std: rewrite Hash to make it more generic

This patch merges IterBytes and Hash traits, which clears up the
confusion of using `#[deriving(IterBytes)]` to support hashing.
Instead, it now is much easier to use the new `#[deriving(Hash)]`
for making a type hashable with a stream hash.

Furthermore, it supports custom non-stream-based hashers, such as
if a value's hash was cached in a database.

This does not yet replace the old IterBytes-hash with this new
version.

25 files changed, 1154 insertions, 15 deletions

diff --git a/src/etc/generate-deriving-span-tests.py b/src/etc/generate-deriving-span-tests.py
index ecf58d55576..cf895d2b6de 100755
--- a/src/etc/generate-deriving-span-tests.py
+++ b/src/etc/generate-deriving-span-tests.py
@@ -119,7 +119,8 @@ for (trait, supers, errs) in [('Rand', [], 1),
                               ('Clone', [], 1), ('DeepClone', ['Clone'], 1),
                               ('Eq', [], 2), ('Ord', [], 8),
                               ('TotalEq', [], 1), ('TotalOrd', ['TotalEq'], 1),
-                              ('Show', [], 1)]:
+                              ('Show', [], 1),
+                              ('Hash', [], 1)]:
     traits[trait] = (ALL, supers, errs)
 
 for (trait, (types, super_traits, error_count)) in traits.items():
diff --git a/src/libextra/stats.rs b/src/libextra/stats.rs
index 181ea6766c5..6738275c4c1 100644
--- a/src/libextra/stats.rs
+++ b/src/libextra/stats.rs
@@ -11,6 +11,7 @@
 #[allow(missing_doc)];
 
 use std::cmp;
+use std::hash_old::Hash;
 use std::hashmap;
 use std::io;
 use std::mem;
diff --git a/src/librustc/metadata/decoder.rs b/src/librustc/metadata/decoder.rs
index 47fcc453489..88aff133fb0 100644
--- a/src/librustc/metadata/decoder.rs
+++ b/src/librustc/metadata/decoder.rs
@@ -27,6 +27,7 @@ use middle::typeck;
 use middle::astencode::vtable_decoder_helpers;
 
 use std::u64;
+use std::hash_old::Hash;
 use std::io;
 use std::io::extensions::u64_from_be_bytes;
 use std::option;
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index d2b843cdcf7..7b7f45b2d2d 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -26,6 +26,7 @@ use middle;
 use serialize::Encodable;
 use std::cast;
 use std::cell::{Cell, RefCell};
+use std::hash_old::Hash;
 use std::hashmap::{HashMap, HashSet};
 use std::io::MemWriter;
 use std::str;
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 09c21d54c87..f47c2f84e99 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -4916,7 +4916,7 @@ pub fn trait_method_of_method(tcx: ctxt,
 /// Creates a hash of the type `t` which will be the same no matter what crate
 /// context it's calculated within. This is used by the `type_id` intrinsic.
 pub fn hash_crate_independent(tcx: ctxt, t: t, local_hash: ~str) -> u64 {
-    use std::hash::{SipState, Streaming};
+    use std::hash_old::{SipState, Streaming};
 
     let mut hash = SipState::new(0, 0);
     let region = |_hash: &mut SipState, r: Region| {
diff --git a/src/libserialize/serialize.rs b/src/libserialize/serialize.rs
index e57e7adcf8d..f350bb0761f 100644
--- a/src/libserialize/serialize.rs
+++ b/src/libserialize/serialize.rs
@@ -14,6 +14,7 @@
 Core encoding and decoding interfaces.
 */
 
