [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
     [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
     [] is_mir_available: IsMirAvailable(DefId) -> bool,
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index c7a52922e2a..325ba14da9c 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -114,6 +114,11 @@ provide! { <'tcx> tcx, def_id, cdata
     stability => { cdata.get_stability(def_id.index) }
     deprecation => { cdata.get_deprecation(def_id.index) }
     item_attrs => { cdata.get_item_attrs(def_id.index) }
+    // FIXME(#38501) We've skipped a `read` on the `HirBody` of
+    // a `fn` when encoding, so the dep-tracking wouldn't work.
+    // This is only used by rustdoc anyway, which shouldn't have
+    // incremental recompilation ever enabled.
+    fn_arg_names => { cdata.get_fn_arg_names(def_id.index) }
     item_body_nested_bodies => {
         let map: BTreeMap<_, _> = cdata.entry(def_id.index).ast.into_iter().flat_map(|ast| {
             ast.decode(cdata).nested_bodies.decode(cdata).map(|body| (body.id(), body))
@@ -146,16 +151,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(def.krate).get_generics(def.index)
     }
 
-    fn fn_arg_names(&self, did: DefId) -> Vec<ast::Name>
-    {
-        // FIXME(#38501) We've skipped a `read` on the `HirBody` of
-        // a `fn` when encoding, so the dep-tracking wouldn't work.
-        // This is only used by rustdoc anyway, which shouldn't have
-        // incremental recompilation ever enabled.
-        assert!(!self.dep_graph.is_fully_enabled());
-        self.get_crate_data(did.krate).get_fn_arg_names(did.index)
-    }
-
     fn implementations_of_trait(&self, filter: Option<DefId>) -> Vec<DefId>
     {
         if let Some(def_id) = filter {
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 0a748487244..78b96e1833b 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1179,7 +1179,7 @@ impl<'a, 'tcx> Clean<FnDecl> for (DefId, ty::PolyFnSig<'tcx>) {
         let mut names = if cx.tcx.hir.as_local_node_id(did).is_some() {
             vec![].into_iter()
         } else {
-            cx.tcx.sess.cstore.fn_arg_names(did).into_iter()
+            cx.tcx.fn_arg_names(did).into_iter()
         }.peekable();
         FnDecl {
             output: Return(sig.skip_binder().output().clean(cx)),

From aa5a5320466d4a6ac7125cb01956307e63d9918b Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Thu, 4 May 2017 08:27:48 -0500
Subject: [PATCH 04/10] trait_of_item

---
 src/librustc/dep_graph/dep_node.rs   |  2 ++
 src/librustc/middle/cstore.rs        |  2 --
 src/librustc/ty/maps.rs              |  7 ++++++
 src/librustc/ty/mod.rs               | 34 +++++++++++++++-------------
 src/librustc_const_eval/eval.rs      |  2 +-
 src/librustc_metadata/cstore_impl.rs |  6 +----
 6 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 591c128a165..0e462b95d82 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -156,6 +156,7 @@ pub enum DepNode<D: Clone + Debug> {
     Deprecation(D),
     ItemBodyNestedBodies(D),
     ConstIsRvaluePromotableToStatic(D),
+    TraitOfItem(D),
     IsMirAvailable(D),
     ItemAttrs(D),
     FnArgNames(D),
@@ -271,6 +272,7 @@ impl<D: Clone + Debug> DepNode<D> {
             Deprecation(ref d) => op(d).map(Deprecation),
             ItemAttrs(ref d) => op(d).map(ItemAttrs),
             FnArgNames(ref d) => op(d).map(FnArgNames),
+            TraitOfItem(ref d) => op(d).map(TraitOfItem),
             ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
             IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index 00904f54061..11a2dfc6685 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -191,7 +191,6 @@ pub trait CrateStore {
     fn impl_parent(&self, impl_def_id: DefId) -> Option<DefId>;
 
