rustc: Allow attributes on enum variants. Closes #1663

Author: brson

src/comp/syntax/ast.rs

@@ -418,8 +418,8 @@ type native_mod =
 
 type variant_arg = {ty: @ty, id: node_id};
 
-type variant_ = {name: ident, args: [variant_arg], id: node_id,
-                 disr_expr: option::t<@expr>};
+type variant_ = {name: ident, attrs: [attribute], args: [variant_arg],
+                 id: node_id, disr_expr: option::t<@expr>};
 
 type variant = spanned<variant_>;
 

src/comp/syntax/fold.rs

@@ -441,11 +441,18 @@ fn noop_fold_variant(v: variant_, fld: ast_fold) -> variant_ {
     }
     let fold_variant_arg = bind fold_variant_arg_(_, fld);
     let args = vec::map(v.args, fold_variant_arg);
+
+    let fold_meta_item = bind fold_meta_item_(_, fld);
+    let fold_attribute = bind fold_attribute_(_, fold_meta_item);
+    let attrs = vec::map(v.attrs, fold_attribute);
+
     let de = alt v.disr_expr {
       some(e) {some(fld.fold_expr(e))}
       none {none}
     };
-    ret {name: v.name, args: args, id: v.id,
+    ret {name: v.name,
+         attrs: attrs,
+         args: args, id: v.id,
          disr_expr: de};
 }
 

src/comp/syntax/parse/parser.rs

@@ -2042,16 +2042,19 @@ fn parse_item_enum(p: parser, attrs: [ast::attribute]) -> @ast::item {
         let variant =
             spanned(ty.span.lo, ty.span.hi,
                     {name: id,
+                     attrs: [],
                      args: [{ty: ty, id: p.get_id()}],
                      id: p.get_id(),
                      disr_expr: none});
         ret mk_item(p, lo, ty.span.hi, id,
                     ast::item_enum([variant], ty_params), attrs);
     }
     expect(p, token::LBRACE);
+
     let all_nullary = true, have_disr = false;
 
     while p.token != token::RBRACE {
+        let variant_attrs = parse_outer_attributes(p);
         let vlo = p.span.lo;
         let ident = parse_value_ident(p);
         let args = [], disr_expr = none;
@@ -2068,7 +2071,8 @@ fn parse_item_enum(p: parser, attrs: [ast::attribute]) -> @ast::item {
             disr_expr = some(parse_expr(p));
         }
 
-        let vr = {name: ident, args: args, id: p.get_id(),
+        let vr = {name: ident, attrs: variant_attrs,
+                  args: args, id: p.get_id(),
                   disr_expr: disr_expr};
         variants += [spanned(vlo, p.last_span.hi, vr)];
 

src/comp/syntax/print/pprust.rs

@@ -434,6 +434,7 @@ fn print_item(s: ps, &&item: @ast::item) {
             for v: ast::variant in variants {
                 space_if_not_bol(s);
                 maybe_print_comment(s, v.span.lo);
+                print_outer_attributes(s, v.node.attrs);
                 ibox(s, indent_unit);
                 word(s.s, v.node.name);
                 if vec::len(v.node.args) > 0u {

src/test/run-pass/variant-attributes.rs

@@ -0,0 +1,29 @@
+// pp-exact - Make sure we actually print the attributes
+
+enum crew_of_enterprise_d {
+
+    #[captain]
+    jean_luc_picard,
+
+    #[commander]
+    william_t_riker,
+
+    #[chief_medical_officer]
+    beverly_crusher,
+
+    #[ships_councellor]
+    deanna_troi,
+
+    #[lieutenant_commander]
+    data,
+
+    #[chief_of_security]
+    worf,
+
+    #[chief_engineer]
+    geordi_la_forge,
+}
+
+fn boldly_go(_crew_member: crew_of_enterprise_d, _where: str) { }
+
+fn main() { boldly_go(worf, "where no one has gone before"); }