+use std::hash_old::Hash;
 use std::hashmap::{HashMap, HashSet};
 use std::rc::Rc;
 use std::trie::{TrieMap, TrieSet};
diff --git a/src/libstd/hash/mod.rs b/src/libstd/hash/mod.rs
new file mode 100644
index 00000000000..ac079cb3fb3
--- /dev/null
+++ b/src/libstd/hash/mod.rs
@@ -0,0 +1,369 @@
+// Copyright 2012-2014 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.
+
+/*!
+ * Generic hashing support.
+ *
+ * This module provides a generic way to compute the hash of a value. The
+ * simplest way to make a type hashable is to use `#[deriving(Hash)]`:
+ *
+ * # Example
+ *
+ * ```rust
+ * use std::hash;
+ * use std::hash::Hash;
+ *
+ * #[deriving(Hash)]
+ * struct Person {
+ *     id: uint,
+ *     name: ~str,
+ *     phone: uint,
+ * }
+ *
+ * let person1 = Person { id: 5, name: ~"Janet", phone: 555_666_7777 };
+ * let person2 = Person { id: 5, name: ~"Bob", phone: 555_666_7777 };
+ *
+ * assert!(hash::hash(&person1) != hash::hash(&person2));
+ * ```
+ *
+ * If you need more control over how a value is hashed, you need to implement
+ * the trait `Hash`:
+ *
+ * ```rust
+ * use std::hash;
+ * use std::hash::Hash;
+ * use std::hash::sip::SipState;
+ *
+ * struct Person {
+ *     id: uint,
+ *     name: ~str,
+ *     phone: uint,
+ * }
+ *
+ * impl Hash for Person {
+ *     fn hash(&self, state: &mut SipState) {
+ *         self.id.hash(state);
+ *         self.phone.hash(state);
+ *     }
+ * }
+ *
+ * let person1 = Person { id: 5, name: ~"Janet", phone: 555_666_7777 };
+ * let person2 = Person { id: 5, name: ~"Bob", phone: 555_666_7777 };
+ *
+ * assert!(hash::hash(&person1) == hash::hash(&person2));
+ * ```
+ */
+
+#[allow(unused_must_use)];
+
+use container::Container;
+use io::Writer;
+use iter::Iterator;
+use option::{Option, Some, None};
+use rc::Rc;
+use str::{Str, StrSlice};
+use vec::{Vector, ImmutableVector};
+
+/// Reexport the `sip::hash` function as our default hasher.
+pub use hash = self::sip::hash;
+
+pub mod sip;
+
+/// A trait that represents a hashable type. The `S` type parameter is an
+/// abstract hash state that is used by the `Hash` to compute the hash.
+/// It defaults to `std::hash::sip::SipState`.
+pub trait Hash<S = sip::SipState> {
+    /// Compute a hash of the value.
+    fn hash(&self, state: &mut S);
+}
+
+/// A trait that computes a hash for a value. The main users of this trait are
+/// containers like `HashMap`, which need a generic way hash multiple types.
+pub trait Hasher<S> {
+    /// Compute a hash of the value.
+    fn hash<T: Hash<S>>(&self, value: &T) -> u64;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+macro_rules! impl_hash(
+    ( $( $ty:ty => $method:ident;)* ) => (
+        $(
+            impl<S: Writer> Hash<S> for $ty {
+                #[inline]
+                fn hash(&self, state: &mut S) {
+                    state.$method(*self);
+                }
+            }
+        )*
+    )
+)
+
+impl_hash!(
+    u8 => write_u8;
+    u16 => write_le_u16;
+    u32 => write_le_u32;
+    u64 => write_le_u64;
+    uint => write_le_uint;
+    i8 => write_i8;
+    i16 => write_le_i16;
+    i32 => write_le_i32;
+    i64 => write_le_i64;
+    int => write_le_int;
+)
+
+impl<S: Writer> Hash<S> for bool {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (*self as u8).hash(state);
+    }
+}
+
+impl<S: Writer> Hash<S> for char {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (*self as u32).hash(state);
+    }
+}
+
+impl<'a, S: Writer> Hash<S> for &'a str {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        state.write(self.as_bytes());
+        state.write_u8(0xFF);
+    }
+}
+
+impl<S: Writer> Hash<S> for ~str {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        self.as_slice().hash(state);
+    }
+}
+
+macro_rules! impl_hash_tuple(
+    () => (
+        impl<S: Writer> Hash<S> for () {
+            #[inline]
+            fn hash(&self, state: &mut S) {
+                state.write([]);
+            }
+        }
+    );
+
+    ($A:ident $($B:ident)*) => (
+        impl<
+            S: Writer,
+            $A: Hash<S> $(, $B: Hash<S>)*
+        > Hash<S> for ($A, $($B),*) {
+            #[inline]
+            fn hash(&self, state: &mut S) {
+                match *self {
+                    (ref $A, $(ref $B),*) => {
+                        $A.hash(state);
+                        $(
+                            $B.hash(state);
+                        )*
+                    }
+                }
+            }
+        }
+
+        impl_hash_tuple!($($B)*)
+    );
+)
+
+impl_hash_tuple!(A0 A1 A2 A3 A4 A5 A6 A7)
+
+impl<'a, S: Writer, T: Hash<S>> Hash<S> for &'a [T] {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        self.len().hash(state);
+        for elt in self.iter() {
+            elt.hash(state);
+        }
+    }
+}
+
+
+impl<'a, S: Writer, T: Hash<S>> Hash<S> for &'a mut [T] {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        self.as_slice().hash(state);
+    }
+}
+
+impl<S: Writer, T: Hash<S>> Hash<S> for ~[T] {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        self.as_slice().hash(state);
+    }
+}
+
+impl<'a, S: Writer, T: Hash<S>> Hash<S> for &'a T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
+impl<'a, S: Writer, T: Hash<S>> Hash<S> for &'a mut T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
+impl<S: Writer, T: Hash<S>> Hash<S> for ~T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
+impl<S: Writer, T: Hash<S>> Hash<S> for @T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
+impl<S: Writer, T: Hash<S>> Hash<S> for Rc<T> {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        self.borrow().hash(state);
+    }
+}
+
+impl<S: Writer, T: Hash<S>> Hash<S> for Option<T> {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        match *self {
+            Some(ref x) => {
+                0u8.hash(state);
+                x.hash(state);
+            }
+            None => {
+                1u8.hash(state);
+            }
+        }
+    }
+}
+
+impl<S: Writer, T> Hash<S> for *T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        // NB: raw-pointer Hash does _not_ dereference
+        // to the target; it just gives you the pointer-bytes.
+        (*self as uint).hash(state);
+    }
+}
+
+impl<S: Writer, T> Hash<S> for *mut T {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        // NB: raw-pointer Hash does _not_ dereference
+        // to the target; it just gives you the pointer-bytes.
+        (*self as uint).hash(state);
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#[cfg(test)]
+mod tests {
+    use cast;
+    use io::{IoResult, Writer};
+    use iter::{Iterator};
+    use option::{Some, None};
+    use result::Ok;
+    use vec::ImmutableVector;
+
+    use super::{Hash, Hasher};
+
+    struct MyWriterHasher;
+
+    impl Hasher<MyWriter> for MyWriterHasher {
+        fn hash<T: Hash<MyWriter>>(&self, value: &T) -> u64 {
+            let mut state = MyWriter { hash: 0 };
+            value.hash(&mut state);
+            state.hash
+        }
+    }
+
+    struct MyWriter {
+        hash: u64,
+    }
+
+    impl Writer for MyWriter {
+        // Most things we'll just add up the bytes.
+        fn write(&mut self, buf: &[u8]) -> IoResult<()> {
+            for byte in buf.iter() {
+                self.hash += *byte as u64;
+            }
+            Ok(())
+        }
+    }
+
+    #[test]
+    fn test_writer_hasher() {
+        let hasher = MyWriterHasher;
+
+        assert_eq!(hasher.hash(&()), 0);
+
+        assert_eq!(hasher.hash(&5u8), 5);
+        assert_eq!(hasher.hash(&5u16), 5);
+        assert_eq!(hasher.hash(&5u32), 5);
+        assert_eq!(hasher.hash(&5u64), 5);
+        assert_eq!(hasher.hash(&5u), 5);
+
+        assert_eq!(hasher.hash(&5i8), 5);
+        assert_eq!(hasher.hash(&5i16), 5);
+        assert_eq!(hasher.hash(&5i32), 5);
+        assert_eq!(hasher.hash(&5i64), 5);
+        assert_eq!(hasher.hash(&5i), 5);
+
+        assert_eq!(hasher.hash(&false), 0);
+        assert_eq!(hasher.hash(&true), 1);
+
+        assert_eq!(hasher.hash(&'a'), 97);
+
+        assert_eq!(hasher.hash(& &"a"), 97 + 0xFF);
+        assert_eq!(hasher.hash(& &[1u8, 2u8, 3u8]), 9);
+
+        unsafe {
+            let ptr: *int = cast::transmute(5);
+            assert_eq!(hasher.hash(&ptr), 5);
+        }
+
+        unsafe {
+            let ptr: *mut int = cast::transmute(5);
+            assert_eq!(hasher.hash(&ptr), 5);
+        }
+    }
+
+    struct Custom {
+        hash: u64
+    }
+
+    impl Hash<u64> for Custom {
+        fn hash(&self, state: &mut u64) {
+            *state = self.hash;
+        }
+    }
+
+    #[test]
+    fn test_custom_state() {
+        let custom = Custom { hash: 5 };
+        let mut state = 0;
+        custom.hash(&mut state);
+        assert_eq!(state, 5);
+    }
+}
diff --git a/src/libstd/hash/sip.rs b/src/libstd/hash/sip.rs
new file mode 100644