     // trait/impl-item info
-    fn trait_of_item(&self, def_id: DefId) -> Option<DefId>;
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem;
 
     // flags
@@ -316,7 +315,6 @@ impl CrateStore for DummyCrateStore {
     fn impl_parent(&self, def: DefId) -> Option<DefId> { bug!("impl_parent") }
 
     // trait/impl-item info
-    fn trait_of_item(&self, def_id: DefId) -> Option<DefId> { bug!("trait_of_item") }
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem
         { bug!("associated_item_cloned") }
 
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 43f6c94b8b0..5d1b16c3d2e 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -347,6 +347,12 @@ impl<'tcx> QueryDescription for queries::fn_arg_names<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::trait_of_item<'tcx> {
+    fn describe(_: TyCtxt, _: DefId) -> String {
+        bug!("trait_of_item")
+    }
+}
+
 impl<'tcx> QueryDescription for queries::item_body_nested_bodies<'tcx> {
     fn describe(tcx: TyCtxt, def_id: DefId) -> String {
         format!("nested item bodies of `{}`", tcx.item_path_str(def_id))
@@ -798,6 +804,7 @@ define_maps! { <'tcx>
     [] deprecation: Deprecation(DefId) -> Option<attr::Deprecation>,
     [] item_attrs: ItemAttrs(DefId) -> Rc<[ast::Attribute]>,
     [] fn_arg_names: FnArgNames(DefId) -> Vec<ast::Name>,
+    [] trait_of_item: TraitOfItem(DefId) -> Option<DefId>,
     [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
     [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
     [] is_mir_available: IsMirAvailable(DefId) -> bool,
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 3cc250f0814..00f81c9dcf7 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2430,22 +2430,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
-    /// If the given def ID describes an item belonging to a trait,
-    /// return the ID of the trait that the trait item belongs to.
-    /// Otherwise, return `None`.
-    pub fn trait_of_item(self, def_id: DefId) -> Option<DefId> {
-        if def_id.krate != LOCAL_CRATE {
-            return self.sess.cstore.trait_of_item(def_id);
-        }
-        self.opt_associated_item(def_id)
-            .and_then(|associated_item| {
-                match associated_item.container {
-                    TraitContainer(def_id) => Some(def_id),
-                    ImplContainer(_) => None
-                }
-            })
-    }
-
     /// Construct a parameter environment suitable for static contexts or other contexts where there
     /// are no free type/lifetime parameters in scope.
     pub fn empty_parameter_environment(self) -> ParameterEnvironment<'tcx> {
@@ -2693,6 +2677,23 @@ fn def_span<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Span {
     tcx.hir.span_if_local(def_id).unwrap()
 }
 
+/// If the given def ID describes an item belonging to a trait,
+/// return the ID of the trait that the trait item belongs to.
+/// Otherwise, return `None`.
+fn trait_of_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Option<DefId> {
+    if def_id.krate != LOCAL_CRATE {
+        return None
+    }
+    tcx.opt_associated_item(def_id)
+        .and_then(|associated_item| {
+            match associated_item.container {
+                TraitContainer(def_id) => Some(def_id),
+                ImplContainer(_) => None
+            }
+        })
+}
+
+
 pub fn provide(providers: &mut ty::maps::Providers) {
     *providers = ty::maps::Providers {
         associated_item,
@@ -2700,6 +2701,7 @@ pub fn provide(providers: &mut ty::maps::Providers) {
         adt_sized_constraint,
         adt_dtorck_constraint,
         def_span,
+        trait_of_item,
         ..*providers
     };
 }
diff --git a/src/librustc_const_eval/eval.rs b/src/librustc_const_eval/eval.rs
index 8b1aa070880..e79f23aee11 100644
--- a/src/librustc_const_eval/eval.rs
+++ b/src/librustc_const_eval/eval.rs
@@ -74,7 +74,7 @@ pub fn lookup_const_by_id<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 // constants, we only try to find the expression for a
                 // trait-associated const if the caller gives us the
                 // substitutions for the reference to it.
-                if tcx.sess.cstore.trait_of_item(def_id).is_some() {
+                if tcx.trait_of_item(def_id).is_some() {
                     resolve_trait_associated_const(tcx, def_id, substs)
                 } else {
                     Some((def_id, substs))
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index 325ba14da9c..b07dd1ec7b0 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -119,6 +119,7 @@ provide! { <'tcx> tcx, def_id, cdata
     // This is only used by rustdoc anyway, which shouldn't have
     // incremental recompilation ever enabled.
     fn_arg_names => { cdata.get_fn_arg_names(def_id.index) }
+    trait_of_item => { cdata.get_trait_of_item(def_id.index) }
     item_body_nested_bodies => {
         let map: BTreeMap<_, _> = cdata.entry(def_id.index).ast.into_iter().flat_map(|ast| {
             ast.decode(cdata).nested_bodies.decode(cdata).map(|body| (body.id(), body))
@@ -174,11 +175,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(impl_def.krate).get_parent_impl(impl_def.index)
     }
 
