serialize: Fully deprecate the library

This commit completes the deprecation story for the in-tree serialization
library. The compiler will now emit a warning whenever it encounters
`deriving(Encodable)` or `deriving(Decodable)`, and the library itself is now
marked `#[unstable]` for when feature staging is enabled.

All users of serialization can migrate to the `rustc-serialize` crate on
crates.io which provides the exact same interface as the libserialize library
in-tree. The new deriving modes are named `RustcEncodable` and `RustcDecodable`
and require `extern crate "rustc-serialize" as rustc_serialize` at the crate
root in order to expand correctly.

To migrate all crates, add the following to your `Cargo.toml`:

    [dependencies]
    rustc-serialize = "0.1.1"

And then add the following to your crate root:

    extern crate "rustc-serialize" as rustc_serialize;

Finally, rename `Encodable` and `Decodable` deriving modes to `RustcEncodable`
and `RustcDecodable`.

[breaking-change]

11 files changed, 181 insertions, 135 deletions

diff --git a/src/libsyntax/abi.rs b/src/libsyntax/abi.rs
index 70bad90aea1..b1599cb807d 100644
--- a/src/libsyntax/abi.rs
+++ b/src/libsyntax/abi.rs
@@ -26,7 +26,7 @@ pub enum Os {
     OsDragonfly,
 }
 
-#[deriving(Copy, PartialEq, Eq, Hash, Encodable, Decodable, Clone)]
+#[deriving(PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Clone, Copy)]
 pub enum Abi {
     // NB: This ordering MUST match the AbiDatas array below.
     // (This is ensured by the test indices_are_correct().)
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index a294706ef2c..b37914ed429 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -157,7 +157,8 @@ pub const ILLEGAL_CTXT : SyntaxContext = 1;
 
 /// A name is a part of an identifier, representing a string or gensym. It's
 /// the result of interning.
-#[deriving(Copy, Eq, Ord, PartialEq, PartialOrd, Hash, Encodable, Decodable, Clone)]
+#[deriving(Eq, Ord, PartialEq, PartialOrd, Hash,
+           RustcEncodable, RustcDecodable, Clone, Copy)]
 pub struct Name(pub u32);
 
 impl Name {
@@ -187,7 +188,7 @@ impl<S: Encoder<E>, E> Encodable<S, E> for Ident {
     }
 }
 
-impl<D:Decoder<E>, E> Decodable<D, E> for Ident {
+impl<D: Decoder<E>, E> Decodable<D, E> for Ident {
     fn decode(d: &mut D) -> Result<Ident, E> {
         Ok(str_to_ident(try!(d.read_str()).as_slice()))
     }
@@ -196,14 +197,15 @@ impl<D:Decoder<E>, E> Decodable<D, E> for Ident {
 /// Function name (not all functions have names)
 pub type FnIdent = Option<Ident>;
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash,
+           Show, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
     pub span: Span,
     pub name: Name
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct LifetimeDef {
     pub lifetime: Lifetime,
     pub bounds: Vec<Lifetime>
@@ -212,7 +214,7 @@ pub struct LifetimeDef {
 /// A "Path" is essentially Rust's notion of a name; for instance:
 /// std::cmp::PartialEq  .  It's represented as a sequence of identifiers,
 /// along with a bunch of supporting information.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Path {
     pub span: Span,
     /// A `::foo` path, is relative to the crate root rather than current
@@ -224,7 +226,7 @@ pub struct Path {
 
 /// A segment of a path: an identifier, an optional lifetime, and a set of
 /// types.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct PathSegment {
     /// The identifier portion of this path segment.
     pub identifier: Ident,
@@ -237,7 +239,7 @@ pub struct PathSegment {
     pub parameters: PathParameters,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum PathParameters {
     AngleBracketedParameters(AngleBracketedParameterData),
     ParenthesizedParameters(ParenthesizedParameterData),
@@ -315,7 +317,7 @@ impl PathParameters {
 }
 
 /// A path like `Foo<'a, T>`
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct AngleBracketedParameterData {
     /// The lifetime parameters for this path segment.
     pub lifetimes: Vec<Lifetime>,
@@ -333,7 +335,7 @@ impl AngleBracketedParameterData {
 }
 
 /// A path like `Foo(A,B) -> C`
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct ParenthesizedParameterData {
     /// `(A,B)`
     pub inputs: Vec<P<Ty>>,
@@ -346,7 +348,8 @@ pub type CrateNum = u32;
 
 pub type NodeId = u32;
 
