Invert implementations for TokenKind.

Also export a bunch of Token-related impls.

4 files changed, 46 insertions, 3 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 01abd09aa91..3cc6a043e3b 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -2276,7 +2276,7 @@ impl rustc_serialize::Decodable for AttrId {
     }
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable_Generic)]
 pub struct AttrItem {
     pub path: Path,
     pub tokens: TokenStream,
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 7865323f842..939e1877b4a 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -20,6 +20,7 @@
 #![recursion_limit="256"]
 
 pub use errors;
+use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::Lock;
 use rustc_index::bit_set::GrowableBitSet;
 pub use rustc_data_structures::thin_vec::ThinVec;
@@ -114,4 +115,6 @@ pub mod early_buffered_lints;
 /// Requirements for a `StableHashingContext` to be used in this crate.
 /// This is a hack to allow using the `HashStable_Generic` derive macro
 /// instead of implementing everything in librustc.
-pub trait StableHashingContextLike: syntax_pos::StableHashingContextLike {}
+pub trait StableHashingContextLike: syntax_pos::StableHashingContextLike {
+    fn hash_stable_tokenkind(&mut self, tokenkind: &token::TokenKind, hasher: &mut StableHasher);
+}
diff --git a/src/libsyntax/token.rs b/src/libsyntax/token.rs
index fd1623384a4..305db739399 100644
--- a/src/libsyntax/token.rs
+++ b/src/libsyntax/token.rs
@@ -14,6 +14,7 @@ use syntax_pos::{self, Span, DUMMY_SP};
 
 use std::fmt;
 use std::mem;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_macros::HashStable_Generic;
 
@@ -262,7 +263,15 @@ pub enum TokenKind {
 #[cfg(target_arch = "x86_64")]
 rustc_data_structures::static_assert_size!(TokenKind, 16);
 
-#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
+impl<CTX> HashStable<CTX> for TokenKind
+    where CTX: crate::StableHashingContextLike
+{
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        hcx.hash_stable_tokenkind(self, hasher)
+    }
+}
+
+#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, HashStable_Generic)]
 pub struct Token {
     pub kind: TokenKind,
     pub span: Span,
diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
index 40f00aaa5d8..6de9a0fb070 100644
--- a/src/libsyntax/tokenstream.rs
+++ b/src/libsyntax/tokenstream.rs
@@ -16,6 +16,7 @@
 use crate::token::{self, DelimToken, Token, TokenKind};
 
 use syntax_pos::{Span, DUMMY_SP};
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use smallvec::{SmallVec, smallvec};
 
@@ -51,6 +52,26 @@ where
     TokenStream: Send + Sync,
 {}
 
+impl<CTX> HashStable<CTX> for TokenTree
+    where CTX: crate::StableHashingContextLike
+{
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+        match *self {
+            TokenTree::Token(ref token) => {
+                token.hash_stable(hcx, hasher);
+            }
+            TokenTree::Delimited(span, delim, ref tts) => {
+                span.hash_stable(hcx, hasher);
+                std::hash::Hash::hash(&delim, hasher);
+                for sub_tt in tts.trees() {
+                    sub_tt.hash_stable(hcx, hasher);
+                }
+            }
+        }
+    }
+}
+
 impl TokenTree {
     /// Checks if this TokenTree is equal to the other, regardless of span information.
     pub fn eq_unspanned(&self, other: &TokenTree) -> bool {
@@ -115,6 +136,16 @@ impl TokenTree {
     }
 }
 
+impl<CTX> HashStable<CTX> for TokenStream
+    where CTX: crate::StableHashingContextLike
+{
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        for sub_tt in self.trees() {
+            sub_tt.hash_stable(hcx, hasher);
+        }
+    }
+}
+
 /// A `TokenStream` is an abstract sequence of tokens, organized into `TokenTree`s.
 ///
 /// The goal is for procedural macros to work with `TokenStream`s and `TokenTree`s