Auto merge of #41905 - frewsxcv:rollup, r=frewsxcv

Rollup of 5 pull requests

- Successful merges: #41192, #41724, #41873, #41877, #41889
- Failed merges:

23 files changed, 296 insertions, 128 deletions

diff --git a/src/doc/unstable-book/src/SUMMARY.md b/src/doc/unstable-book/src/SUMMARY.md
index 3d9e7c7fd86..8f26e4d36cd 100644
--- a/src/doc/unstable-book/src/SUMMARY.md
+++ b/src/doc/unstable-book/src/SUMMARY.md
@@ -178,7 +178,7 @@
     - [peek](library-features/peek.md)
     - [placement_in](library-features/placement-in.md)
     - [placement_new_protocol](library-features/placement-new-protocol.md)
-    - [print](library-features/print.md)
+    - [print_internals](library-features/print-internals.md)
     - [proc_macro_internals](library-features/proc-macro-internals.md)
     - [process_try_wait](library-features/process-try-wait.md)
     - [question_mark_carrier](library-features/question-mark-carrier.md)
diff --git a/src/doc/unstable-book/src/library-features/print.md b/src/doc/unstable-book/src/library-features/print-internals.md
index dc25cb237e3..a68557872af 100644
--- a/src/doc/unstable-book/src/library-features/print.md
+++ b/src/doc/unstable-book/src/library-features/print-internals.md
@@ -1,4 +1,4 @@
-# `print`
+# `print_internals`
 
 This feature is internal to the Rust compiler and is not intended for general use.
 
diff --git a/src/librustc/dep_graph/dep_node.rs b/src/librustc/dep_graph/dep_node.rs
index af425a95fb1..25fc5b7a4f6 100644
--- a/src/librustc/dep_graph/dep_node.rs
+++ b/src/librustc/dep_graph/dep_node.rs
@@ -159,6 +159,14 @@ pub enum DepNode<D: Clone + Debug> {
     DefSpan(D),
     Stability(D),
     Deprecation(D),
+    ItemBodyNestedBodies(D),
+    ConstIsRvaluePromotableToStatic(D),
+    ImplParent(D),
+    TraitOfItem(D),
+    IsExportedSymbol(D),
+    IsMirAvailable(D),
+    ItemAttrs(D),
+    FnArgNames(D),
     FileMap(D, Arc<String>),
 }
 
@@ -273,6 +281,14 @@ 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),
+            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),
             GlobalMetaData(ref d, kind) => op(d).map(|d| GlobalMetaData(d, kind)),
             FileMap(ref d, ref file_name) => op(d).map(|d| FileMap(d, file_name.clone())),
         }
diff --git a/src/librustc/middle/cstore.rs b/src/librustc/middle/cstore.rs
index 16b3fcd2f8c..da899a9130c 100644
--- a/src/librustc/middle/cstore.rs
+++ b/src/librustc/middle/cstore.rs
@@ -210,27 +210,21 @@ 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
     fn implementations_of_trait(&self, filter: Option<DefId>) -> Vec<DefId>;
 
     // 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 trait_of_item(&self, def_id: DefId) -> Option<DefId>;
     fn associated_item_cloned(&self, def: DefId) -> ty::AssociatedItem;
 
     // 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;
 
     // crate metadata
     fn dylib_dependency_formats(&self, cnum: CrateNum)
@@ -337,28 +331,22 @@ 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
     fn implementations_of_trait(&self, filter: Option<DefId>) -> Vec<DefId> { vec![] }
 
     // 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 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") }
 
     // 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 }
 
     // crate metadata
     fn dylib_dependency_formats(&self, cnum: CrateNum)
diff --git a/src/librustc/middle/effect.rs b/src/librustc/middle/effect.rs
index e03948db368..5360a86560d 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/ty/maps.rs b/src/librustc/ty/maps.rs
index 82a4c1e1e62..3b5dc2ae164 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 {
@@ -340,6 +341,36 @@ 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::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")
+    }
+}
+
+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")
+    }
+}
+
 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))
@@ -781,9 +812,14 @@ 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_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>,
+    [] 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,
 }
 
 fn coherent_trait_dep_node((_, def_id): (CrateNum, DefId)) -> DepNode<DefId> {
@@ -798,10 +834,6 @@ 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()
 }
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 99a5f6325ac..51cdba56cf1 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2360,7 +2360,7 @@ 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))
         }
     }
 
@@ -2396,7 +2396,7 @@ 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);
         }
 
