Use proc-macro to derive HashStable everywhere

src/librustc/ich/hcx.rs

@@ -14,7 +14,6 @@ use std::cell::RefCell;
 use syntax::ast;
 use syntax::source_map::SourceMap;
 use syntax::symbol::Symbol;
-use syntax::tokenstream::DelimSpan;
 use syntax_pos::{Span, DUMMY_SP};
 use syntax_pos::hygiene::{self, SyntaxContext};
 
@@ -364,13 +363,6 @@ impl<'a> syntax_pos::StableHashingContextLike for StableHashingContext<'a> {
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>> for DelimSpan {
-    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        self.open.hash_stable(hcx, hasher);
-        self.close.hash_stable(hcx, hasher);
-    }
-}
-
 pub fn hash_stable_trait_impls<'a>(
     hcx: &mut StableHashingContext<'a>,
     hasher: &mut StableHasher,

src/librustc/ich/impls_syntax.rs

@@ -20,12 +20,6 @@ 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!(struct ::syntax::ast::Lit {
-    kind,
-    token,
-    span
-});
-
 impl_stable_hash_for_spanned!(::syntax::ast::LitKind);
 
 impl_stable_hash_for!(struct ::syntax::ast::Lifetime { id, ident });
@@ -53,15 +47,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for [ast::Attribute] {
     }
 }
 
-impl<'a> HashStable<StableHashingContext<'a>> for ast::Path {
-    fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
-        self.segments.len().hash_stable(hcx, hasher);
-        for segment in &self.segments {
-            segment.ident.name.hash_stable(hcx, hasher);
-        }
-    }
-}
-
 impl_stable_hash_for!(struct ::syntax::ast::AttrItem {
     path,
     tokens,

src/libsyntax/ast.rs

@@ -33,6 +33,7 @@ use syntax_pos::symbol::{kw, sym, Symbol};
 use syntax_pos::{Span, DUMMY_SP, ExpnId};
 
 use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::thin_vec::ThinVec;
 use rustc_index::vec::Idx;
@@ -112,6 +113,15 @@ impl PartialEq<Symbol> for Path {
     }
 }
 
+impl<CTX> HashStable<CTX> for Path {
+    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
+        self.segments.len().hash_stable(hcx, hasher);
+        for segment in &self.segments {
+            segment.ident.name.hash_stable(hcx, hasher);
+        }
+    }
+}
+
 impl Path {
     // Convert a span and an identifier to the corresponding
     // one-segment path.
@@ -1411,7 +1421,7 @@ pub enum StrStyle {
 }
 
 /// An AST literal.
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
+#[derive(Clone, RustcEncodable, RustcDecodable, Debug, HashStable_Generic)]
 pub struct Lit {
     /// The original literal token as written in source code.
     pub token: token::Lit,

src/libsyntax/lib.rs

@@ -114,4 +114,4 @@ 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 {}
+pub trait StableHashingContextLike: syntax_pos::StableHashingContextLike {}

src/libsyntax/tokenstream.rs

@@ -444,7 +444,7 @@ impl Cursor {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)]
+#[derive(Debug, Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, HashStable_Generic)]
 pub struct DelimSpan {
     pub open: Span,
     pub close: Span,