index 00000000000..ce5e0d6b2ed
--- /dev/null
+++ b/src/libstd/hash/sip.rs
@@ -0,0 +1,519 @@
+// Copyright 2012-2014 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.
+
+/*!
+ * Implementation of SipHash 2-4
+ *
+ * See: http://131002.net/siphash/
+ *
+ * Consider this as a main "general-purpose" hash for all hashtables: it
+ * runs at good speed (competitive with spooky and city) and permits
+ * strong _keyed_ hashing. Key your hashtables from a strong RNG,
+ * such as `rand::Rng`.
+ *
+ * Although the SipHash algorithm is considered to be cryptographically
+ * strong, this implementation has not been reviewed for such purposes.
+ * As such, all cryptographic uses of this implementation are strongly
+ * discouraged.
+ */
+
+use container::Container;
+use io::{IoResult, Writer};
+use iter::Iterator;
+use result::Ok;
+use vec::ImmutableVector;
+
+use super::{Hash, Hasher};
+
+/// `SipState` computes a SipHash 2-4 hash over a stream of bytes.
+pub struct SipState {
+    priv k0: u64,
+    priv k1: u64,
+    priv length: uint, // how many bytes we've processed
+    priv v0: u64,      // hash state
+    priv v1: u64,
+    priv v2: u64,
+    priv v3: u64,
+    priv tail: [u8, ..8], // unprocessed bytes
+    priv ntail: uint,  // how many bytes in tail are valid
+}
+
+// sadly, these macro definitions can't appear later,
+// because they're needed in the following defs;
+// this design could be improved.
+
+macro_rules! u8to64_le (
+    ($buf:expr, $i:expr) =>
+    ($buf[0+$i] as u64 |
+     $buf[1+$i] as u64 << 8 |
+     $buf[2+$i] as u64 << 16 |
+     $buf[3+$i] as u64 << 24 |
+     $buf[4+$i] as u64 << 32 |
+     $buf[5+$i] as u64 << 40 |
+     $buf[6+$i] as u64 << 48 |
+     $buf[7+$i] as u64 << 56)
+)
+
+macro_rules! rotl (
+    ($x:expr, $b:expr) =>
+    (($x << $b) | ($x >> (64 - $b)))
+)
+
+macro_rules! compress (
+    ($v0:expr, $v1:expr, $v2:expr, $v3:expr) =>
+    ({
+        $v0 += $v1; $v1 = rotl!($v1, 13); $v1 ^= $v0;
+        $v0 = rotl!($v0, 32);
+        $v2 += $v3; $v3 = rotl!($v3, 16); $v3 ^= $v2;
+        $v0 += $v3; $v3 = rotl!($v3, 21); $v3 ^= $v0;
+        $v2 += $v1; $v1 = rotl!($v1, 17); $v1 ^= $v2;
+        $v2 = rotl!($v2, 32);
+    })
+)
+
+impl SipState {
+    /// Create a `SipState` that is keyed off the provided keys.
+    #[inline]
+    pub fn new(key0: u64, key1: u64) -> SipState {
+        let mut state = SipState {
+            k0: key0,
+            k1: key1,
+            length: 0,
+            v0: 0,
+            v1: 0,
+            v2: 0,
+            v3: 0,
+            tail: [ 0, 0, 0, 0, 0, 0, 0, 0 ],
+            ntail: 0,
+        };
+        state.reset();
+        state
+    }
+
+    /// Reset the state back to it's initial state.
+    #[inline]
+    pub fn reset(&mut self) {
+        self.length = 0;
+        self.v0 = self.k0 ^ 0x736f6d6570736575;
+        self.v1 = self.k1 ^ 0x646f72616e646f6d;
+        self.v2 = self.k0 ^ 0x6c7967656e657261;
+        self.v3 = self.k1 ^ 0x7465646279746573;
+        self.ntail = 0;
+    }
+
+    /// Return the computed hash.
+    #[inline]
+    pub fn result(&self) -> u64 {
+        let mut v0 = self.v0;
+        let mut v1 = self.v1;
+        let mut v2 = self.v2;
+        let mut v3 = self.v3;
+
+        let mut b : u64 = (self.length as u64 & 0xff) << 56;
+
+        if self.ntail > 0 { b |= self.tail[0] as u64 <<  0; }
+        if self.ntail > 1 { b |= self.tail[1] as u64 <<  8; }
+        if self.ntail > 2 { b |= self.tail[2] as u64 << 16; }
+        if self.ntail > 3 { b |= self.tail[3] as u64 << 24; }
+        if self.ntail > 4 { b |= self.tail[4] as u64 << 32; }
+        if self.ntail > 5 { b |= self.tail[5] as u64 << 40; }
+        if self.ntail > 6 { b |= self.tail[6] as u64 << 48; }
+
+        v3 ^= b;
+        compress!(v0, v1, v2, v3);
+        compress!(v0, v1, v2, v3);
+        v0 ^= b;
+
+        v2 ^= 0xff;
+        compress!(v0, v1, v2, v3);
+        compress!(v0, v1, v2, v3);
+        compress!(v0, v1, v2, v3);
+        compress!(v0, v1, v2, v3);
+
+        v0 ^ v1 ^ v2 ^ v3
+    }
+}
+
+impl Writer for SipState {
+    #[inline]
+    fn write(&mut self, msg: &[u8]) -> IoResult<()> {
+        let length = msg.len();
+        self.length += length;
+
+        let mut needed = 0u;
+
+        if self.ntail != 0 {
+            needed = 8 - self.ntail;
+
+            if length < needed {
+                let mut t = 0;
+                while t < length {
+                    self.tail[self.ntail+t] = msg[t];
+                    t += 1;
+                }
+                self.ntail += length;
+                return Ok(());
+            }
+
+            let mut t = 0;
+            while t < needed {
+                self.tail[self.ntail+t] = msg[t];
+                t += 1;
+            }
+
+            let m = u8to64_le!(self.tail, 0);
+
+            self.v3 ^= m;
+            compress!(self.v0, self.v1, self.v2, self.v3);
+            compress!(self.v0, self.v1, self.v2, self.v3);
+            self.v0 ^= m;
+
+            self.ntail = 0;
+        }
+
+        // Buffered tail is now flushed, process new input.
+        let len = length - needed;
+        let end = len & (!0x7);
+        let left = len & 0x7;
+
+        let mut i = needed;
+        while i < end {
+            let mi = u8to64_le!(msg, i);
+
+            self.v3 ^= mi;
+            compress!(self.v0, self.v1, self.v2, self.v3);
+            compress!(self.v0, self.v1, self.v2, self.v3);
+            self.v0 ^= mi;
+
+            i += 8;
+        }
+
+        let mut t = 0u;
+        while t < left {
+            self.tail[t] = msg[i+t];
+            t += 1
+        }
+        self.ntail = left;
+
+        Ok(())
+    }
+}
+
+/// `Sip` computes the SipHash algorithm from a stream of bytes.
+pub struct SipHasher {
+    priv state: SipState,
+}
+
+impl SipHasher {
+    /// Create a `Sip`.
+    #[inline]
+    pub fn new() -> SipHasher {
+        SipHasher::new_with_keys(0, 0)
+    }
+
+    /// Create a `Sip` that is keyed off the provided keys.
+    #[inline]
+    pub fn new_with_keys(key0: u64, key1: u64) -> SipHasher {
+        SipHasher {
+            state: SipState::new(key0, key1),
+        }
+    }
+}
+
+impl Hasher<SipState> for SipHasher {
+    #[inline]
+    fn hash<T: Hash<SipState>>(&self, value: &T) -> u64 {
+        let mut state = self.state; // implicitly copy the state.
+        value.hash(&mut state);
+        state.result()
+    }
+}
+
+
+/// Hash a value using the SipHash algorithm.
+#[inline]
+pub fn hash<T: Hash<SipState>>(value: &T) -> u64 {
+    hash_with_keys(0, 0, value)
+}
+
+/// Hash a value with the SipHash algorithm with the provided keys.
+#[inline]
+pub fn hash_with_keys<T: Hash<SipState>>(k0: u64, k1: u64, value: &T) -> u64 {
+    let mut state = SipState::new(k0, k1);
+    value.hash(&mut state);
+    state.result()
+}
+
+#[cfg(test)]
+mod tests {
+    extern crate test;
+    use io::Writer;
+    use iter::Iterator;
+    use num::ToStrRadix;
+    use option::{Some, None};
+    use str::{Str, OwnedStr};
+    use vec::{Vector, ImmutableVector, OwnedVector};
+    use self::test::BenchHarness;
+
+    use super::super::Hash;
+    use super::{SipState, hash, hash_with_keys};
+
+    // Hash just the bytes of the slice, without length prefix
+    struct Bytes<'a>(&'a [u8]);
+
+    impl<'a, S: Writer> Hash<S> for Bytes<'a> {
+        #[allow(unused_must_use)]
+        fn hash(&self, state: &mut S) {
+            let Bytes(v) = *self;
+            state.write(v);
+        }
+    }
+
+    #[test]
+    #[allow(unused_must_use)]
+    fn test_siphash() {
+        let vecs : [[u8, ..8], ..64] = [
+            [ 0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72, ],
+            [ 0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74, ],
+            [ 0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d, ],
+            [ 0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85, ],
+            [ 0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf, ],
+            [ 0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18, ],
+            [ 0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb, ],
+            [ 0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab, ],
+            [ 0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93, ],
+            [ 0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e, ],
+            [ 0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a, ],
+            [ 0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4, ],
+            [ 0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75, ],
+            [ 0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14, ],
+            [ 0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7, ],
+            [ 0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1, ],
+            [ 0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f, ],
