incr.comp.: Implement query result cache and use it to cache type checking tables.

src/librustc/dep_graph/dep_node.rs

@@ -618,7 +618,7 @@ define_dep_nodes!( <'tcx>
 
     [input] Freevars(DefId),
     [input] MaybeUnusedTraitImport(DefId),
-    [] MaybeUnusedExternCrates,
+    [input] MaybeUnusedExternCrates,
     [] StabilityIndex,
     [input] AllCrateNums,
     [] ExportedSymbols(CrateNum),

src/librustc/dep_graph/graph.rs

@@ -327,6 +327,7 @@ impl DepGraph {
         }
     }
 
+    #[inline]
     pub fn fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {
         match self.fingerprints.borrow().get(dep_node) {
             Some(&fingerprint) => fingerprint,
@@ -340,6 +341,11 @@ impl DepGraph {
         self.data.as_ref().unwrap().previous.fingerprint_of(dep_node)
     }
 
+    #[inline]
+    pub fn prev_dep_node_index_of(&self, dep_node: &DepNode) -> SerializedDepNodeIndex {
+        self.data.as_ref().unwrap().previous.node_to_index(dep_node)
+    }
+
     /// Indicates that a previous work product exists for `v`. This is
     /// invoked during initial start-up based on what nodes are clean
     /// (and what files exist in the incr. directory).

src/librustc/dep_graph/prev.rs

@@ -44,6 +44,11 @@ impl PreviousDepGraph {
         self.data.nodes[dep_node_index].0
     }
 
+    #[inline]
+    pub fn node_to_index(&self, dep_node: &DepNode) -> SerializedDepNodeIndex {
+        self.index[dep_node]
+    }
+
     #[inline]
     pub fn fingerprint_of(&self, dep_node: &DepNode) -> Option<Fingerprint> {
         self.index

src/librustc/hir/def_id.rs

@@ -11,7 +11,7 @@
 use ty;
 
 use rustc_data_structures::indexed_vec::Idx;
-use serialize::{self, Encoder, Decoder};
+use serialize::{self, Encoder, Decoder, Decodable, Encodable};
 
 use std::fmt;
 use std::u32;
@@ -32,6 +32,10 @@ newtype_index!(CrateNum
 
         /// A CrateNum value that indicates that something is wrong.
         const INVALID_CRATE = u32::MAX - 1,
+
+        /// A special CrateNum that we use for the tcx.rcache when decoding from
+        /// the incr. comp. cache.
+        const RESERVED_FOR_INCR_COMP_CACHE = u32::MAX - 2,
     });
 
 impl CrateNum {
@@ -146,6 +150,20 @@ 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)
+    }
+}
+
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub enum DefIndexAddressSpace {
     Low = 0,
@@ -166,7 +184,7 @@ impl DefIndexAddressSpace {
 
 /// A DefId identifies a particular *definition*, by combining a crate
 /// index and a def index.
-#[derive(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable, RustcDecodable, Hash, Copy)]
+#[derive(Clone, Eq, Ord, PartialOrd, PartialEq, Hash, Copy)]
 pub struct DefId {
     pub krate: CrateNum,
     pub index: DefIndex,
@@ -188,7 +206,6 @@ impl fmt::Debug for DefId {
     }
 }
 
-
 impl DefId {
     /// Make a local `DefId` with the given index.
     pub fn local(index: DefIndex) -> DefId {
@@ -199,3 +216,29 @@ impl DefId {
         self.krate == LOCAL_CRATE
     }
 }
+
+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
+        })
+    }
+}

src/librustc/hir/mod.rs

@@ -45,6 +45,7 @@ use ty::AdtKind;
 
 use rustc_data_structures::indexed_vec;
 
+use serialize::{self, Encoder, Encodable, Decoder, Decodable};
 use std::collections::BTreeMap;
 use std::fmt;
 
@@ -85,13 +86,37 @@ pub mod svh;
 /// the local_id part of the HirId changing, which is a very useful property in
 /// incremental compilation where we have to persist things through changes to
 /// the code base.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug,
-         RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
 pub struct HirId {
     pub owner: DefIndex,
     pub local_id: ItemLocalId,
 }
 
+impl serialize::UseSpecializedEncodable for HirId {
+    fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        let HirId {
+            owner,
+            local_id,
+        } = *self;
+
+        owner.encode(s)?;
+        local_id.encode(s)
+    }
+}
+
+impl serialize::UseSpecializedDecodable for HirId {
+    fn default_decode<D: Decoder>(d: &mut D) -> Result<HirId, D::Error> {
+        let owner = DefIndex::decode(d)?;
+        let local_id = ItemLocalId::decode(d)?;
+
+        Ok(HirId {
+            owner,
+            local_id
+        })
+    }
+}
+
+
 /// An `ItemLocalId` uniquely identifies something within a given "item-like",
 /// that is within a hir::Item, hir::TraitItem, or hir::ImplItem. There is no
 /// guarantee that the numerical value of a given `ItemLocalId` corresponds to

src/librustc/session/config.rs

@@ -1042,6 +1042,8 @@ 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],
+          "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)"),
     incremental_dump_hash: bool = (false, parse_bool, [UNTRACKED],

src/librustc/ty/codec.rs

@@ -19,7 +19,7 @@
 use hir::def_id::{DefId, CrateNum};
 use middle::const_val::ByteArray;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_serialize::{Decodable, Decoder, Encoder, Encodable};
+use rustc_serialize::{Decodable, Decoder, Encoder, Encodable, opaque};
 use std::hash::Hash;
 use std::intrinsics;
 use ty::{self, Ty, TyCtxt};
@@ -53,6 +53,13 @@ pub trait TyEncoder: Encoder {
     fn position(&self) -> usize;
 }
 
+impl<'buf> TyEncoder for opaque::Encoder<'buf> {
+    #[inline]
+    fn position(&self) -> usize {
+        self.position()
+    }
+}
+
 /// Encode the given value or a previously cached shorthand.
 pub fn encode_with_shorthand<E, T, M>(encoder: &mut E,
                                       value: &T,
@@ -113,6 +120,8 @@ pub trait TyDecoder<'a, 'tcx: 'a>: Decoder {
 
     fn peek_byte(&self) -> u8;
 
+    fn position(&self) -> usize;
+
     fn cached_ty_for_shorthand<F>(&mut self,
                                   shorthand: usize,
                                   or_insert_with: F)
@@ -142,7 +151,6 @@ pub fn decode_ty<'a, 'tcx, D>(decoder: &mut D) -> Result<Ty<'tcx>, D::Error>
           'tcx: 'a,
 {
     // Handle shorthands first, if we have an usize > 0x80.
-    // if self.opaque.data[self.opaque.position()] & 0x80 != 0 {
     if decoder.positioned_at_shorthand() {
         let pos = decoder.read_usize()?;
         assert!(pos >= SHORTHAND_OFFSET);

src/librustc/ty/context.rs

@@ -1311,9 +1311,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     pub fn serialize_query_result_cache<E>(self,
                                            encoder: &mut E)
                                            -> Result<(), E::Error>
-        where E: ::rustc_serialize::Encoder
+        where E: ty::codec::TyEncoder
     {
-        self.on_disk_query_result_cache.serialize(encoder)
+        self.on_disk_query_result_cache.serialize(self.global_tcx(), self.cstore, encoder)
     }
 
 }