crate_num_2.patch

diff --git a/src/librustc/hir/def_id.rs b/src/librustc/hir/def_id.rs
index 8e48352007..6552b3d450 100644
--- a/src/librustc/hir/def_id.rs
+++ b/src/librustc/hir/def_id.rs
@@ -16,37 +16,20 @@ use serialize::{self, Encoder, Decoder};
 use std::fmt;
 use std::u32;
 
-#[derive(Clone, Copy, Eq, Ord, PartialOrd, PartialEq, Hash, Debug)]
-pub struct CrateNum(u32);
-
-impl Idx for CrateNum {
-    fn new(value: usize) -> Self {
-        assert!(value < (u32::MAX) as usize);
-        CrateNum(value as u32)
-    }
-
-    fn index(self) -> usize {
-        self.0 as usize
-    }
-}
+newtype_index!(CrateNum);
 
 /// Item definitions in the currently-compiled crate would have the CrateNum
 /// LOCAL_CRATE in their DefId.
-pub const LOCAL_CRATE: CrateNum = CrateNum(0);
+pub const LOCAL_CRATE: CrateNum = CrateNum::const_new(0);
 
 /// Virtual crate for builtin macros
 // FIXME(jseyfried): this is also used for custom derives until proc-macro crates get `CrateNum`s.
-pub const BUILTIN_MACROS_CRATE: CrateNum = CrateNum(u32::MAX);
+pub const BUILTIN_MACROS_CRATE: CrateNum = CrateNum::const_new(u32::MAX);
 
 /// A CrateNum value that indicates that something is wrong.
-pub const INVALID_CRATE: CrateNum = CrateNum(u32::MAX - 1);
+pub const INVALID_CRATE: CrateNum = CrateNum::const_new(u32::MAX - 1);
 
 impl CrateNum {
-    pub fn new(x: usize) -> CrateNum {
-        assert!(x < (u32::MAX as usize));
-        CrateNum(x as u32)
-    }
-
     pub fn from_u32(x: u32) -> CrateNum {
         CrateNum(x)
     }
diff --git a/src/librustc/middle/dependency_format.rs b/src/librustc/middle/dependency_format.rs
index db0ecb6aa5..6548d8d3ac 100644
--- a/src/librustc/middle/dependency_format.rs
+++ b/src/librustc/middle/dependency_format.rs
@@ -70,6 +70,7 @@ use middle::cstore::{self, DepKind};
 use middle::cstore::LinkagePreference::{self, RequireStatic, RequireDynamic};
 use util::nodemap::FxHashMap;
 use rustc_back::PanicStrategy;
+use rustc_data_structures::indexed_vec::Idx;
 
 /// A list of dependencies for a certain crate type.
 ///
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index bc5a056dd3..a7426ba3db 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -2334,9 +2334,10 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn adjust_ident(self, mut ident: Ident, scope: DefId, block: NodeId) -> (Ident, DefId) {
-        let expansion = match scope.krate {
-            LOCAL_CRATE => self.hir.definitions().expansion(scope.index),
-            _ => Mark::root(),
+        let expansion = if scope.is_local() {
+            self.hir.definitions().expansion(scope.index)
+        } else {
+            Mark::root()
         };
         let scope = match ident.ctxt.adjust(expansion) {
             Some(macro_def) => self.hir.definitions().macro_def_scope(macro_def),
diff --git a/src/librustc_metadata/cstore.rs b/src/librustc_metadata/cstore.rs
index 9e47e96aee..24d0003ea7 100644
--- a/src/librustc_metadata/cstore.rs
+++ b/src/librustc_metadata/cstore.rs
@@ -18,7 +18,7 @@ use rustc::hir::map::definitions::DefPathTable;
 use rustc::hir::svh::Svh;
 use rustc::middle::cstore::{DepKind, ExternCrate, MetadataLoader};
 use rustc_back::PanicStrategy;
-use rustc_data_structures::indexed_vec::IndexVec;
+use rustc_data_structures::indexed_vec::{IndexVec, Idx};
 use rustc::util::nodemap::{FxHashMap, FxHashSet, NodeMap};
 
 use std::cell::{RefCell, Cell};
diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs
index 65cf15e5a0..87a899661c 100644
--- a/src/librustc_metadata/decoder.rs
+++ b/src/librustc_metadata/decoder.rs
@@ -40,6 +40,7 @@ use std::str;
 use std::u32;
 
 use rustc_serialize::{Decodable, Decoder, SpecializedDecoder, opaque};
+use rustc_data_structures::indexed_vec::Idx;
 use syntax::attr;
 use syntax::ast::{self, Ident};
 use syntax::codemap;
diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 6b49be3e12..72eb9ddc2e 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -29,6 +29,7 @@ use rustc::ty::{self, Ty, TyCtxt, ReprOptions};
 use rustc::session::config::{self, CrateTypeProcMacro};
 use rustc::util::nodemap::{FxHashMap, NodeSet};
 
+use rustc_data_structures::indexed_vec::Idx;
 use rustc_serialize::{Encodable, Encoder, SpecializedEncoder, opaque};
 
 use std::hash::Hash;
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 36cd69f91b..4e9d530380 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -35,7 +35,7 @@ use rustc::middle::cstore::{CrateStore, CrateLoader};
 use rustc::session::Session;
 use rustc::lint;
 use rustc::hir::def::*;
-use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
+use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
 use rustc::ty;
 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
 use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
@@ -1353,9 +1353,10 @@ impl<'a> ResolverArenas<'a> {
 
 impl<'a, 'b: 'a> ty::DefIdTree for &'a Resolver<'b> {
     fn parent(self, id: DefId) -> Option<DefId> {
-        match id.krate {
-            LOCAL_CRATE => self.definitions.def_key(id.index).parent,
-            _ => self.cstore.def_key(id).parent,
+        if id.is_local() {
+            self.definitions.def_key(id.index).parent
+        } else {
+            self.cstore.def_key(id).parent
         }.map(|index| DefId { index: index, ..id })
     }
 }
diff --git a/src/librustc_trans/back/linker.rs b/src/librustc_trans/back/linker.rs
index 99422bf8c9..bda7afdbeb 100644
--- a/src/librustc_trans/back/linker.rs
+++ b/src/librustc_trans/back/linker.rs
@@ -24,6 +24,7 @@ use rustc::session::Session;
 use rustc::session::config::{self, CrateType, OptLevel, DebugInfoLevel};
 use rustc::ty::TyCtxt;
 use rustc_back::LinkerFlavor;
+use rustc_data_structures::indexed_vec::Idx;
 use serialize::{json, Encoder};
 
 /// For all the linkers we support, and information they might