+            [ 0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69, ],
+            [ 0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b, ],
+            [ 0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb, ],
+            [ 0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe, ],
+            [ 0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0, ],
+            [ 0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93, ],
+            [ 0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8, ],
+            [ 0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8, ],
+            [ 0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc, ],
+            [ 0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17, ],
+            [ 0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f, ],
+            [ 0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde, ],
+            [ 0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6, ],
+            [ 0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad, ],
+            [ 0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32, ],
+            [ 0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71, ],
+            [ 0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7, ],
+            [ 0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12, ],
+            [ 0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15, ],
+            [ 0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31, ],
+            [ 0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02, ],
+            [ 0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca, ],
+            [ 0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a, ],
+            [ 0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e, ],
+            [ 0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad, ],
+            [ 0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18, ],
+            [ 0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4, ],
+            [ 0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9, ],
+            [ 0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9, ],
+            [ 0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb, ],
+            [ 0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0, ],
+            [ 0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6, ],
+            [ 0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7, ],
+            [ 0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee, ],
+            [ 0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1, ],
+            [ 0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a, ],
+            [ 0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81, ],
+            [ 0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f, ],
+            [ 0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24, ],
+            [ 0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7, ],
+            [ 0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea, ],
+            [ 0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60, ],
+            [ 0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66, ],
+            [ 0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c, ],
+            [ 0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f, ],
+            [ 0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5, ],
+            [ 0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95, ]
+        ];
+
+        let k0 = 0x_07_06_05_04_03_02_01_00_u64;
+        let k1 = 0x_0f_0e_0d_0c_0b_0a_09_08_u64;
+        let mut buf : ~[u8] = ~[];
+        let mut t = 0;
+        let mut state_inc = SipState::new(k0, k1);
+        let mut state_full = SipState::new(k0, k1);
+
+        fn to_hex_str(r: &[u8, ..8]) -> ~str {
+            let mut s = ~"";
+            for b in r.iter() {
+                s.push_str((*b as uint).to_str_radix(16u));
+            }
+            s
+        }
+
+        fn result_bytes(h: u64) -> ~[u8] {
+            ~[(h >> 0) as u8,
+              (h >> 8) as u8,
+              (h >> 16) as u8,
+              (h >> 24) as u8,
+              (h >> 32) as u8,
+              (h >> 40) as u8,
+              (h >> 48) as u8,
+              (h >> 56) as u8,
+            ]
+        }
+
+        fn result_str(h: u64) -> ~str {
+            let r = result_bytes(h);
+            let mut s = ~"";
+            for b in r.iter() {
+                s.push_str((*b as uint).to_str_radix(16u));
+            }
+            s
+        }
+
+        while t < 64 {
+            debug!("siphash test {}", t);
+            let vec = u8to64_le!(vecs[t], 0);
+            let out = hash_with_keys(k0, k1, &Bytes(buf.as_slice()));
+            debug!("got {:?}, expected {:?}", out, vec);
+            assert_eq!(vec, out);
+
+            state_full.reset();
+            state_full.write(buf);
+            let f = result_str(state_full.result());
+            let i = result_str(state_inc.result());
+            let v = to_hex_str(&vecs[t]);
+            debug!("{}: ({}) => inc={} full={}", t, v, i, f);
+
+            assert!(f == i && f == v);
+
+            buf.push(t as u8);
+            state_inc.write_u8(t);
+
+            t += 1;
+        }
+    }
+
+    #[test] #[cfg(target_arch = "arm")]
+    fn test_hash_uint() {
+        let val = 0xdeadbeef_deadbeef_u64;
+        assert!(hash(&(val as u64)) != hash(&(val as uint)));
+        assert_eq!(hash(&(val as u32)), hash(&(val as uint)));
+    }
+    #[test] #[cfg(target_arch = "x86_64")]
+    fn test_hash_uint() {
+        let val = 0xdeadbeef_deadbeef_u64;
+        assert_eq!(hash(&(val as u64)), hash(&(val as uint)));
+        assert!(hash(&(val as u32)) != hash(&(val as uint)));
+    }
+    #[test] #[cfg(target_arch = "x86")]
+    fn test_hash_uint() {
+        let val = 0xdeadbeef_deadbeef_u64;
+        assert!(hash(&(val as u64)) != hash(&(val as uint)));
+        assert_eq!(hash(&(val as u32)), hash(&(val as uint)));
+    }
+
+    #[test]
+    fn test_hash_idempotent() {
+        let val64 = 0xdeadbeef_deadbeef_u64;
+        assert_eq!(hash(&val64), hash(&val64));
+        let val32 = 0xdeadbeef_u32;
+        assert_eq!(hash(&val32), hash(&val32));
+    }
+
+    #[test]
+    fn test_hash_no_bytes_dropped_64() {
+        let val = 0xdeadbeef_deadbeef_u64;
+
+        assert!(hash(&val) != hash(&zero_byte(val, 0)));
+        assert!(hash(&val) != hash(&zero_byte(val, 1)));
+        assert!(hash(&val) != hash(&zero_byte(val, 2)));
+        assert!(hash(&val) != hash(&zero_byte(val, 3)));
+        assert!(hash(&val) != hash(&zero_byte(val, 4)));
+        assert!(hash(&val) != hash(&zero_byte(val, 5)));
+        assert!(hash(&val) != hash(&zero_byte(val, 6)));
+        assert!(hash(&val) != hash(&zero_byte(val, 7)));
+
+        fn zero_byte(val: u64, byte: uint) -> u64 {
+            assert!(byte < 8);
+            val & !(0xff << (byte * 8))
+        }
+    }
+
+    #[test]
+    fn test_hash_no_bytes_dropped_32() {
+        let val = 0xdeadbeef_u32;
+
+        assert!(hash(&val) != hash(&zero_byte(val, 0)));
+        assert!(hash(&val) != hash(&zero_byte(val, 1)));
+        assert!(hash(&val) != hash(&zero_byte(val, 2)));
+        assert!(hash(&val) != hash(&zero_byte(val, 3)));
+
+        fn zero_byte(val: u32, byte: uint) -> u32 {
+            assert!(byte < 4);
+            val & !(0xff << (byte * 8))
+        }
+    }
+
+    #[test]
+    fn test_hash_no_concat_alias() {
+        let s = ("aa", "bb");
+        let t = ("aabb", "");
+        let u = ("a", "abb");
+
+        assert!(s != t && t != u);
+        assert!(hash(&s) != hash(&t) && hash(&s) != hash(&u));
+
+        let v = (&[1u8], &[0u8, 0], &[0u8]);
+        let w = (&[1u8, 0, 0, 0], &[], &[]);
+
+        assert!(v != w);
+        assert!(hash(&v) != hash(&w));
+    }
+
+    #[bench]
+    fn bench_str(bh: &mut BenchHarness) {
+        let s = "foo";
+        bh.iter(|| {
+            assert_eq!(hash(&s), 16262950014981195938);
+        })
+    }
+
+    struct Compound {
+        x: u8,
+        y: u16,
+        z: ~str,
+    }
+
+    impl<S: Writer> Hash<S> for Compound {
+        #[inline]
+        fn hash(&self, state: &mut S) {
+            self.x.hash(state);
+            self.y.hash(state);
+            self.z.hash(state);
+        }
+    }
+
+    #[bench]
+    fn bench_compound_1(bh: &mut BenchHarness) {
+        let compound = Compound {
+            x: 1,
+            y: 2,
+            z: ~"foobarbaz",
+        };
+        bh.iter(|| {
+            assert_eq!(hash(&compound), 3581836382593270478);
+        })
+    }
+}
diff --git a/src/libstd/hash.rs b/src/libstd/hash_old.rs
index 432e27257f3..07b16db95f8 100644
--- a/src/libstd/hash.rs
+++ b/src/libstd/hash_old.rs
@@ -36,7 +36,7 @@ use to_bytes::IterBytes;
 use vec::ImmutableVector;
 
