Use proc-macro to derive HashStable everywhere

src/librustc/ich/impls_syntax.rs

@@ -9,15 +9,13 @@ use std::mem;
 use syntax::ast;
 use syntax::feature_gate;
 use syntax::token;
-use syntax::tokenstream;
 use syntax_pos::SourceFile;
 
 use crate::hir::def_id::{DefId, CrateNum, CRATE_DEF_INDEX};
 
 use smallvec::SmallVec;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 
-impl<'ctx> syntax::StableHashingContextLike for StableHashingContext<'ctx> {}
 impl<'ctx> rustc_target::StableHashingContextLike for StableHashingContext<'ctx> {}
 
 impl_stable_hash_for_spanned!(::syntax::ast::LitKind);
@@ -47,11 +45,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for [ast::Attribute] {
     }
 }
 
-impl_stable_hash_for!(struct ::syntax::ast::AttrItem {
-    path,
-    tokens,
-});
-
 impl<'a> HashStable<StableHashingContext<'a>> for ast::Attribute {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         // Make sure that these have been filtered out.
@@ -69,38 +62,10 @@ impl<'a> HashStable<StableHashingContext<'a>> for ast::Attribute {
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>>
-for tokenstream::TokenTree {
-    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        mem::discriminant(self).hash_stable(hcx, hasher);
-        match *self {
-            tokenstream::TokenTree::Token(ref token) => {
-                token.hash_stable(hcx, hasher);
-            }
-            tokenstream::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<'a> HashStable<StableHashingContext<'a>>
-for tokenstream::TokenStream {
-    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        for sub_tt in self.trees() {
-            sub_tt.hash_stable(hcx, hasher);
-        }
-    }
-}
-
-impl<'a> HashStable<StableHashingContext<'a>> for token::TokenKind {
-    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        mem::discriminant(self).hash_stable(hcx, hasher);
-        match *self {
+impl<'ctx> syntax::StableHashingContextLike for StableHashingContext<'ctx> {
+    fn hash_stable_tokenkind(&mut self, tokenkind: &token::TokenKind, hasher: &mut StableHasher) {
+        mem::discriminant(tokenkind).hash_stable(self, hasher);
+        match *tokenkind {
             token::Eq |
             token::Lt |
             token::Le |
@@ -141,30 +106,25 @@ impl<'a> HashStable<StableHashingContext<'a>> for token::TokenKind {
             token::CloseDelim(delim_token) => {
                 std_hash::Hash::hash(&delim_token, hasher);
             }
-            token::Literal(lit) => lit.hash_stable(hcx, hasher),
+            token::Literal(lit) => lit.hash_stable(self, hasher),
 
             token::Ident(name, is_raw) => {
-                name.hash_stable(hcx, hasher);
-                is_raw.hash_stable(hcx, hasher);
+                name.hash_stable(self, hasher);
+                is_raw.hash_stable(self, hasher);
             }
-            token::Lifetime(name) => name.hash_stable(hcx, hasher),
+            token::Lifetime(name) => name.hash_stable(self, hasher),
 
             token::Interpolated(_) => {
                 bug!("interpolated tokens should not be present in the HIR")
             }
 
             token::DocComment(val) |
             token::Shebang(val) |
-            token::Unknown(val) => val.hash_stable(hcx, hasher),
+            token::Unknown(val) => val.hash_stable(self, hasher),
         }
     }
 }
 
-impl_stable_hash_for!(struct token::Token {
-    kind,
-    span
-});
-
 impl_stable_hash_for!(enum ::syntax::ast::NestedMetaItem {
     MetaItem(meta_item),
     Literal(lit)

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,

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);
+}

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,

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