-#[deriving(Clone, Copy, Eq, Ord, PartialOrd, PartialEq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, Eq, Ord, PartialOrd, PartialEq, RustcEncodable,
+           RustcDecodable, Hash, Show, Copy)]
 pub struct DefId {
     pub krate: CrateNum,
     pub node: NodeId,
@@ -366,7 +369,7 @@ pub const DUMMY_NODE_ID: NodeId = -1;
 /// typeck::collect::compute_bounds matches these against
 /// the "special" built-in traits (see middle::lang_items) and
 /// detects Copy, Send and Sync.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum TyParamBound {
     TraitTyParamBound(PolyTraitRef),
     RegionTyParamBound(Lifetime)
@@ -374,7 +377,7 @@ pub enum TyParamBound {
 
 pub type TyParamBounds = OwnedSlice<TyParamBound>;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct TyParam {
     pub ident: Ident,
     pub id: NodeId,
@@ -386,7 +389,7 @@ pub struct TyParam {
 
 /// Represents lifetimes and type parameters attached to a declaration
 /// of a function, enum, trait, etc.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Generics {
     pub lifetimes: Vec<LifetimeDef>,
     pub ty_params: OwnedSlice<TyParam>,
@@ -405,34 +408,34 @@ impl Generics {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct WhereClause {
     pub id: NodeId,
     pub predicates: Vec<WherePredicate>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum WherePredicate {
     BoundPredicate(WhereBoundPredicate),
     RegionPredicate(WhereRegionPredicate),
     EqPredicate(WhereEqPredicate)
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct WhereBoundPredicate {
     pub span: Span,
     pub bounded_ty: P<Ty>,
     pub bounds: OwnedSlice<TyParamBound>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct WhereRegionPredicate {
     pub span: Span,
     pub lifetime: Lifetime,
     pub bounds: Vec<Lifetime>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct WhereEqPredicate {
     pub id: NodeId,
     pub span: Span,
@@ -444,7 +447,7 @@ pub struct WhereEqPredicate {
 /// used to drive conditional compilation
 pub type CrateConfig = Vec<P<MetaItem>> ;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Crate {
     pub module: Mod,
     pub attrs: Vec<Attribute>,
@@ -455,7 +458,7 @@ pub struct Crate {
 
 pub type MetaItem = Spanned<MetaItem_>;
 
-#[deriving(Clone, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum MetaItem_ {
     MetaWord(InternedString),
     MetaList(InternedString, Vec<P<MetaItem>>),
@@ -487,7 +490,7 @@ impl PartialEq for MetaItem_ {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Block {
     pub view_items: Vec<ViewItem>,
     pub stmts: Vec<P<Stmt>>,
@@ -497,27 +500,27 @@ pub struct Block {
     pub span: Span,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Pat {
     pub id: NodeId,
     pub node: Pat_,
     pub span: Span,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct FieldPat {
     pub ident: Ident,
     pub pat: P<Pat>,
     pub is_shorthand: bool,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum BindingMode {
     BindByRef(Mutability),
     BindByValue(Mutability),
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum PatWildKind {
     /// Represents the wildcard pattern `_`
     PatWildSingle,
@@ -526,7 +529,7 @@ pub enum PatWildKind {
     PatWildMulti,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Pat_ {
     /// Represents a wildcard pattern (either `_` or `..`)
     PatWild(PatWildKind),
@@ -555,13 +558,13 @@ pub enum Pat_ {
     PatMac(Mac),
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum Mutability {
     MutMutable,
     MutImmutable,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum BinOp {
     BiAdd,
     BiSub,
@@ -583,7 +586,7 @@ pub enum BinOp {
     BiGt,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum UnOp {
     UnUniq,
     UnDeref,
@@ -593,7 +596,7 @@ pub enum UnOp {
 
 pub type Stmt = Spanned<Stmt_>;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Stmt_ {
     /// Could be an item or a local (let) binding:
     StmtDecl(P<Decl>, NodeId),
@@ -607,7 +610,7 @@ pub enum Stmt_ {
     StmtMac(Mac, MacStmtStyle),
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum MacStmtStyle {
     /// The macro statement had a trailing semicolon, e.g. `foo! { ... };`
     /// `foo!(...);`, `foo![...];`
@@ -622,7 +625,7 @@ pub enum MacStmtStyle {
 