 // Alias `SipState` to `State`.
-pub use State = hash::SipState;
+pub use State = hash_old::SipState;
 
 /**
  * Types that can meaningfully be hashed should implement this.
@@ -298,9 +298,13 @@ impl Streaming for SipState {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use prelude::*;
-    use super::SipState;
+    use super::{Hash, Streaming, SipState};
+    use iter::Iterator;
+    use num::ToStrRadix;
+    use option::Some;
+    use str::OwnedStr;
+    use to_bytes::IterBytes;
+    use vec::{Vector, OwnedVector, ImmutableVector};
 
     // Hash just the bytes of the slice, without length prefix
     struct Bytes<'a>(&'a [u8]);
diff --git a/src/libstd/hashmap.rs b/src/libstd/hashmap.rs
index 5d4db106728..f3783c27b54 100644
--- a/src/libstd/hashmap.rs
+++ b/src/libstd/hashmap.rs
@@ -57,7 +57,7 @@ use clone::Clone;
 use cmp::{Eq, Equiv, max};
 use default::Default;
 use fmt;
-use hash::Hash;
+use hash_old::Hash;
 use iter;
 use iter::{Iterator, FromIterator, Extendable};
 use iter::{FilterMap, Chain, Repeat, Zip};
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index d3ddd9ae783..6996cba42b4 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -54,6 +54,10 @@
 