-    fn trait_of_item(&self, def_id: DefId) -> Option<DefId> {
-        self.dep_graph.read(DepNode::MetaData(def_id));
-        self.get_crate_data(def_id.krate).get_trait_of_item(def_id.index)
-    }
-
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem
     {
         self.dep_graph.read(DepNode::MetaData(def));

From 03fe10d91d3361144ab5c8a142daf63bc0ff143e Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Thu, 4 May 2017 09:37:34 -0500
Subject: [PATCH 05/10] impl_parent

---
 src/librustc/dep_graph/dep_node.rs   | 2 ++
 src/librustc/middle/cstore.rs        | 2 --
 src/librustc/ty/maps.rs              | 7 +++++++
 src/librustc/ty/mod.rs               | 2 +-
 src/librustc_metadata/cstore_impl.rs | 6 +-----
 5 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index 0e462b95d82..de1531bbd54 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -156,6 +156,7 @@ pub enum DepNode<D: Clone + Debug> {
     Deprecation(D),
     ItemBodyNestedBodies(D),
     ConstIsRvaluePromotableToStatic(D),
+    ImplParent(D),
     TraitOfItem(D),
     IsMirAvailable(D),
     ItemAttrs(D),
@@ -272,6 +273,7 @@ impl<D: Clone + Debug> DepNode<D> {
             Deprecation(ref d) => op(d).map(Deprecation),
             ItemAttrs(ref d) => op(d).map(ItemAttrs),
             FnArgNames(ref d) => op(d).map(FnArgNames),
+            ImplParent(ref d) => op(d).map(ImplParent),
             TraitOfItem(ref d) => op(d).map(TraitOfItem),
             ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index 11a2dfc6685..e50072043d5 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -188,7 +188,6 @@ pub trait CrateStore {
 
     // impl info
     fn impl_defaultness(&self, def: DefId) -> hir::Defaultness;
-    fn impl_parent(&self, impl_def_id: DefId) -> Option<DefId>;
 
     // trait/impl-item info
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem;
@@ -312,7 +311,6 @@ impl CrateStore for DummyCrateStore {
 
     // impl info
     fn impl_defaultness(&self, def: DefId) -> hir::Defaultness { bug!("impl_defaultness") }
-    fn impl_parent(&self, def: DefId) -> Option<DefId> { bug!("impl_parent") }
 