 /// Where a local declaration came from: either a true `let ... =
 /// ...;`, or one desugared from the pattern of a for loop.
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum LocalSource {
     LocalLet,
     LocalFor,
@@ -631,7 +634,7 @@ pub enum LocalSource {
 // FIXME (pending discussion of #1697, #2178...): local should really be
 // a refinement on pat.
 /// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Local {
     pub ty: P<Ty>,
     pub pat: P<Pat>,
@@ -643,7 +646,7 @@ pub struct Local {
 
 pub type Decl = Spanned<Decl_>;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Decl_ {
     /// A local (let) binding:
     DeclLocal(P<Local>),
@@ -652,7 +655,7 @@ pub enum Decl_ {
 }
 
 /// represents one arm of a 'match'
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Arm {
     pub attrs: Vec<Attribute>,
     pub pats: Vec<P<Pat>>,
@@ -660,7 +663,7 @@ pub struct Arm {
     pub body: P<Expr>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Field {
     pub ident: SpannedIdent,
     pub expr: P<Expr>,
@@ -669,26 +672,26 @@ pub struct Field {
 
 pub type SpannedIdent = Spanned<Ident>;
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum BlockCheckMode {
     DefaultBlock,
     UnsafeBlock(UnsafeSource),
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum UnsafeSource {
     CompilerGenerated,
     UserProvided,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Expr {
     pub id: NodeId,
     pub node: Expr_,
     pub span: Span,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Expr_ {
     /// First expr is the place; second expr is the value.
     ExprBox(Option<P<Expr>>, P<Expr>),
@@ -750,28 +753,28 @@ pub enum Expr_ {
 ///     <Vec<T> as SomeTrait>::SomeAssociatedItem
 ///      ^~~~~     ^~~~~~~~~   ^~~~~~~~~~~~~~~~~~
 ///      self_type  trait_name  item_name
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct QPath {
     pub self_type: P<Ty>,
     pub trait_ref: P<TraitRef>,
     pub item_name: Ident,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum MatchSource {
     Normal,
     IfLetDesugar { contains_else_clause: bool },
     WhileLetDesugar,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum CaptureClause {
     CaptureByValue,
     CaptureByRef,
 }
 
 /// A delimited sequence of token trees
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Delimited {
     /// The type of delimiter
     pub delim: token::DelimToken,
@@ -806,7 +809,7 @@ impl Delimited {
 }
 
 /// A sequence of token treesee
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct SequenceRepetition {
     /// The sequence of token trees
     pub tts: Vec<TokenTree>,
@@ -820,7 +823,7 @@ pub struct SequenceRepetition {
 
 /// A Kleene-style [repetition operator](http://en.wikipedia.org/wiki/Kleene_star)
 /// for token sequences.
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum KleeneOp {
     ZeroOrMore,
     OneOrMore,
@@ -838,7 +841,7 @@ pub enum KleeneOp {
 ///
 /// The RHS of an MBE macro is the only place `SubstNt`s are substituted.
 /// Nothing special happens to misnamed or misplaced `SubstNt`s.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 #[doc="For macro invocations; parsing is delegated to the macro"]
 pub enum TokenTree {
     /// A single token
@@ -928,14 +931,14 @@ pub type Mac = Spanned<Mac_>;
 /// is being invoked, and the vector of token-trees contains the source
 /// of the macro invocation.
 /// There's only one flavor, now, so this could presumably be simplified.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Mac_ {
     // NB: the additional ident for a macro_rules-style macro is actually
     // stored in the enclosing item. Oog.
     MacInvocTT(Path, Vec<TokenTree> , SyntaxContext),   // new macro-invocation
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum StrStyle {
     CookedStr,
     RawStr(uint)
@@ -943,7 +946,7 @@ pub enum StrStyle {
 
 pub type Lit = Spanned<Lit_>;
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum Sign {
     Minus,
     Plus
@@ -959,7 +962,7 @@ impl<T> Sign where T: Int {
     }
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum LitIntType {
     SignedIntLit(IntTy, Sign),
     UnsignedIntLit(UintTy),
@@ -976,7 +979,7 @@ impl LitIntType {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Lit_ {
     LitStr(InternedString, StrStyle),
     LitBinary(Rc<Vec<u8> >),
@@ -990,13 +993,13 @@ pub enum Lit_ {
 
 // NB: If you change this, you'll probably want to change the corresponding
 // type structure in middle/ty.rs as well.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct MutTy {
     pub ty: P<Ty>,
     pub mutbl: Mutability,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct TypeField {
     pub ident: Ident,
     pub mt: MutTy,
@@ -1005,7 +1008,7 @@ pub struct TypeField {
 