 #[feature(macro_rules, globs, asm, managed_boxes, thread_local, link_args, simd)];
 
+// Turn on default type parameters.
+#[feature(default_type_params)];
+#[allow(default_type_param_usage)];
+
 // Don't link to std. We are std.
 #[no_std];
 
@@ -141,6 +145,7 @@ pub mod iter;
 pub mod to_str;
 pub mod to_bytes;
 pub mod clone;
+pub mod hash_old;
 pub mod hash;
 pub mod container;
 pub mod default;
@@ -213,6 +218,7 @@ mod std {
     pub use cmp;
     pub use comm;
     pub use fmt;
+    pub use hash;
     pub use io;
     pub use kinds;
     pub use local_data;
diff --git a/src/libstd/prelude.rs b/src/libstd/prelude.rs
index d322650cec9..83ef85fc35b 100644
--- a/src/libstd/prelude.rs
+++ b/src/libstd/prelude.rs
@@ -45,7 +45,6 @@ pub use cmp::{Eq, Ord, TotalEq, TotalOrd, Ordering, Less, Equal, Greater, Equiv}
 pub use container::{Container, Mutable, Map, MutableMap, Set, MutableSet};
 pub use default::Default;
 pub use from_str::FromStr;
-pub use hash::Hash;
 pub use iter::{FromIterator, Extendable};
 pub use iter::{Iterator, DoubleEndedIterator, RandomAccessIterator, CloneableIterator};
 pub use iter::{OrdIterator, MutableDoubleEndedIterator, ExactSize};
diff --git a/src/libstd/to_str.rs b/src/libstd/to_str.rs
index ab14e9f5667..0e5627fa066 100644
--- a/src/libstd/to_str.rs
+++ b/src/libstd/to_str.rs
@@ -18,7 +18,7 @@ use option::{Some, None};
 use str::OwnedStr;
 use hashmap::HashMap;
 use hashmap::HashSet;
-use hash::Hash;
+use hash_old::Hash;
 use iter::Iterator;
 use cmp::Eq;
 use vec::ImmutableVector;
diff --git a/src/libsyntax/ext/deriving/generic.rs b/src/libsyntax/ext/deriving/generic.rs
index a3bef1b5edd..99ac07ba4d7 100644
--- a/src/libsyntax/ext/deriving/generic.rs
+++ b/src/libsyntax/ext/deriving/generic.rs
@@ -416,11 +416,11 @@ impl<'a> TraitDef<'a> {
                           self_type, methods.map(|x| *x)))
     }
 
