2 files changed, 8 insertions, 2 deletions
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 4d79ff3257a..4d3913da365 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -148,6 +148,8 @@ pub trait AstBuilder {
     fn expr_some(&self, sp: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr>;
     fn expr_none(&self, sp: Span) -> Gc<ast::Expr>;
 
+    fn expr_tuple(&self, sp: Span, exprs: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr>;
+
     fn expr_fail(&self, span: Span, msg: InternedString) -> Gc<ast::Expr>;
     fn expr_unreachable(&self, span: Span) -> Gc<ast::Expr>;
 
@@ -674,6 +676,10 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         self.expr_path(none)
     }
 
+    fn expr_tuple(&self, sp: Span, exprs: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr> {
+        self.expr(sp, ast::ExprTup(exprs))
+    }
+
     fn expr_fail(&self, span: Span, msg: InternedString) -> Gc<ast::Expr> {
         let loc = self.codemap().lookup_char_pos(span.lo);
         self.expr_call_global(
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index b7d72ae4deb..b5f7005c2a3 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -58,7 +58,7 @@ pub fn expand_expr(e: Gc<ast::Expr>, fld: &mut MacroExpander) -> Gc<ast::Expr> {
                         None => {
                             fld.cx.span_err(
                                 pth.span,
-                                format!("macro undefined: '{}'",
+                                format!("macro undefined: '{}!'",
                                         extnamestr.get()).as_slice());
 
                             // let compilation continue
@@ -567,7 +567,7 @@ fn expand_stmt(s: &Stmt, fld: &mut MacroExpander) -> SmallVector<Gc<Stmt>> {
     let marked_after = match fld.extsbox.find(&extname.name) {
         None => {
             fld.cx.span_err(pth.span,
-                            format!("macro undefined: '{}'",
+                            format!("macro undefined: '{}!'",
                                     extnamestr).as_slice());
             return SmallVector::zero();
         }