 /// Represents a required method in a trait declaration,
 /// one without a default implementation
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct TypeMethod {
     pub ident: Ident,
     pub attrs: Vec<Attribute>,
@@ -1023,26 +1026,26 @@ pub struct TypeMethod {
 /// a default implementation A trait method is either required (meaning it
 /// doesn't have an implementation, just a signature) or provided (meaning it
 /// has a default implementation).
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum TraitItem {
     RequiredMethod(TypeMethod),
     ProvidedMethod(P<Method>),
     TypeTraitItem(P<AssociatedType>),
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum ImplItem {
     MethodImplItem(P<Method>),
     TypeImplItem(P<Typedef>),
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct AssociatedType {
     pub attrs: Vec<Attribute>,
     pub ty_param: TyParam,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Typedef {
     pub id: NodeId,
     pub span: Span,
@@ -1052,7 +1055,7 @@ pub struct Typedef {
     pub typ: P<Ty>,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub enum IntTy {
     TyI,
     TyI8,
@@ -1077,7 +1080,7 @@ impl IntTy {
     }
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub enum UintTy {
     TyU,
     TyU8,
@@ -1102,7 +1105,7 @@ impl fmt::Show for UintTy {
     }
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub enum FloatTy {
     TyF32,
     TyF64,
@@ -1123,7 +1126,7 @@ impl FloatTy {
 }
 
 // Bind a type to an associated type: `A=Foo`.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct TypeBinding {
     pub id: NodeId,
     pub ident: Ident,
@@ -1133,7 +1136,7 @@ pub struct TypeBinding {
 
 
 // NB PartialEq method appears below.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Ty {
     pub id: NodeId,
     pub node: Ty_,
@@ -1141,7 +1144,7 @@ pub struct Ty {
 }
 
 /// Not represented directly in the AST, referred to by name through a ty_path.
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum PrimTy {
     TyInt(IntTy),
     TyUint(UintTy),
@@ -1151,7 +1154,7 @@ pub enum PrimTy {
     TyChar
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub enum Onceness {
     Once,
     Many
@@ -1167,7 +1170,7 @@ impl fmt::Show for Onceness {
 }
 
 /// Represents the type of a closure
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct ClosureTy {
     pub lifetimes: Vec<LifetimeDef>,
     pub unsafety: Unsafety,
@@ -1176,7 +1179,7 @@ pub struct ClosureTy {
     pub bounds: TyParamBounds,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct BareFnTy {
     pub unsafety: Unsafety,
     pub abi: Abi,
@@ -1184,7 +1187,7 @@ pub struct BareFnTy {
     pub decl: P<FnDecl>
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 /// The different kinds of types recognized by the compiler
 pub enum Ty_ {
     TyVec(P<Ty>),
@@ -1219,13 +1222,13 @@ pub enum Ty_ {
     TyInfer,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum AsmDialect {
     AsmAtt,
     AsmIntel
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct InlineAsm {
     pub asm: InternedString,
     pub asm_str_style: StrStyle,
@@ -1239,7 +1242,7 @@ pub struct InlineAsm {
 }
 
 /// represents an argument in a function header
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Arg {
     pub ty: P<Ty>,
     pub pat: P<Pat>,
@@ -1267,14 +1270,14 @@ impl Arg {
 }
 
 /// represents the header (not the body) of a function declaration
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct FnDecl {
     pub inputs: Vec<Arg>,
     pub output: FunctionRetTy,
     pub variadic: bool
 }
 
-#[deriving(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash)]
+#[deriving(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub enum Unsafety {
     Unsafe,
     Normal,
@@ -1289,7 +1292,7 @@ impl fmt::Show for Unsafety {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum FunctionRetTy {
     /// Functions with return type ! that always
     /// raise an error or exit (i.e. never return to the caller)
@@ -1308,7 +1311,7 @@ impl FunctionRetTy {
 }
 