     // trait/impl-item info
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 5d1b16c3d2e..1dfd7bc9760 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -347,6 +347,12 @@ impl<'tcx> QueryDescription for queries::fn_arg_names<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::impl_parent<'tcx> {
+    fn describe(_: TyCtxt, _: DefId) -> String {
+        bug!("impl_parent")
+    }
+}
+
 impl<'tcx> QueryDescription for queries::trait_of_item<'tcx> {
     fn describe(_: TyCtxt, _: DefId) -> String {
         bug!("trait_of_item")
@@ -804,6 +810,7 @@ define_maps! { <'tcx>
     [] deprecation: Deprecation(DefId) -> Option<attr::Deprecation>,
     [] item_attrs: ItemAttrs(DefId) -> Rc<[ast::Attribute]>,
     [] fn_arg_names: FnArgNames(DefId) -> Vec<ast::Name>,
+    [] impl_parent: ImplParent(DefId) -> Option<DefId>,
     [] trait_of_item: TraitOfItem(DefId) -> Option<DefId>,
     [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
     [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 00f81c9dcf7..1c3e74d4fb9 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2393,7 +2393,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             let trait_ref = self.impl_trait_ref(impl_def_id).unwrap();
 
             // Record the trait->implementation mapping.
-            let parent = self.sess.cstore.impl_parent(impl_def_id).unwrap_or(trait_id);
+            let parent = self.impl_parent(impl_def_id).unwrap_or(trait_id);
             def.record_remote_impl(self, impl_def_id, trait_ref, parent);
         }
 
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index b07dd1ec7b0..b54db55c0e1 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -119,6 +119,7 @@ provide! { <'tcx> tcx, def_id, cdata
     // This is only used by rustdoc anyway, which shouldn't have
     // incremental recompilation ever enabled.
     fn_arg_names => { cdata.get_fn_arg_names(def_id.index) }
+    impl_parent => { cdata.get_parent_impl(def_id.index) }
     trait_of_item => { cdata.get_trait_of_item(def_id.index) }
     item_body_nested_bodies => {
         let map: BTreeMap<_, _> = cdata.entry(def_id.index).ast.into_iter().flat_map(|ast| {
@@ -170,11 +171,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(def.krate).get_impl_defaultness(def.index)
     }
 
-    fn impl_parent(&self, impl_def: DefId) -> Option<DefId> {
-        self.dep_graph.read(DepNode::MetaData(impl_def));
-        self.get_crate_data(impl_def.krate).get_parent_impl(impl_def.index)
-    }
-
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem
     {
         self.dep_graph.read(DepNode::MetaData(def));

From 5b71d769ffe751399b538fb0fdb51ec88345061b Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Thu, 4 May 2017 12:45:56 -0500
Subject: [PATCH 06/10] moved metadata provider impls to decoder

---
 src/librustc_metadata/cstore_impl.rs | 18 +++---------------
 src/librustc_metadata/decoder.rs     | 23 ++++++++++++++++++++---
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index b54db55c0e1..a0c887e95d6 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -41,8 +41,6 @@ use rustc::hir::svh::Svh;
 use rustc_back::target::Target;
 use rustc::hir;
 
-use std::collections::BTreeMap;
-
 macro_rules! provide {
     (<$lt:tt> $tcx:ident, $def_id:ident, $cdata:ident $($name:ident => $compute:block)*) => {
         pub fn provide<$lt>(providers: &mut Providers<$lt>) {
@@ -121,21 +119,11 @@ provide! { <'tcx> tcx, def_id, cdata
     fn_arg_names => { cdata.get_fn_arg_names(def_id.index) }
     impl_parent => { cdata.get_parent_impl(def_id.index) }
     trait_of_item => { cdata.get_trait_of_item(def_id.index) }
-    item_body_nested_bodies => {
-        let map: BTreeMap<_, _> = cdata.entry(def_id.index).ast.into_iter().flat_map(|ast| {
-            ast.decode(cdata).nested_bodies.decode(cdata).map(|body| (body.id(), body))
-        }).collect();
-
-        Rc::new(map)
-    }
+    item_body_nested_bodies => { Rc::new(cdata.item_body_nested_bodies(def_id.index)) }
     const_is_rvalue_promotable_to_static => {
-        cdata.entry(def_id.index).ast.expect("const item missing `ast`")
-            .decode(cdata).rvalue_promotable_to_static
-    }
-    is_mir_available => {
-        !cdata.is_proc_macro(def_id.index) &&
-        cdata.maybe_entry(def_id.index).and_then(|item| item.decode(cdata).mir).is_some()
+        cdata.const_is_rvalue_promotable_to_static(def_id.index)
     }
+    is_mir_available => { cdata.is_item_mir_available(def_id.index) }
 }
 