-    pub fn expand_struct_def(&self,
-                             cx: &mut ExtCtxt,
-                             struct_def: &StructDef,
-                             type_ident: Ident,
-                             generics: &Generics) -> @ast::Item {
+    fn expand_struct_def(&self,
+                         cx: &mut ExtCtxt,
+                         struct_def: &StructDef,
+                         type_ident: Ident,
+                         generics: &Generics) -> @ast::Item {
         let methods = self.methods.map(|method_def| {
             let (explicit_self, self_args, nonself_args, tys) =
                 method_def.split_self_nonself_args(
@@ -450,7 +450,7 @@ impl<'a> TraitDef<'a> {
         self.create_derived_impl(cx, type_ident, generics, methods)
     }
 
-    pub fn expand_enum_def(&self,
+    fn expand_enum_def(&self,
                        cx: &mut ExtCtxt,
                        enum_def: &EnumDef,
                        type_ident: Ident,
diff --git a/src/libsyntax/ext/deriving/hash.rs b/src/libsyntax/ext/deriving/hash.rs
new file mode 100644
index 00000000000..0b9158547ed
--- /dev/null
+++ b/src/libsyntax/ext/deriving/hash.rs
@@ -0,0 +1,97 @@
+// Copyright 2014 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.
+
+use ast::{MetaItem, Item, Expr, MutMutable};
+use codemap::Span;
+use ext::base::ExtCtxt;
+use ext::build::AstBuilder;
+use ext::deriving::generic::*;
+use parse::token::InternedString;
+
+pub fn expand_deriving_hash(cx: &mut ExtCtxt,
+                            span: Span,
+                            mitem: @MetaItem,
+                            item: @Item,
+                            push: |@Item|) {
+
+    let allow_default_type_param_usage = cx.attribute(
+        span,
+        cx.meta_list(
+            span,
+            InternedString::new("allow"),
+            ~[cx.meta_word(span, InternedString::new("default_type_param_usage"))]));
+
+    let hash_trait_def = TraitDef {
+        span: span,
+        attributes: ~[allow_default_type_param_usage],
+        path: Path::new_(~["std", "hash", "Hash"], None,
+                         ~[~Literal(Path::new_local("__H"))], true),
+        additional_bounds: ~[],
+        generics: LifetimeBounds {
+            lifetimes: ~[],
+            bounds: ~[("__H", ~[Path::new(~["std", "io", "Writer"])])],
+        },
+        methods: ~[
+            MethodDef {
+                name: "hash",
+                generics: LifetimeBounds::empty(),
+                explicit_self: borrowed_explicit_self(),
+                args: ~[Ptr(~Literal(Path::new_local("__H")),
+                            Borrowed(None, MutMutable))],
+                ret_ty: nil_ty(),
+                inline: true,
+                const_nonmatching: false,
+                combine_substructure: hash_substructure
+            }
+        ]
+    };
+
+    hash_trait_def.expand(cx, mitem, item, push);
+}
+
+fn hash_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructure) -> @Expr {
+    let state_expr = match substr.nonself_args {
+        [state_expr] => state_expr,
+        _ => cx.span_bug(trait_span, "incorrect number of arguments in `deriving(Hash)`")
+    };
+    let hash_ident = substr.method_ident;
+    let call_hash = |span, thing_expr| {
+        let expr = cx.expr_method_call(span, thing_expr, hash_ident, ~[state_expr]);
+        cx.stmt_expr(expr)
+    };
+    let mut stmts = ~[];
+
+    let fields = match *substr.fields {
+        Struct(ref fs) => fs,
+        EnumMatching(index, variant, ref fs) => {
+            // Determine the discriminant. We will feed this value to the byte
+            // iteration function.
+            let discriminant = match variant.node.disr_expr {
+                Some(d) => d,
+                None => cx.expr_uint(trait_span, index)
+            };
+
+            stmts.push(call_hash(trait_span, discriminant));
+
+            fs
+        }
+        _ => cx.span_bug(trait_span, "impossible substructure in `deriving(Hash)`")
+    };
+
+    for &FieldInfo { self_, span, .. } in fields.iter() {
+        stmts.push(call_hash(span, self_));
+    }
+
+    if stmts.len() == 0 {
+        cx.span_bug(trait_span, "#[deriving(Hash)] needs at least one field");
+    }
+
+    cx.expr_block(cx.block(trait_span, stmts, None))
+}
diff --git a/src/libsyntax/ext/deriving/mod.rs b/src/libsyntax/ext/deriving/mod.rs
index 7c686e5cd67..31ee99fbd26 100644
--- a/src/libsyntax/ext/deriving/mod.rs
+++ b/src/libsyntax/ext/deriving/mod.rs
@@ -26,6 +26,7 @@ pub mod clone;
 pub mod iter_bytes;
 pub mod encodable;
 pub mod decodable;
+pub mod hash;
 pub mod rand;
 pub mod to_str;
 pub mod show;
@@ -74,6 +75,7 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
                             "DeepClone" => expand!(clone::expand_deriving_deep_clone),
 
                             "IterBytes" => expand!(iter_bytes::expand_deriving_iter_bytes),
+                            "Hash" => expand!(hash::expand_deriving_hash),
 