@@ -2433,22 +2433,6 @@ 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> {
@@ -2688,6 +2672,20 @@ 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> {
+    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,
@@ -2695,6 +2693,7 @@ 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_incremental/persist/hash.rs b/src/librustc_incremental/persist/hash.rs
index 5bc442deafa..2f727a80f01 100644
--- a/src/librustc_incremental/persist/hash.rs
+++ b/src/librustc_incremental/persist/hash.rs
@@ -79,7 +79,11 @@ impl<'a, 'tcx> HashContext<'a, 'tcx> {
 
             DepNode::FileMap(def_id, ref name) => {
                 if def_id.is_local() {
-                    Some(self.incremental_hashes_map[dep_node])
+                    // We will have been able to retrace the DefId (which is
+                    // always the local CRATE_DEF_INDEX), but the file with the
+                    // given name might have been removed, so we use get() in
+                    // order to allow for that case.
+                    self.incremental_hashes_map.get(dep_node).map(|x| *x)
                 } else {
                     Some(self.metadata_hash(DepNode::FileMap(def_id, name.clone()),
                                             def_id.krate,
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 715a769158b..3b6516af35a 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -718,7 +718,6 @@ fn fl_lit_check_expr(cx: &EarlyContext, expr: &ast::Expr) {
                     cx.span_lint(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN,
                                  l.span,
                                  "floating-point literals cannot be used in patterns");
-                    error!("span mc spanspam");
                     },
                 _ => (),
             }
diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs
index 6fa6a868605..f3fb427fed6 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>) {
@@ -113,21 +111,23 @@ 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_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_attrs => { cdata.get_item_attrs(def_id.index, &tcx.dep_graph) }
+    // 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) }
+    impl_parent => { cdata.get_parent_impl(def_id.index) }
+    trait_of_item => { cdata.get_trait_of_item(def_id.index) }
+    is_exported_symbol => {
+        let dep_node = cdata.metadata_dep_node(GlobalMetaDataKind::ExportedSymbols);
+        cdata.exported_symbols.get(&tcx.dep_graph, dep_node).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.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 {
@@ -145,22 +145,6 @@ 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.get_crate_data(def_id.krate)
-            .get_item_attrs(def_id.index, &self.dep_graph)
-    }
-
-    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 {
@@ -179,16 +163,6 @@ 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 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));
@@ -206,23 +180,11 @@ 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)
     }
 
-    fn is_exported_symbol(&self, def_id: DefId) -> bool {
-        let data = self.get_crate_data(def_id.krate);
-        let dep_node = data.metadata_dep_node(GlobalMetaDataKind::ExportedSymbols);
-        data.exported_symbols
-            .get(&self.dep_graph, dep_node)
-            .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_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index 820b5a68bcc..ea845f722c3 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -30,6 +30,7 @@ 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;
@@ -453,16 +454,16 @@ 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 {}",
@@ -789,6 +790,22 @@ 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)
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..5f8b79a994a 100644
--- a/src/librustc_trans/collector.rs
+++ b/src/librustc_trans/collector.rs
@@ -652,8 +652,8 @@ 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)
+            if tcx.is_exported_symbol(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'.
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 24d056035ce..2dde6d9d4ee 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1180,7 +1180,7 @@ 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)),
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index e2832873e2e..c872a8e5261 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -287,9 +287,11 @@ pub use self::error::{Result, Error, ErrorKind};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::util::{copy, sink, Sink, empty, Empty, repeat, Repeat};
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use self::stdio::{stdin, stdout, stderr, _print, Stdin, Stdout, Stderr};
+pub use self::stdio::{stdin, stdout, stderr, Stdin, Stdout, Stderr};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::stdio::{StdoutLock, StderrLock, StdinLock};
+#[unstable(feature = "print_internals", issue = "0")]
+pub use self::stdio::{_print, _eprint};
 #[unstable(feature = "libstd_io_internals", issue = "0")]
 #[doc(no_inline, hidden)]
 pub use self::stdio::{set_panic, set_print};
diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs
index 38ad23e14b3..a8b0bf0071a 100644
--- a/src/libstd/io/stdio.rs
+++ b/src/libstd/io/stdio.rs
@@ -17,7 +17,7 @@ use io::{self, BufReader, LineWriter};
 use sync::{Arc, Mutex, MutexGuard};
 use sys::stdio;
 use sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
-use thread::LocalKeyState;
+use thread::{LocalKey, LocalKeyState};
 