 impl CrateStore for cstore::CStore {
diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index ae755adcf5f..b89b5181e7b 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -29,6 +29,7 @@ use rustc::mir::Mir;
 
 use std::borrow::Cow;
 use std::cell::Ref;
+use std::collections::BTreeMap;
 use std::io;
 use std::mem;
 use std::rc::Rc;
@@ -448,16 +449,16 @@ impl<'tcx> EntryKind<'tcx> {
 }
 
 impl<'a, 'tcx> CrateMetadata {
-    pub fn is_proc_macro(&self, id: DefIndex) -> bool {
+    fn is_proc_macro(&self, id: DefIndex) -> bool {
         self.proc_macros.is_some() && id != CRATE_DEF_INDEX
     }
 
-    pub fn maybe_entry(&self, item_id: DefIndex) -> Option<Lazy<Entry<'tcx>>> {
+    fn maybe_entry(&self, item_id: DefIndex) -> Option<Lazy<Entry<'tcx>>> {
         assert!(!self.is_proc_macro(item_id));
         self.root.index.lookup(self.blob.raw_bytes(), item_id)
     }
 
-    pub fn entry(&self, item_id: DefIndex) -> Entry<'tcx> {
+    fn entry(&self, item_id: DefIndex) -> Entry<'tcx> {
         match self.maybe_entry(item_id) {
             None => {
                 bug!("entry: id not found: {:?} in crate {:?} with number {}",
@@ -779,6 +780,22 @@ impl<'a, 'tcx> CrateMetadata {
         tcx.alloc_tables(ast.tables.decode((self, tcx)))
     }
 
+    pub fn item_body_nested_bodies(&self, id: DefIndex) -> BTreeMap<hir::BodyId, hir::Body> {
+        self.entry(id).ast.into_iter().flat_map(|ast| {
+            ast.decode(self).nested_bodies.decode(self).map(|body| (body.id(), body))
+        }).collect()
+    }
+
+    pub fn const_is_rvalue_promotable_to_static(&self, id: DefIndex) -> bool {
+        self.entry(id).ast.expect("const item missing `ast`")
+            .decode(self).rvalue_promotable_to_static
+    }
+
+    pub fn is_item_mir_available(&self, id: DefIndex) -> bool {
+        !self.is_proc_macro(id) &&
+        self.maybe_entry(id).and_then(|item| item.decode(self).mir).is_some()
+    }
+
     pub fn maybe_get_optimized_mir(&self,
                                    tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                    id: DefIndex)

From 5a7946df703f2d9149adc0ca5c7e0b116e82a98d Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Fri, 5 May 2017 08:15:08 -0500
Subject: [PATCH 07/10] is_foreign_item