 /// Represents the kind of 'self' associated with a method
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum ExplicitSelf_ {
     /// No self
     SelfStatic,
@@ -1322,7 +1325,7 @@ pub enum ExplicitSelf_ {
 
 pub type ExplicitSelf = Spanned<ExplicitSelf_>;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Method {
     pub attrs: Vec<Attribute>,
     pub id: NodeId,
@@ -1330,7 +1333,7 @@ pub struct Method {
     pub node: Method_,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Method_ {
     /// Represents a method declaration
     MethDecl(Ident,
@@ -1345,7 +1348,7 @@ pub enum Method_ {
     MethMac(Mac),
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Mod {
     /// A span from the first token past `{` to the last token until `}`.
     /// For `mod foo;`, the inner span ranges from the first token
@@ -1355,31 +1358,31 @@ pub struct Mod {
     pub items: Vec<P<Item>>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct ForeignMod {
     pub abi: Abi,
     pub view_items: Vec<ViewItem>,
     pub items: Vec<P<ForeignItem>>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct VariantArg {
     pub ty: P<Ty>,
     pub id: NodeId,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum VariantKind {
     TupleVariantKind(Vec<VariantArg>),
     StructVariantKind(P<StructDef>),
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct EnumDef {
     pub variants: Vec<P<Variant>>,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Variant_ {
     pub name: Ident,
     pub attrs: Vec<Attribute>,
@@ -1391,7 +1394,7 @@ pub struct Variant_ {
 
 pub type Variant = Spanned<Variant_>;
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum PathListItem_ {
     PathListIdent { name: Ident, id: NodeId },
     PathListMod { id: NodeId }
@@ -1409,7 +1412,7 @@ pub type PathListItem = Spanned<PathListItem_>;
 
 pub type ViewPath = Spanned<ViewPath_>;
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum ViewPath_ {
 
     /// `foo::bar::baz as quux`
@@ -1426,7 +1429,7 @@ pub enum ViewPath_ {
     ViewPathList(Path, Vec<PathListItem> , NodeId)
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct ViewItem {
     pub node: ViewItem_,
     pub attrs: Vec<Attribute>,
@@ -1434,7 +1437,7 @@ pub struct ViewItem {
     pub span: Span,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum ViewItem_ {
     /// Ident: name used to refer to this crate in the code
     /// optional (InternedString,StrStyle): if present, this is a location
@@ -1450,17 +1453,17 @@ pub type Attribute = Spanned<Attribute_>;
 /// Distinguishes between Attributes that decorate items and Attributes that
 /// are contained as statements within items. These two cases need to be
 /// distinguished for pretty-printing.
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum AttrStyle {
     AttrOuter,
     AttrInner,
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub struct AttrId(pub uint);
 
 /// Doc-comments are promoted to attributes that have is_sugared_doc = true
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Attribute_ {
     pub id: AttrId,
     pub style: AttrStyle,
@@ -1473,13 +1476,13 @@ pub struct Attribute_ {
 /// that the ref_id is for. The impl_id maps to the "self type" of this impl.
 /// If this impl is an ItemImpl, the impl_id is redundant (it could be the
 /// same as the impl's node id).
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct TraitRef {
     pub path: Path,
     pub ref_id: NodeId,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct PolyTraitRef {
     /// The `'a` in `<'a> Foo<&'a T>`
     pub bound_lifetimes: Vec<LifetimeDef>,
@@ -1488,7 +1491,7 @@ pub struct PolyTraitRef {
     pub trait_ref: TraitRef
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum Visibility {
     Public,
     Inherited,
@@ -1503,7 +1506,7 @@ impl Visibility {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct StructField_ {
     pub kind: StructFieldKind,
     pub id: NodeId,
@@ -1522,7 +1525,7 @@ impl StructField_ {
 
 pub type StructField = Spanned<StructField_>;
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum StructFieldKind {
     NamedField(Ident, Visibility),
     /// Element of a tuple-like struct
@@ -1538,7 +1541,7 @@ impl StructFieldKind {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct StructDef {
     /// Fields, not including ctor
     pub fields: Vec<StructField>,
@@ -1551,7 +1554,7 @@ pub struct StructDef {
   FIXME (#3300): Should allow items to be anonymous. Right now
   we just use dummy names for anon items.
  */
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Item {
     pub ident: Ident,
     pub attrs: Vec<Attribute>,
@@ -1561,7 +1564,7 @@ pub struct Item {
     pub span: Span,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum Item_ {
     ItemStatic(P<Ty>, Mutability, P<Expr>),
     ItemConst(P<Ty>, P<Expr>),
@@ -1605,7 +1608,7 @@ impl Item_ {
     }
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct ForeignItem {
     pub ident: Ident,
     pub attrs: Vec<Attribute>,
@@ -1615,7 +1618,7 @@ pub struct ForeignItem {
     pub vis: Visibility,
 }
 
