incr.comp.: Remove default serialization implementations for things in rustc::hir::def_id so that we get an ICE instead of silently doing the wrong thing.

src/librustc/hir/def_id.rs

@@ -11,8 +11,7 @@
 use ty;
 
 use rustc_data_structures::indexed_vec::Idx;
-use serialize::{self, Encoder, Decoder, Decodable, Encodable};
-
+use serialize;
 use std::fmt;
 use std::u32;
 
@@ -65,17 +64,8 @@ impl fmt::Display for CrateNum {
     }
 }
 
-impl serialize::UseSpecializedEncodable for CrateNum {
-    fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_u32(self.0)
-    }
-}
-
-impl serialize::UseSpecializedDecodable for CrateNum {
-    fn default_decode<D: Decoder>(d: &mut D) -> Result<CrateNum, D::Error> {
-        d.read_u32().map(CrateNum)
-    }
-}
+impl serialize::UseSpecializedEncodable for CrateNum {}
+impl serialize::UseSpecializedDecodable for CrateNum {}
 
 /// A DefIndex is an index into the hir-map for a crate, identifying a
 /// particular definition. It should really be considered an interned
@@ -151,19 +141,8 @@ impl DefIndex {
     }
 }
 
-impl serialize::UseSpecializedEncodable for DefIndex {
-    #[inline]
-    fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_u32(self.0)
-    }
-}
-
-impl serialize::UseSpecializedDecodable for DefIndex {
-    #[inline]
-    fn default_decode<D: Decoder>(d: &mut D) -> Result<DefIndex, D::Error> {
-        d.read_u32().map(DefIndex)
-    }
-}
+impl serialize::UseSpecializedEncodable for DefIndex {}
+impl serialize::UseSpecializedDecodable for DefIndex {}
 
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub enum DefIndexAddressSpace {
@@ -225,31 +204,8 @@ impl DefId {
     }
 }
 
-impl serialize::UseSpecializedEncodable for DefId {
-    #[inline]
-    fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        let DefId {
-            krate,
-            index,
-        } = *self;
-
-        krate.encode(s)?;
-        index.encode(s)
-    }
-}
-
-impl serialize::UseSpecializedDecodable for DefId {
-    #[inline]
-    fn default_decode<D: Decoder>(d: &mut D) -> Result<DefId, D::Error> {
-        let krate = CrateNum::decode(d)?;
-        let index = DefIndex::decode(d)?;
-
-        Ok(DefId {
-            krate,
-            index
-        })
-    }
-}
+impl serialize::UseSpecializedEncodable for DefId {}
+impl serialize::UseSpecializedDecodable for DefId {}
 
 
 #[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]

src/librustc/middle/cstore.rs

@@ -24,7 +24,7 @@
 
 use hir;
 use hir::def;
-use hir::def_id::{CrateNum, DefId, DefIndex, LOCAL_CRATE};
+use hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use hir::map as hir_map;
 use hir::map::definitions::{Definitions, DefKey, DefPathTable};
 use hir::svh::Svh;
@@ -180,7 +180,7 @@ impl EncodedMetadata {
 /// upstream crate.
 #[derive(Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
 pub struct EncodedMetadataHash {
-    pub def_index: DefIndex,
+    pub def_index: u32,
     pub hash: ich::Fingerprint,
 }
 

src/librustc/session/config.rs

@@ -1042,7 +1042,7 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "enable incremental compilation (experimental)"),
     incremental_cc: bool = (false, parse_bool, [UNTRACKED],
           "enable cross-crate incremental compilation (even more experimental)"),
-    incremental_queries: bool = (false, parse_bool, [UNTRACKED],
+    incremental_queries: bool = (true, parse_bool, [UNTRACKED],
           "enable incremental compilation support for queries (experimental)"),
     incremental_info: bool = (false, parse_bool, [UNTRACKED],
         "print high-level information about incremental reuse (or the lack thereof)"),

src/librustc/ty/maps/on_disk_cache.rs

@@ -559,14 +559,25 @@ impl<'enc, 'a, 'tcx, E> CacheEncoder<'enc, 'a, 'tcx, E>
 impl<'enc, 'a, 'tcx, E> ty_codec::TyEncoder for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn position(&self) -> usize {
         self.encoder.position()
     }
 }
 
+impl<'enc, 'a, 'tcx, E> SpecializedEncoder<CrateNum> for CacheEncoder<'enc, 'a, 'tcx, E>
+    where E: 'enc + ty_codec::TyEncoder
+{
+    #[inline]
+    fn specialized_encode(&mut self, cnum: &CrateNum) -> Result<(), Self::Error> {
+        self.emit_u32(cnum.as_u32())
+    }
+}
+
 impl<'enc, 'a, 'tcx, E> SpecializedEncoder<ty::Ty<'tcx>> for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self, ty: &ty::Ty<'tcx>) -> Result<(), Self::Error> {
         ty_codec::encode_with_shorthand(self, ty,
             |encoder| &mut encoder.type_shorthands)
@@ -577,6 +588,7 @@ impl<'enc, 'a, 'tcx, E> SpecializedEncoder<ty::GenericPredicates<'tcx>>
     for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self,
                           predicates: &ty::GenericPredicates<'tcx>)
                           -> Result<(), Self::Error> {
@@ -588,6 +600,7 @@ impl<'enc, 'a, 'tcx, E> SpecializedEncoder<ty::GenericPredicates<'tcx>>
 impl<'enc, 'a, 'tcx, E> SpecializedEncoder<hir::HirId> for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self, id: &hir::HirId) -> Result<(), Self::Error> {
         let hir::HirId {
             owner,
@@ -605,6 +618,7 @@ impl<'enc, 'a, 'tcx, E> SpecializedEncoder<hir::HirId> for CacheEncoder<'enc, 'a
 impl<'enc, 'a, 'tcx, E> SpecializedEncoder<DefId> for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self, id: &DefId) -> Result<(), Self::Error> {
         let def_path_hash = self.tcx.def_path_hash(*id);
         def_path_hash.encode(self)
@@ -614,6 +628,7 @@ impl<'enc, 'a, 'tcx, E> SpecializedEncoder<DefId> for CacheEncoder<'enc, 'a, 'tc
 impl<'enc, 'a, 'tcx, E> SpecializedEncoder<LocalDefId> for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self, id: &LocalDefId) -> Result<(), Self::Error> {
         id.to_def_id().encode(self)
     }
@@ -632,6 +647,7 @@ impl<'enc, 'a, 'tcx, E> SpecializedEncoder<DefIndex> for CacheEncoder<'enc, 'a,
 impl<'enc, 'a, 'tcx, E> SpecializedEncoder<NodeId> for CacheEncoder<'enc, 'a, 'tcx, E>
     where E: 'enc + ty_codec::TyEncoder
 {
+    #[inline]
     fn specialized_encode(&mut self, node_id: &NodeId) -> Result<(), Self::Error> {
         let hir_id = self.tcx.hir.node_to_hir_id(*node_id);
         hir_id.encode(self)