---
 src/librustc/middle/cstore.rs           | 2 --
 src/librustc/middle/effect.rs           | 2 +-
 src/librustc_metadata/cstore_impl.rs    | 4 ----
 src/librustc_trans/back/symbol_names.rs | 2 +-
 src/librustc_trans/collector.rs         | 2 +-
 src/librustc_trans/consts.rs            | 2 +-
 6 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index e50072043d5..d9ce40a0d7d 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -195,7 +195,6 @@ pub trait CrateStore {
     // flags
     fn is_const_fn(&self, did: DefId) -> bool;
     fn is_default_impl(&self, impl_did: DefId) -> bool;
-    fn is_foreign_item(&self, did: DefId) -> bool;
     fn is_dllimport_foreign_item(&self, def: DefId) -> bool;
     fn is_statically_included_foreign_item(&self, def_id: DefId) -> bool;
     fn is_exported_symbol(&self, def_id: DefId) -> bool;
@@ -319,7 +318,6 @@ impl CrateStore for DummyCrateStore {
     // flags
     fn is_const_fn(&self, did: DefId) -> bool { bug!("is_const_fn") }
     fn is_default_impl(&self, impl_did: DefId) -> bool { bug!("is_default_impl") }
-    fn is_foreign_item(&self, did: DefId) -> bool { bug!("is_foreign_item") }
     fn is_dllimport_foreign_item(&self, id: DefId) -> bool { false }
     fn is_statically_included_foreign_item(&self, def_id: DefId) -> bool { false }
     fn is_exported_symbol(&self, def_id: DefId) -> bool { false }
diff --git a/src/librustc/middle/effect.rs b/src/librustc/middle/effect.rs
index d2b8ed8c297..4bbf37b21ed 100644
--- a/src/librustc/middle/effect.rs
+++ b/src/librustc/middle/effect.rs
@@ -205,7 +205,7 @@ impl<'a, 'tcx> Visitor<'tcx> for EffectCheckVisitor<'a, 'tcx> {
                     } else if match self.tcx.hir.get_if_local(def_id) {
                         Some(hir::map::NodeForeignItem(..)) => true,
                         Some(..) => false,
-                        None => self.tcx.sess.cstore.is_foreign_item(def_id),
+                        None => self.tcx.is_foreign_item(def_id),
                     } {
                         self.require_unsafe_ext(expr.id, expr.span, "use of extern static", true);
                     }
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index a0c887e95d6..7bd431ff446 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -176,10 +176,6 @@ impl CrateStore for cstore::CStore {
         self.get_crate_data(impl_did.krate).is_default_impl(impl_did.index)
     }
 
-    fn is_foreign_item(&self, did: DefId) -> bool {
-        self.get_crate_data(did.krate).is_foreign_item(did.index)
-    }
-
     fn is_statically_included_foreign_item(&self, def_id: DefId) -> bool
     {
         self.do_is_statically_included_foreign_item(def_id)
diff --git a/src/librustc_trans/back/symbol_names.rs b/src/librustc_trans/back/symbol_names.rs
index aef9140ba45..1aed2932948 100644
--- a/src/librustc_trans/back/symbol_names.rs
+++ b/src/librustc_trans/back/symbol_names.rs
@@ -223,7 +223,7 @@ fn compute_symbol_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, instance: Instance
             _ => false
         }
     } else {
-        tcx.sess.cstore.is_foreign_item(def_id)
+        tcx.is_foreign_item(def_id)
     };
 
     if let Some(name) = weak_lang_items::link_name(&attrs) {
diff --git a/src/librustc_trans/collector.rs b/src/librustc_trans/collector.rs
index 6d7d95f5487..f0be0941ccf 100644
--- a/src/librustc_trans/collector.rs
+++ b/src/librustc_trans/collector.rs
@@ -653,7 +653,7 @@ fn should_trans_locally<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, instance: &Instan
         Some(_) => true,
         None => {
             if tcx.sess.cstore.is_exported_symbol(def_id) ||
-                tcx.sess.cstore.is_foreign_item(def_id)
+                tcx.is_foreign_item(def_id)
             {
                 // We can link to the item in question, no instance needed
                 // in this crate
diff --git a/src/librustc_trans/consts.rs b/src/librustc_trans/consts.rs
index 6afb340107d..eac0a062567 100644
--- a/src/librustc_trans/consts.rs
+++ b/src/librustc_trans/consts.rs
@@ -186,7 +186,7 @@ pub fn get_static(ccx: &CrateContext, def_id: DefId) -> ValueRef {
                 llvm::set_thread_local(g, true);
             }
         }
-        if ccx.use_dll_storage_attrs() && !ccx.sess().cstore.is_foreign_item(def_id) {
+        if ccx.use_dll_storage_attrs() && !ccx.tcx().is_foreign_item(def_id) {
             // This item is external but not foreign, i.e. it originates from an external Rust
             // crate. Since we don't know whether this crate will be linked dynamically or
             // statically in the final application, we always mark such symbols as 'dllimport'.