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum ForeignItem_ {
     ForeignItemFn(P<FnDecl>, Generics),
     ForeignItemStatic(P<Ty>, /* is_mutbl */ bool),
@@ -1630,7 +1633,7 @@ impl ForeignItem_ {
     }
 }
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum UnboxedClosureKind {
     FnUnboxedClosureKind,
     FnMutUnboxedClosureKind,
@@ -1640,7 +1643,7 @@ pub enum UnboxedClosureKind {
 /// The data we save and restore about an inlined item or method.  This is not
 /// part of the AST that we parse from a file, but it becomes part of the tree
 /// that we trans.
-#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub enum InlinedItem {
     IIItem(P<Item>),
     IITraitItem(DefId /* impl id */, TraitItem),
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 02771809ae6..48d39079c5b 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -343,7 +343,7 @@ pub fn empty_generics() -> Generics {
 // ______________________________________________________________________
 // Enumerating the IDs which appear in an AST
 
-#[deriving(Copy, Encodable, Decodable, Show)]
+#[deriving(RustcEncodable, RustcDecodable, Show, Copy)]
 pub struct IdRange {
     pub min: NodeId,
     pub max: NodeId,
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index 127cc5ed51d..cddf1a9923a 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -340,14 +340,14 @@ pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::Me
 }
 
 /// Represents the #[deprecated="foo"] and friends attributes.
-#[deriving(Encodable,Decodable,Clone,Show)]
+#[deriving(RustcEncodable,RustcDecodable,Clone,Show)]
 pub struct Stability {
     pub level: StabilityLevel,
     pub text: Option<InternedString>
 }
 
 /// The available stability levels.
-#[deriving(Copy,Encodable,Decodable,PartialEq,PartialOrd,Clone,Show)]
+#[deriving(RustcEncodable,RustcDecodable,PartialEq,PartialOrd,Clone,Show,Copy)]
 pub enum StabilityLevel {
     Deprecated,
     Experimental,
@@ -464,7 +464,7 @@ fn int_type_of_word(s: &str) -> Option<IntType> {
     }
 }
 
-#[deriving(Copy, PartialEq, Show, Encodable, Decodable)]
+#[deriving(PartialEq, Show, RustcEncodable, RustcDecodable, Copy)]
 pub enum ReprAttr {
     ReprAny,
     ReprInt(Span, IntType),
@@ -483,7 +483,7 @@ impl ReprAttr {
     }
 }
 
-#[deriving(Copy, Eq, Hash, PartialEq, Show, Encodable, Decodable)]
+#[deriving(Eq, Hash, PartialEq, Show, RustcEncodable, RustcDecodable, Copy)]
 pub enum IntType {
     SignedInt(ast::IntTy),
     UnsignedInt(ast::UintTy)
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index c726e17a8fa..221c4fca586 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -92,7 +92,7 @@ pub struct Span {
 
 pub const DUMMY_SP: Span = Span { lo: BytePos(0), hi: BytePos(0), expn_id: NO_EXPANSION };
 
-#[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub struct Spanned<T> {
     pub node: T,
     pub span: Span,
@@ -218,7 +218,7 @@ pub struct ExpnInfo {
     pub callee: NameAndSpan
 }
 
-#[deriving(Copy, PartialEq, Eq, Clone, Show, Hash, Encodable, Decodable)]
+#[deriving(PartialEq, Eq, Clone, Show, Hash, RustcEncodable, RustcDecodable, Copy)]
 pub struct ExpnId(u32);
 
 pub const NO_EXPANSION: ExpnId = ExpnId(-1);
diff --git a/src/libsyntax/ext/deriving/decodable.rs b/src/libsyntax/ext/deriving/decodable.rs
index 0a8d59da896..4878a690bb9 100644
--- a/src/libsyntax/ext/deriving/decodable.rs
+++ b/src/libsyntax/ext/deriving/decodable.rs
@@ -21,6 +21,16 @@ use parse::token::InternedString;
 use parse::token;
 use ptr::P;
 
