---

yaml
---
r: 148351
b: refs/heads/try2
c: 56f4d18
h: refs/heads/master
i:
  148349: 8949534
  148347: db96c23
  148343: 0f2ea97
  148335: 32605e8
  148319: c42340e
  148287: d4974aa
  148223: 57cdbda
v: v3

Author: nikomatsakis

[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: 0c916c58e8c978554415933773f0a105dee754d3
+refs/heads/try2: 56f4d1831a65b9739d38c2754f65b641b4e0d6b8
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/librustc/middle/borrowck/gather_loans/lifetime.rs

@@ -67,6 +67,9 @@ impl<'a> GuaranteeLifetimeContext<'a> {
 
     fn check(&self, cmt: mc::cmt, discr_scope: Option<ast::NodeId>) -> R {
         //! Main routine. Walks down `cmt` until we find the "guarantor".
+        debug!("guarantee_lifetime.check(cmt={}, loan_region={})",
+               cmt.repr(self.bccx.tcx),
+               self.loan_region.repr(self.bccx.tcx));
 
         match cmt.cat {
             mc::cat_rvalue(..) |

branches/try2/src/librustc/middle/typeck/check/regionck.rs

@@ -213,6 +213,7 @@ fn visit_arm(rcx: &mut Rcx, arm: &ast::Arm) {
 fn visit_local(rcx: &mut Rcx, l: &ast::Local) {
     // see above
     constrain_bindings_in_pat(l.pat, rcx);
+    guarantor::for_local(rcx, l);
     visit::walk_local(rcx, l, ());
 }
 
@@ -828,6 +829,30 @@ pub mod guarantor {
         }
     }
 
+    pub fn for_local(rcx: &mut Rcx, local: &ast::Local) {
+        /*!
+         * Link the lifetimes of any ref bindings in a let
+         * pattern to the lifetimes in the initializer.
+         *
+         * For example, given something like this:
+         *
+         *    let &Foo(ref x) = ...;
+         *
+         * this would ensure that the lifetime 'a of the
+         * region pointer being matched must be >= the lifetime
+         * of the ref binding.
+         */
+
+        debug!("regionck::for_match()");
+        let init_expr = match local.init {
+            None => { return; }
+            Some(e) => e
+        };
+        let init_guarantor = guarantor(rcx, init_expr);
+        debug!("init_guarantor={}", init_guarantor.repr(rcx.tcx()));
+        link_ref_bindings_in_pat(rcx, local.pat, init_guarantor);
+    }
+
     pub fn for_autoref(rcx: &mut Rcx,
                        expr: &ast::Expr,
                        autoderefs: uint,

branches/try2/src/test/compile-fail/borrowck-borrow-from-temporary.rs

@@ -0,0 +1,22 @@
+// Copyright 2012 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.
+
+// Test lifetimes are linked properly when we take reference
+// to interior.
+
+struct Foo(int);
+
+fn foo() -> &int {
+    let &Foo(ref x) = &Foo(3); //~ ERROR borrowed value does not live long enough
+    x
+}
+
+pub fn main() {
+}

branches/try2/src/test/debug-info/destructured-local.rs

@@ -196,13 +196,13 @@ fn main() {
     let Unit(ii) = Unit(51);
 
     // univariant enum with ref      binding
-    let Unit(ref jj) = Unit(52);
+    let &Unit(ref jj) = &Unit(52);
 
     // tuple struct
-    let TupleStruct(kk, ll) = TupleStruct(53.0, 54);
+    let &TupleStruct(kk, ll) = &TupleStruct(53.0, 54);
 
     // tuple struct with ref binding
-    let TupleStruct(mm, ref nn) = TupleStruct(55.0, 56);
+    let &TupleStruct(mm, ref nn) = &TupleStruct(55.0, 56);
 
     zzz();
 }

branches/try2/src/test/run-pass/regions-dependent-let-ref.rs

@@ -0,0 +1,19 @@
+// Copyright 2012 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.
+
+// Test lifetimes are linked properly when we take reference
+// to interior.
+
+struct Foo(int);
+pub fn main() {
+    // Here the lifetime of the `&` should be at least the
+    // block, since a ref binding is created to the interior.
+    let &Foo(ref _x) = &Foo(3);
+}