Allow syntax extensions to return multiple items, closes #16723.

This patch replaces `MacItem` with `MacItems`.

2 files changed, 15 insertions, 20 deletions

diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index 132b59c89b2..d3c39284f55 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -13,7 +13,7 @@ use std::collections::HashMap;
 use ast;
 use ast::{Ident, Name, TokenTree};
 use codemap::Span;
-use ext::base::{ExtCtxt, MacExpr, MacItem, MacResult};
+use ext::base::{ExtCtxt, MacExpr, MacResult, MacItems};
 use ext::build::AstBuilder;
 use parse::token;
 use ptr::P;
@@ -102,7 +102,7 @@ pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt,
     let sym = Ident::new(token::gensym((
         "__register_diagnostic_".to_string() + token::get_ident(*code).get()
     ).as_slice()));
-    MacItem::new(quote_item!(ecx, mod $sym {}).unwrap())
+    MacItems::new(vec![quote_item!(ecx, mod $sym {}).unwrap()].into_iter())
 }
 
 pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
@@ -133,7 +133,7 @@ pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
             (descriptions.len(), ecx.expr_vec(span, descriptions))
         })
     });
-    MacItem::new(quote_item!(ecx,
+    MacItems::new(vec![quote_item!(ecx,
         pub static $name: [(&'static str, &'static str), ..$count] = $expr;
-    ).unwrap())
+    ).unwrap()].into_iter())
 }
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 773daa4a4c5..fbbbea541a6 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -203,25 +203,20 @@ impl MacResult for MacPat {
         Some(self.p)
     }
 }
-/// A convenience type for macros that return a single item.
-pub struct MacItem {
-    i: P<ast::Item>
+/// A type for macros that return multiple items.
+pub struct MacItems {
+    items: SmallVector<P<ast::Item>>
 }
-impl MacItem {
-    pub fn new(i: P<ast::Item>) -> Box<MacResult+'static> {
-        box MacItem { i: i } as Box<MacResult+'static>
+
+impl MacItems {
+    pub fn new<I: Iterator<P<ast::Item>>>(mut it: I) -> Box<MacResult+'static> {
+        box MacItems { items: it.collect() } as Box<MacResult+'static>
     }
 }
-impl MacResult for MacItem {
-    fn make_items(self: Box<MacItem>) -> Option<SmallVector<P<ast::Item>>> {
-        Some(SmallVector::one(self.i))
-    }
-    fn make_stmt(self: Box<MacItem>) -> Option<P<ast::Stmt>> {
-        Some(P(codemap::respan(
-            self.i.span,
-            ast::StmtDecl(
-                P(codemap::respan(self.i.span, ast::DeclItem(self.i))),
-                ast::DUMMY_NODE_ID))))
+
+impl MacResult for MacItems {
+    fn make_items(self: Box<MacItems>) -> Option<SmallVector<P<ast::Item>>> {
+        Some(self.items)
     }
 }