+pub fn expand_deriving_rustc_decodable<F>(cx: &mut ExtCtxt,
+                                          span: Span,
+                                          mitem: &MetaItem,
+                                          item: &Item,
+                                          push: F) where
+    F: FnOnce(P<Item>),
+{
+    expand_deriving_decodable_imp(cx, span, mitem, item, push, "rustc_serialize")
+}
+
 pub fn expand_deriving_decodable<F>(cx: &mut ExtCtxt,
                                     span: Span,
                                     mitem: &MetaItem,
@@ -28,17 +38,28 @@ pub fn expand_deriving_decodable<F>(cx: &mut ExtCtxt,
                                     push: F) where
     F: FnOnce(P<Item>),
 {
+    expand_deriving_decodable_imp(cx, span, mitem, item, push, "serialize")
+}
+
+fn expand_deriving_decodable_imp<F>(cx: &mut ExtCtxt,
+                                    span: Span,
+                                    mitem: &MetaItem,
+                                    item: &Item,
+                                    push: F,
+                                    krate: &'static str) where
+    F: FnOnce(P<Item>),
+{
     let trait_def = TraitDef {
         span: span,
         attributes: Vec::new(),
-        path: Path::new_(vec!("serialize", "Decodable"), None,
+        path: Path::new_(vec!(krate, "Decodable"), None,
                          vec!(box Literal(Path::new_local("__D")),
                               box Literal(Path::new_local("__E"))), true),
         additional_bounds: Vec::new(),
         generics: LifetimeBounds {
             lifetimes: Vec::new(),
             bounds: vec!(("__D", None, vec!(Path::new_(
-                            vec!("serialize", "Decoder"), None,
+                            vec!(krate, "Decoder"), None,
                             vec!(box Literal(Path::new_local("__E"))), true))),
                          ("__E", None, vec!()))
         },
@@ -54,7 +75,7 @@ pub fn expand_deriving_decodable<F>(cx: &mut ExtCtxt,
                                                box Literal(Path::new_local("__E"))), true)),
                 attributes: Vec::new(),
                 combine_substructure: combine_substructure(|a, b, c| {
-                    decodable_substructure(a, b, c)
+                    decodable_substructure(a, b, c, krate)
                 }),
             })
     };
@@ -63,9 +84,10 @@ pub fn expand_deriving_decodable<F>(cx: &mut ExtCtxt,
 }
 
 fn decodable_substructure(cx: &mut ExtCtxt, trait_span: Span,
-                          substr: &Substructure) -> P<Expr> {
+                          substr: &Substructure,
+                          krate: &str) -> P<Expr> {
     let decoder = substr.nonself_args[0].clone();
-    let recurse = vec!(cx.ident_of("serialize"),
+    let recurse = vec!(cx.ident_of(krate),
                     cx.ident_of("Decodable"),
                     cx.ident_of("decode"));
     // throw an underscore in front to suppress unused variable warnings
diff --git a/src/libsyntax/ext/deriving/encodable.rs b/src/libsyntax/ext/deriving/encodable.rs
index 30851ebeaae..1b8d01f1cd0 100644
--- a/src/libsyntax/ext/deriving/encodable.rs
+++ b/src/libsyntax/ext/deriving/encodable.rs
@@ -97,6 +97,16 @@ use ext::deriving::generic::ty::*;
 use parse::token;
 use ptr::P;
 
+pub fn expand_deriving_rustc_encodable<F>(cx: &mut ExtCtxt,
+                                          span: Span,
+                                          mitem: &MetaItem,
+                                          item: &Item,
+                                          push: F) where
+    F: FnOnce(P<Item>),
+{
+    expand_deriving_encodable_imp(cx, span, mitem, item, push, "rustc_serialize")
+}
+
 pub fn expand_deriving_encodable<F>(cx: &mut ExtCtxt,
                                     span: Span,
                                     mitem: &MetaItem,
@@ -104,17 +114,28 @@ pub fn expand_deriving_encodable<F>(cx: &mut ExtCtxt,
                                     push: F) where
     F: FnOnce(P<Item>),
 {
+    expand_deriving_encodable_imp(cx, span, mitem, item, push, "serialize")
+}
+
+fn expand_deriving_encodable_imp<F>(cx: &mut ExtCtxt,
+                                    span: Span,
+                                    mitem: &MetaItem,
+                                    item: &Item,
+                                    push: F,
+                                    krate: &'static str) where
+    F: FnOnce(P<Item>),
+{
     let trait_def = TraitDef {
         span: span,
         attributes: Vec::new(),
-        path: Path::new_(vec!("serialize", "Encodable"), None,
+        path: Path::new_(vec!(krate, "Encodable"), None,
                          vec!(box Literal(Path::new_local("__S")),
                               box Literal(Path::new_local("__E"))), true),
         additional_bounds: Vec::new(),
         generics: LifetimeBounds {
             lifetimes: Vec::new(),
             bounds: vec!(("__S", None, vec!(Path::new_(
-                            vec!("serialize", "Encoder"), None,
+                            vec!(krate, "Encoder"), None,
                             vec!(box Literal(Path::new_local("__E"))), true))),
                          ("__E", None, vec!()))
         },
diff --git a/src/libsyntax/ext/deriving/mod.rs b/src/libsyntax/ext/deriving/mod.rs
index 839e99c81d1..b5957fd1b8a 100644
--- a/src/libsyntax/ext/deriving/mod.rs
+++ b/src/libsyntax/ext/deriving/mod.rs
@@ -71,24 +71,22 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
                             "Hash" => expand!(hash::expand_deriving_hash),
 