 /// Stdout used by print! and println! macros
 thread_local! {
@@ -659,41 +659,56 @@ pub fn set_print(sink: Option<Box<Write + Send>>) -> Option<Box<Write + Send>> {
     })
 }
 
-#[unstable(feature = "print",
-           reason = "implementation detail which may disappear or be replaced at any time",
-           issue = "0")]
-#[doc(hidden)]
-pub fn _print(args: fmt::Arguments) {
-    // As an implementation of the `println!` macro, we want to try our best to
-    // not panic wherever possible and get the output somewhere. There are
-    // currently two possible vectors for panics we take care of here:
-    //
-    // 1. If the TLS key for the local stdout has been destroyed, accessing it
-    //    would cause a panic. Note that we just lump in the uninitialized case
-    //    here for convenience, we're not trying to avoid a panic.
-    // 2. If the local stdout is currently in use (e.g. we're in the middle of
-    //    already printing) then accessing again would cause a panic.
-    //
-    // If, however, the actual I/O causes an error, we do indeed panic.
-    let result = match LOCAL_STDOUT.state() {
+/// Write `args` to output stream `local_s` if possible, `global_s`
+/// otherwise. `label` identifies the stream in a panic message.
+///
+/// This function is used to print error messages, so it takes extra
+/// care to avoid causing a panic when `local_stream` is unusable.
+/// For instance, if the TLS key for the local stream is uninitialized
+/// or already destroyed, or if the local stream is locked by another
+/// thread, it will just fall back to the global stream.
+///
+/// However, if the actual I/O causes an error, this function does panic.
+fn print_to<T>(args: fmt::Arguments,
+               local_s: &'static LocalKey<RefCell<Option<Box<Write+Send>>>>,
+               global_s: fn() -> T,
+               label: &str) where T: Write {
+    let result = match local_s.state() {
         LocalKeyState::Uninitialized |
-        LocalKeyState::Destroyed => stdout().write_fmt(args),
+        LocalKeyState::Destroyed => global_s().write_fmt(args),
         LocalKeyState::Valid => {
-            LOCAL_STDOUT.with(|s| {
+            local_s.with(|s| {
                 if let Ok(mut borrowed) = s.try_borrow_mut() {
                     if let Some(w) = borrowed.as_mut() {
                         return w.write_fmt(args);
                     }
                 }
-                stdout().write_fmt(args)
+                global_s().write_fmt(args)
             })
         }
     };
     if let Err(e) = result {
-        panic!("failed printing to stdout: {}", e);
+        panic!("failed printing to {}: {}", label, e);
     }
 }
 
+#[unstable(feature = "print_internals",
+           reason = "implementation detail which may disappear or be replaced at any time",
+           issue = "0")]
+#[doc(hidden)]
+pub fn _print(args: fmt::Arguments) {
+    print_to(args, &LOCAL_STDOUT, stdout, "stdout");
+}
+
+#[unstable(feature = "print_internals",
+           reason = "implementation detail which may disappear or be replaced at any time",
+           issue = "0")]
+#[doc(hidden)]
+pub fn _eprint(args: fmt::Arguments) {
+    use panicking::LOCAL_STDERR;
+    print_to(args, &LOCAL_STDERR, stderr, "stderr");
+}
+
 #[cfg(test)]
 mod tests {
     use thread;
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index a1f092621cb..ef78ea6dfe8 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -68,6 +68,9 @@ macro_rules! panic {
 /// necessary to use `io::stdout().flush()` to ensure the output is emitted
 /// immediately.
 ///
+/// Use `print!` only for the primary output of your program.  Use
+/// `eprint!` instead to print error and progress messages.
+///
 /// # Panics
 ///
 /// Panics if writing to `io::stdout()` fails.
@@ -105,9 +108,12 @@ macro_rules! print {
 /// Use the `format!` syntax to write data to the standard output.
 /// See `std::fmt` for more information.
 ///
+/// Use `println!` only for the primary output of your program.  Use
+/// `eprintln!` instead to print error and progress messages.
+///
 /// # Panics
 ///
-/// Panics if writing to `io::stdout()` fails.
+/// Panics if writing to `io::stdout` fails.
 ///
 /// # Examples
 ///
@@ -124,6 +130,45 @@ macro_rules! println {
     ($fmt:expr, $($arg:tt)*) => (print!(concat!($fmt, "\n"), $($arg)*));
 }
 
