---

yaml
---
r: 126177
b: refs/heads/auto
c: 8c4dbf3
h: refs/heads/master
i:
  126175: 0eb757a
v: v3

Author: Cameron Zwarich

[refs]

@@ -13,7 +13,7 @@ refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0
 refs/tags/release-0.3.1: 495bae036dfe5ec6ceafd3312b4dca48741e845b
 refs/tags/release-0.4: e828ea2080499553b97dfe33b3f4d472b4562ad7
 refs/tags/release-0.5: 7e3bcfbf21278251ee936ad53e92e9b719702d73
-refs/heads/auto: 8da03d9771bc827eae713d16bca7bec4c5fe6a10
+refs/heads/auto: 8c4dbf3d4750feb47aec09b3f2df848e8f7b5469
 refs/heads/servo: af82457af293e2a842ba6b7759b70288da276167
 refs/tags/release-0.6: b4ebcfa1812664df5e142f0134a5faea3918544c
 refs/tags/0.1: b19db808c2793fe2976759b85a355c3ad8c8b336

branches/auto/src/librustc/middle/borrowck/check_loans.rs

@@ -28,6 +28,57 @@ use util::ppaux::Repr;
 
 use std::rc::Rc;
 
+// FIXME (#16118): These functions are intended to allow the borrow checker to
+// be less precise in its handling of Box while still allowing moves out of a
+// Box. They should be removed when OwnedPtr is removed from LoanPath.
+
+fn owned_ptr_base_path<'a>(loan_path: &'a LoanPath) -> &'a LoanPath {
+    //! Returns the base of the leftmost dereference of an OwnedPtr in
+    //! `loan_path`. If there is no dereference of an OwnedPtr in `loan_path`,
+    //! then it just returns `loan_path` itself.
+
+    return match owned_ptr_base_path_helper(loan_path) {
+        Some(new_loan_path) => new_loan_path,
+        None => loan_path.clone()
+    };
+
+    fn owned_ptr_base_path_helper<'a>(loan_path: &'a LoanPath) -> Option<&'a LoanPath> {
+        match *loan_path {
+            LpVar(_) | LpUpvar(_) => None,
+            LpExtend(ref lp_base, _, LpDeref(mc::OwnedPtr)) => {
+                match owned_ptr_base_path_helper(&**lp_base) {
+                    v @ Some(_) => v,
+                    None => Some(&**lp_base)
+                }
+            }
+            LpExtend(ref lp_base, _, _) => owned_ptr_base_path_helper(&**lp_base)
+        }
+    }
+}
+
+fn owned_ptr_base_path_rc(loan_path: &Rc<LoanPath>) -> Rc<LoanPath> {
+    //! The equivalent of `owned_ptr_base_path` for an &Rc<LoanPath> rather than
+    //! a &LoanPath.
+
+    return match owned_ptr_base_path_helper(loan_path) {
+        Some(new_loan_path) => new_loan_path,
+        None => loan_path.clone()
+    };
+
+    fn owned_ptr_base_path_helper(loan_path: &Rc<LoanPath>) -> Option<Rc<LoanPath>> {
+        match **loan_path {
+            LpVar(_) | LpUpvar(_) => None,
+            LpExtend(ref lp_base, _, LpDeref(mc::OwnedPtr)) => {
+                match owned_ptr_base_path_helper(lp_base) {
+                    v @ Some(_) => v,
+                    None => Some(lp_base.clone())
+                }
+            }
+            LpExtend(ref lp_base, _, _) => owned_ptr_base_path_helper(lp_base)
+        }
+    }
+}
+
 struct CheckLoanCtxt<'a> {
     bccx: &'a BorrowckCtxt<'a>,
     dfcx_loans: &'a LoanDataFlow<'a>,