Derive HashStable_Generic for ExpnData.

Author: cjgillot

src/librustc/ich/impls_syntax.rs

@@ -197,17 +197,6 @@ impl_stable_hash_for!(enum ::syntax::ast::MetaItemKind {
     NameValue(lit)
 });
 
-impl_stable_hash_for!(struct ::syntax_pos::hygiene::ExpnData {
-    kind,
-    parent -> _,
-    call_site,
-    def_site,
-    allow_internal_unstable,
-    allow_internal_unsafe,
-    local_inner_macros,
-    edition
-});
-
 impl<'a> HashStable<StableHashingContext<'a>> for SourceFile {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         let SourceFile {

src/libsyntax_pos/hygiene.rs

@@ -616,12 +616,13 @@ impl Span {
 
 /// A subset of properties from both macro definition and macro call available through global data.
 /// Avoid using this if you have access to the original definition or call structures.
-#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable_Generic)]
 pub struct ExpnData {
     // --- The part unique to each expansion.
     /// The kind of this expansion - macro or compiler desugaring.
     pub kind: ExpnKind,
     /// The expansion that produced this expansion.
+    #[stable_hasher(ignore)]
     pub parent: ExpnId,
     /// The location of the actual macro invocation or syntax sugar , e.g.
     /// `let x = foo!();` or `if let Some(y) = x {}`