                             "RustcEncodable" => {
-                                expand!(encodable::expand_deriving_encodable)
+                                expand!(encodable::expand_deriving_rustc_encodable)
                             }
                             "RustcDecodable" => {
-                                expand!(decodable::expand_deriving_decodable)
+                                expand!(decodable::expand_deriving_rustc_decodable)
                             }
                             "Encodable" => {
-                                // NOTE: uncomment after a stage0 snap
-                                // cx.span_warn(titem.span,
-                                //              "deriving(Encodable) is deprecated \
-                                //               in favor of deriving(RustcEncodable)");
+                                cx.span_warn(titem.span,
+                                             "deriving(Encodable) is deprecated \
+                                              in favor of deriving(RustcEncodable)");
 
                                 expand!(encodable::expand_deriving_encodable)
                             }
                             "Decodable" => {
-                                // NOTE: uncomment after a stage0 snap
-                                // cx.span_warn(titem.span,
-                                //              "deriving(Decodable) is deprecated \
-                                //               in favor of deriving(RustcDecodable)");
+                                cx.span_warn(titem.span,
+                                             "deriving(Decodable) is deprecated \
+                                              in favor of deriving(RustcDecodable)");
 
                                 expand!(decodable::expand_deriving_decodable)
                             }
diff --git a/src/libsyntax/ext/mtwt.rs b/src/libsyntax/ext/mtwt.rs
index f0392912878..6a296333fdb 100644
--- a/src/libsyntax/ext/mtwt.rs
+++ b/src/libsyntax/ext/mtwt.rs
@@ -39,7 +39,7 @@ pub struct SCTable {
     rename_memo: RefCell<HashMap<(SyntaxContext,Ident,Name),SyntaxContext>>,
 }
 
-#[deriving(Copy, PartialEq, Encodable, Decodable, Hash, Show)]
+#[deriving(PartialEq, RustcEncodable, RustcDecodable, Hash, Show, Copy)]
 pub enum SyntaxContext_ {
     EmptyCtxt,
     Mark (Mrk,SyntaxContext),
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 5f62c74ef07..d5093c5055c 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -34,6 +34,8 @@ extern crate serialize;
 extern crate term;
 extern crate libc;
 
+extern crate "serialize" as rustc_serialize; // used by deriving
+
 pub mod util {
     pub mod interner;
     #[cfg(test)]
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index dad369792d7..87d65e258de 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -28,7 +28,7 @@ use std::path::BytesContainer;
 use std::rc::Rc;
 
 #[allow(non_camel_case_types)]
-#[deriving(Clone, Copy, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
 pub enum BinOpToken {
     Plus,
     Minus,
@@ -43,7 +43,7 @@ pub enum BinOpToken {
 }
 
 /// A delimeter token
-#[deriving(Clone, Copy, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
 pub enum DelimToken {
     /// A round parenthesis: `(` or `)`
     Paren,
@@ -53,14 +53,14 @@ pub enum DelimToken {
     Brace,
 }
 
-#[deriving(Clone, Copy, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
 pub enum IdentStyle {
     /// `::` follows the identifier with no whitespace in-between.
     ModName,
     Plain,
 }
 
-#[deriving(Clone, Copy, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
 pub enum Lit {
     Byte(ast::Name),
     Char(ast::Name),
@@ -86,7 +86,7 @@ impl Lit {
 }
 
 #[allow(non_camel_case_types)]
-#[deriving(Clone, Encodable, Decodable, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show)]
 pub enum Token {
     /* Expression-operator symbols. */
     Eq,
@@ -334,7 +334,7 @@ impl Token {
     }
 }
 
-#[deriving(Clone, Encodable, Decodable, PartialEq, Eq, Hash)]
+#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash)]
 /// For interpolation during macro expansion.
 pub enum Nonterminal {
     NtItem(P<ast::Item>),