---

yaml
---
r: 152903
b: refs/heads/try2
c: 04e64c0
h: refs/heads/master
i:
  152901: 08a3a95
  152899: 1890590
  152895: 38db87d
v: v3

Author: luqmana

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: abdf71cf73fd8b0b5bca78da830fe6f2a49ff8c2
+refs/heads/try2: 04e64c0c91f1d0de04940eab76ddcfe126d635b1
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/librustc/middle/trans/expr.rs

@@ -277,15 +277,19 @@ fn apply_adjustments<'a>(bcx: &'a Block<'a>,
         auto_ref(bcx, datum, expr)
     }
 
-    fn auto_borrow_obj<'a>(bcx: &'a Block<'a>,
+    fn auto_borrow_obj<'a>(mut bcx: &'a Block<'a>,
                            expr: &ast::Expr,
                            source_datum: Datum<Expr>)
                            -> DatumBlock<'a, Expr> {
         let tcx = bcx.tcx();
         let target_obj_ty = expr_ty_adjusted(bcx, expr);
         debug!("auto_borrow_obj(target={})", target_obj_ty.repr(tcx));
 
-        let mut datum = source_datum.to_expr_datum();
+        // Arrange cleanup, if not already done. This is needed in
+        // case we are auto-borrowing a Box<Trait> to &Trait
+        let datum = unpack_datum!(
+            bcx, source_datum.to_lvalue_datum(bcx, "autoborrowobj", expr.id));
+        let mut datum = datum.to_expr_datum();
         datum.ty = target_obj_ty;
         DatumBlock::new(bcx, datum)
     }

branches/try2/src/test/run-pass/cleanup-auto-borrow-obj.rs

@@ -0,0 +1,38 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+
+// This would previously leak the Box<Trait> because we wouldn't
+// schedule cleanups when auto borrowing trait objects.
+// This program should be valgrind clean.
+
+
+static mut DROP_RAN: bool = false;
+
+struct Foo;
+impl Drop for Foo {
+    fn drop(&mut self) {
+        unsafe { DROP_RAN = true; }
+    }
+}
+
+
+trait Trait {}
+impl Trait for Foo {}
+
+pub fn main() {
+    {
+        let _x: &Trait = box Foo as Box<Trait>;
+    }
+    unsafe {
+        assert!(DROP_RAN);
+    }
+}
+