+/// Macro for printing to the standard error.
+///
+/// Equivalent to the `print!` macro, except that output goes to
+/// `io::stderr` instead of `io::stdout`.  See `print!` for
+/// example usage.
+///
+/// Use `eprint!` only for error and progress messages.  Use `print!`
+/// instead for the primary output of your program.
+///
+/// # Panics
+///
+/// Panics if writing to `io::stderr` fails.
+#[macro_export]
+#[stable(feature = "eprint", since="1.18.0")]
+#[allow_internal_unstable]
+macro_rules! eprint {
+    ($($arg:tt)*) => ($crate::io::_eprint(format_args!($($arg)*)));
+}
+
+/// Macro for printing to the standard error, with a newline.
+///
+/// Equivalent to the `println!` macro, except that output goes to
+/// `io::stderr` instead of `io::stdout`.  See `println!` for
+/// example usage.
+///
+/// Use `eprintln!` only for error and progress messages.  Use `println!`
+/// instead for the primary output of your program.
+///
+/// # Panics
+///
+/// Panics if writing to `io::stderr` fails.
+#[macro_export]
+#[stable(feature = "eprint", since="1.18.0")]
+macro_rules! eprintln {
+    () => (eprint!("\n"));
+    ($fmt:expr) => (eprint!(concat!($fmt, "\n")));
+    ($fmt:expr, $($arg:tt)*) => (eprint!(concat!($fmt, "\n"), $($arg)*));
+}
+
 /// A macro to select an event from a number of receivers.
 ///
 /// This macro is used to wait for the first event to occur on a number of
diff --git a/src/test/incremental/remove_source_file/auxiliary/mod.rs b/src/test/incremental/remove_source_file/auxiliary/mod.rs
new file mode 100644
index 00000000000..a2cea65a309
--- /dev/null
+++ b/src/test/incremental/remove_source_file/auxiliary/mod.rs
@@ -0,0 +1,13 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub fn print_hello() {
+    println!("hello");
+}
diff --git a/src/test/incremental/remove_source_file/main.rs b/src/test/incremental/remove_source_file/main.rs
new file mode 100644
index 00000000000..4ba33f3bb3d
--- /dev/null
+++ b/src/test/incremental/remove_source_file/main.rs
@@ -0,0 +1,31 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// This test case makes sure that the compiler doesn't crash due to a failing
+// table lookup when a source file is removed.
+
+// revisions:rpass1 rpass2
+
+// Note that we specify -g so that the FileMaps actually get referenced by the
+// incr. comp. cache:
+// compile-flags: -Z query-dep-graph -g
+
+#[cfg(rpass1)]
+mod auxiliary;
+
+#[cfg(rpass1)]
+fn main() {
+    auxiliary::print_hello();
+}
+
+#[cfg(rpass2)]
+fn main() {
+    println!("hello");
+}
diff --git a/src/test/run-pass/print-stdout-eprint-stderr.rs b/src/test/run-pass/print-stdout-eprint-stderr.rs
new file mode 100644
index 00000000000..0a0f30aba72
--- /dev/null
+++ b/src/test/run-pass/print-stdout-eprint-stderr.rs
@@ -0,0 +1,40 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-emscripten spawning processes is not supported
+
+use std::{env, process};
+
+fn child() {
+    print!("[stdout 0]");
+    print!("[stdout {}]", 1);
+    println!("[stdout {}]", 2);
+    println!();
+    eprint!("[stderr 0]");
+    eprint!("[stderr {}]", 1);
+    eprintln!("[stderr {}]", 2);
+    eprintln!();
+}
+
+fn parent() {
+    let this = env::args().next().unwrap();
+    let output = process::Command::new(this).arg("-").output().unwrap();
+    assert!(output.status.success());
+
+    let stdout = String::from_utf8(output.stdout).unwrap();
+    let stderr = String::from_utf8(output.stderr).unwrap();
+
+    assert_eq!(stdout, "[stdout 0][stdout 1][stdout 2]\n\n");
+    assert_eq!(stderr, "[stderr 0][stderr 1][stderr 2]\n\n");
+}
+
+fn main() {
+    if env::args().count() == 2 { child() } else { parent() }
+}
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index a044282666d..461cb59bf7d 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -647,6 +647,11 @@ actual:\n\
                                              exe_file.to_str().unwrap()
                                              .replace(r"\", r"\\")));
 
+                // Force GDB to print values in the Rust format.
+                if self.config.gdb_native_rust {
+                    script_str.push_str("set language rust\n");
+                }
+
                 // Add line breakpoints
                 for line in &breakpoint_lines {
                     script_str.push_str(&format!("break '{}':{}\n",