From d561d4c9eb808cbca28fd641934825fdf96fb762 Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Fri, 5 May 2017 14:40:26 -0500
Subject: [PATCH 08/10] propper trait of item impl

---
 src/librustc/ty/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 1c3e74d4fb9..9f43ed9bf5b 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2682,7 +2682,7 @@ fn def_span<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Span {
 /// Otherwise, return `None`.
 fn trait_of_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Option<DefId> {
     if def_id.krate != LOCAL_CRATE {
-        return None
+        return tcx.trait_of_item(def_id)
     }
     tcx.opt_associated_item(def_id)
         .and_then(|associated_item| {

From 1f532bfed5e0a80bf145f5db504601dc037367a1 Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Sun, 7 May 2017 21:05:31 -0500
Subject: [PATCH 09/10] is_exported_symbol

---
 src/librustc/dep_graph/dep_node.rs   | 2 ++
 src/librustc/middle/cstore.rs        | 2 --
 src/librustc/ty/maps.rs              | 7 +++++++
 src/librustc_metadata/cstore_impl.rs | 5 +----
 src/librustc_trans/collector.rs      | 2 +-
 5 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index de1531bbd54..712ada4ec65 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -158,6 +158,7 @@ pub enum DepNode<D: Clone + Debug> {
     ConstIsRvaluePromotableToStatic(D),
     ImplParent(D),
     TraitOfItem(D),
+    IsExportedSymbol(D),
     IsMirAvailable(D),
     ItemAttrs(D),
     FnArgNames(D),
@@ -275,6 +276,7 @@ impl<D: Clone + Debug> DepNode<D> {
             FnArgNames(ref d) => op(d).map(FnArgNames),
             ImplParent(ref d) => op(d).map(ImplParent),
             TraitOfItem(ref d) => op(d).map(TraitOfItem),
+            IsExportedSymbol(ref d) => op(d).map(IsExportedSymbol),
             ItemBodyNestedBodies(ref d) => op(d).map(ItemBodyNestedBodies),
             ConstIsRvaluePromotableToStatic(ref d) => op(d).map(ConstIsRvaluePromotableToStatic),
             IsMirAvailable(ref d) => op(d).map(IsMirAvailable),
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index d9ce40a0d7d..6f0a990ca41 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -197,7 +197,6 @@ pub trait CrateStore {
     fn is_default_impl(&self, impl_did: DefId) -> bool;
     fn is_dllimport_foreign_item(&self, def: DefId) -> bool;
     fn is_statically_included_foreign_item(&self, def_id: DefId) -> bool;
-    fn is_exported_symbol(&self, def_id: DefId) -> bool;
 
     // crate metadata
     fn dylib_dependency_formats(&self, cnum: CrateNum)
@@ -320,7 +319,6 @@ impl CrateStore for DummyCrateStore {
     fn is_default_impl(&self, impl_did: DefId) -> bool { bug!("is_default_impl") }
     fn is_dllimport_foreign_item(&self, id: DefId) -> bool { false }
     fn is_statically_included_foreign_item(&self, def_id: DefId) -> bool { false }
-    fn is_exported_symbol(&self, def_id: DefId) -> bool { false }
 
