---

yaml
---
r: 205117
b: refs/heads/tmp
c: f97cff9
h: refs/heads/master
i:
  205115: 7a37c51
v: v3

Author: aochagavia

[refs]

@@ -32,7 +32,7 @@ refs/heads/building: 126db549b038c84269a1e4fe46f051b2c15d6970
 refs/heads/beta: f0213d8ffb128a16f94af7ee985dc61484596163
 refs/heads/windistfix: 7608dbad651f02e837ed05eef3d74a6662a6e928
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
-refs/heads/tmp: 77d59217a38e2982fdcf6bff800f1c9acc0d9aaf
+refs/heads/tmp: f97cff9abd4ea7a7a8ac24bb9afb09eb271bcda9
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: f0ac7e04e647381e2bb87de1f3d0b108acb24d06
 refs/heads/gate: 97c84447b65164731087ea82685580cc81424412

branches/tmp/src/libsyntax/ext/base.rs

@@ -418,11 +418,15 @@ impl MacResult for DummyResult {
 
 /// An enum representing the different kinds of syntax extensions.
 pub enum SyntaxExtension {
+    /// A syntax extension that is attached to an item and creates new items
+    /// based upon it.
+    Decorator(Box<ItemDecorator + 'static>),
+
     /// A syntax extension that is attached to an item and creates new items
     /// based upon it.
     ///
     /// `#[derive(...)]` is an `ItemDecorator`.
-    Decorator(Box<ItemDecorator + 'static>),
+    MultiDecorator(Box<MultiItemDecorator + 'static>),
 
     /// A syntax extension that is attached to an item and modifies it
     /// in-place.

branches/tmp/src/libsyntax/ext/expand.rs

@@ -1096,6 +1096,28 @@ fn expand_annotatable(a: Annotatable,
 
                     fld.cx.bt_pop();
                 }
+                MultiDecorator(ref dec) => {
+                    attr::mark_used(attr);
+
+                    fld.cx.bt_push(ExpnInfo {
+                        call_site: attr.span,
+                        callee: NameAndSpan {
+                            name: mname.get().to_string(),
+                            format: MacroAttribute,
+                            span: None
+                        }
+                    });
+
+                    // we'd ideally decorator_items.push_all(expand_item(item, fld)),
+                    // but that double-mut-borrows fld
+                    let mut items: SmallVector<P<ast::Item>> = SmallVector::zero();
+                    dec.expand(fld.cx, attr.span, &*attr.node.value, a,
+                               box |&mut: item| items.push(item));
+                    decorator_items.extend(items.into_iter()
+                        .flat_map(|item| expand_item(item, fld).into_iter()));
+
+                    fld.cx.bt_pop();
+                }
                 _ => new_attrs.push((*attr).clone()),
             },
             _ => new_attrs.push((*attr).clone()),