                             "Encodable" => expand!(encodable::expand_deriving_encodable),
                             "Decodable" => expand!(decodable::expand_deriving_decodable),
diff --git a/src/libsyntax/util/interner.rs b/src/libsyntax/util/interner.rs
index aedff2d7854..1c801f7d970 100644
--- a/src/libsyntax/util/interner.rs
+++ b/src/libsyntax/util/interner.rs
@@ -17,6 +17,7 @@ use ast::Name;
 use std::cast;
 use std::cell::RefCell;
 use std::cmp::Equiv;
+use std::hash_old::Hash;
 use std::hashmap::HashMap;
 use std::rc::Rc;
 
diff --git a/src/test/compile-fail/deriving-span-Hash-enum-struct-variant.rs b/src/test/compile-fail/deriving-span-Hash-enum-struct-variant.rs
new file mode 100644
index 00000000000..182c669cbea
--- /dev/null
+++ b/src/test/compile-fail/deriving-span-Hash-enum-struct-variant.rs
@@ -0,0 +1,27 @@
+// Copyright 2014 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 file was auto-generated using 'src/etc/generate-keyword-span-tests.py'
+
+#[feature(struct_variant)];
+extern crate extra;
+
+use std::hash::Hash;
+
+struct Error;
+
+#[deriving(Hash)]
+enum Enum {
+   A {
+     x: Error //~ ERROR
+   }
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/deriving-span-Hash-enum.rs b/src/test/compile-fail/deriving-span-Hash-enum.rs
new file mode 100644
index 00000000000..7617e0a33c3
--- /dev/null
+++ b/src/test/compile-fail/deriving-span-Hash-enum.rs
@@ -0,0 +1,27 @@
+// Copyright 2014 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 file was auto-generated using 'src/etc/generate-keyword-span-tests.py'
+
+#[feature(struct_variant)];
+extern crate extra;
+
+use std::hash::Hash;
+
+struct Error;
+
+#[deriving(Hash)]
+enum Enum {
+   A(
+     Error //~ ERROR
+     )
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/deriving-span-Hash-struct.rs b/src/test/compile-fail/deriving-span-Hash-struct.rs
new file mode 100644
index 00000000000..f20da9a9d16
--- /dev/null
+++ b/src/test/compile-fail/deriving-span-Hash-struct.rs
@@ -0,0 +1,25 @@
+// Copyright 2014 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 file was auto-generated using 'src/etc/generate-keyword-span-tests.py'
+
+#[feature(struct_variant)];
+extern crate extra;
+
+use std::hash::Hash;
+
+struct Error;
+
+#[deriving(Hash)]
+struct Struct {
+    x: Error //~ ERROR
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/deriving-span-Hash-tuple-struct.rs b/src/test/compile-fail/deriving-span-Hash-tuple-struct.rs
new file mode 100644
index 00000000000..9b7ae50b738
--- /dev/null
+++ b/src/test/compile-fail/deriving-span-Hash-tuple-struct.rs
@@ -0,0 +1,25 @@
+// Copyright 2014 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 file was auto-generated using 'src/etc/generate-keyword-span-tests.py'
+
+#[feature(struct_variant)];
+extern crate extra;
+
+use std::hash::Hash;
+
+struct Error;
+
+#[deriving(Hash)]
+struct Struct(
+    Error //~ ERROR
+);
+
+fn main() {}
diff --git a/src/test/run-pass/deriving-hash.rs b/src/test/run-pass/deriving-hash.rs
new file mode 100644
index 00000000000..087b7ce56ab
--- /dev/null
+++ b/src/test/run-pass/deriving-hash.rs
@@ -0,0 +1,28 @@
+// Copyright 2014 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-fast
+
+use std::hash;
+use std::hash::Hash;
+
+#[deriving(Hash)]
+struct Person {
+    id: uint,
+    name: ~str,
+    phone: uint,
+}
+
+fn main() {
+    let person1 = Person { id: 5, name: ~"Janet", phone: 555_666_7777 };
+    let person2 = Person { id: 5, name: ~"Bob", phone: 555_666_7777 };
+    assert!(hash::hash(&person1) == hash::hash(&person1));
+    assert!(hash::hash(&person1) != hash::hash(&person2));
+}
diff --git a/src/test/run-pass/deriving-meta-multiple.rs b/src/test/run-pass/deriving-meta-multiple.rs
index c65cae6d3b9..49bf101954b 100644
--- a/src/test/run-pass/deriving-meta-multiple.rs
+++ b/src/test/run-pass/deriving-meta-multiple.rs
@@ -10,6 +10,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use std::hash_old::Hash;
+
 #[deriving(Eq)]
 #[deriving(Clone)]
 #[deriving(IterBytes)]
diff --git a/src/test/run-pass/deriving-meta.rs b/src/test/run-pass/deriving-meta.rs
index cbe54790404..93193fc9d65 100644
--- a/src/test/run-pass/deriving-meta.rs
+++ b/src/test/run-pass/deriving-meta.rs
@@ -10,6 +10,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use std::hash_old::Hash;
+
 #[deriving(Eq, Clone, IterBytes)]
 struct Foo {
     bar: uint,
diff --git a/src/test/run-pass/typeid-intrinsic.rs b/src/test/run-pass/typeid-intrinsic.rs
index 71e19b51c72..2d5c1d100be 100644
--- a/src/test/run-pass/typeid-intrinsic.rs
+++ b/src/test/run-pass/typeid-intrinsic.rs
@@ -15,6 +15,7 @@
 extern crate other1 = "typeid-intrinsic";
 extern crate other2 = "typeid-intrinsic2";
 
+use std::hash_old::Hash;
 use std::unstable::intrinsics;
 use std::unstable::intrinsics::TypeId;