     // crate metadata
     fn dylib_dependency_formats(&self, cnum: CrateNum)
diff --git a/src/librustc/ty/maps.rs b/src/librustc/ty/maps.rs
index 1dfd7bc9760..80783a547bf 100644
--- a/src/librustc/ty/maps.rs
+++ b/src/librustc/ty/maps.rs
@@ -341,6 +341,12 @@ impl<'tcx> QueryDescription for queries::item_attrs<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::is_exported_symbol<'tcx> {
+    fn describe(_: TyCtxt, _: DefId) -> String {
+        bug!("is_exported_symbol")
+    }
+}
+
 impl<'tcx> QueryDescription for queries::fn_arg_names<'tcx> {
     fn describe(_: TyCtxt, _: DefId) -> String {
         bug!("fn_arg_names")
@@ -812,6 +818,7 @@ define_maps! { <'tcx>
     [] fn_arg_names: FnArgNames(DefId) -> Vec<ast::Name>,
     [] impl_parent: ImplParent(DefId) -> Option<DefId>,
     [] trait_of_item: TraitOfItem(DefId) -> Option<DefId>,
+    [] is_exported_symbol: IsExportedSymbol(DefId) -> bool,
     [] item_body_nested_bodies: ItemBodyNestedBodies(DefId) -> Rc<BTreeMap<hir::BodyId, hir::Body>>,
     [] const_is_rvalue_promotable_to_static: ConstIsRvaluePromotableToStatic(DefId) -> bool,
     [] is_mir_available: IsMirAvailable(DefId) -> bool,
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index 7bd431ff446..d29fa8f0814 100644
--- a/src/librustc_metadata/cstore_impl.rs
+++ b/src/librustc_metadata/cstore_impl.rs
@@ -119,6 +119,7 @@ provide! { <'tcx> tcx, def_id, cdata
     fn_arg_names => { cdata.get_fn_arg_names(def_id.index) }
     impl_parent => { cdata.get_parent_impl(def_id.index) }
     trait_of_item => { cdata.get_trait_of_item(def_id.index) }
+    is_exported_symbol => { cdata.exported_symbols.contains(&def_id.index) }
     item_body_nested_bodies => { Rc::new(cdata.item_body_nested_bodies(def_id.index)) }
     const_is_rvalue_promotable_to_static => {
         cdata.const_is_rvalue_promotable_to_static(def_id.index)
@@ -181,10 +182,6 @@ impl CrateStore for cstore::CStore {
         self.do_is_statically_included_foreign_item(def_id)
     }
 
-    fn is_exported_symbol(&self, def_id: DefId) -> bool {
-        self.get_crate_data(def_id.krate).exported_symbols.contains(&def_id.index)
-    }
-
     fn is_dllimport_foreign_item(&self, def_id: DefId) -> bool {
         if def_id.krate == LOCAL_CRATE {
             self.dllimport_foreign_items.borrow().contains(&def_id.index)
diff --git a/src/librustc_trans/collector.rs b/src/librustc_trans/collector.rs
index f0be0941ccf..5f8b79a994a 100644
--- a/src/librustc_trans/collector.rs
+++ b/src/librustc_trans/collector.rs
@@ -652,7 +652,7 @@ fn should_trans_locally<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, instance: &Instan
         }
         Some(_) => true,
         None => {
-            if tcx.sess.cstore.is_exported_symbol(def_id) ||
+            if tcx.is_exported_symbol(def_id) ||
                 tcx.is_foreign_item(def_id)
             {
                 // We can link to the item in question, no instance needed

From dfb740f83ca1d6f2056f5cf8de1adbe81b973438 Mon Sep 17 00:00:00 2001
From: achernyak <artemchernyak@gmail.com>
Date: Mon, 8 May 2017 14:30:30 -0500
Subject: [PATCH 10/10] removed unnecessary if

---
 src/librustc/ty/mod.rs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 9f43ed9bf5b..a065dd6a592 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2681,9 +2681,6 @@ fn def_span<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Span {
 /// return the ID of the trait that the trait item belongs to.
 /// Otherwise, return `None`.
 fn trait_of_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Option<DefId> {
-    if def_id.krate != LOCAL_CRATE {
-        return tcx.trait_of_item(def_id)
-    }
     tcx.opt_associated_item(def_id)
         .and_then(|associated_item| {
             match associated_item.container {