correct incorrect handling of overloaded operators, exposing various other bits of rot

9 files changed, 117 insertions, 129 deletions

diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 86b36834bbd..85e46a0feff 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -296,34 +296,34 @@ impl<T> Ord for *const T {
 
 // Equality for region pointers
 #[cfg(notest)]
-impl<'self,T:Eq> Eq for &'self const T {
+impl<'self,T:Eq> Eq for &'self T {
     #[inline(always)]
-    fn eq(&self, other: & &'self const T) -> bool {
+    fn eq(&self, other: & &'self T) -> bool {
         return *(*self) == *(*other);
     }
     #[inline(always)]
-    fn ne(&self, other: & &'self const T) -> bool {
+    fn ne(&self, other: & &'self T) -> bool {
         return *(*self) != *(*other);
     }
 }
 
 // Comparison for region pointers
 #[cfg(notest)]
-impl<'self,T:Ord> Ord for &'self const T {
+impl<'self,T:Ord> Ord for &'self T {
     #[inline(always)]
-    fn lt(&self, other: & &'self const T) -> bool {
+    fn lt(&self, other: & &'self T) -> bool {
         *(*self) < *(*other)
     }
     #[inline(always)]
-    fn le(&self, other: & &'self const T) -> bool {
+    fn le(&self, other: & &'self T) -> bool {
         *(*self) <= *(*other)
     }
     #[inline(always)]
-    fn ge(&self, other: & &'self const T) -> bool {
+    fn ge(&self, other: & &'self T) -> bool {
         *(*self) >= *(*other)
     }
     #[inline(always)]
-    fn gt(&self, other: & &'self const T) -> bool {
+    fn gt(&self, other: & &'self T) -> bool {
         *(*self) > *(*other)
     }
 }
diff --git a/src/librustc/middle/borrowck/gather_loans/mod.rs b/src/librustc/middle/borrowck/gather_loans/mod.rs
index 8a986a22d4c..ecdf260bfff 100644
--- a/src/librustc/middle/borrowck/gather_loans/mod.rs
+++ b/src/librustc/middle/borrowck/gather_loans/mod.rs
@@ -68,8 +68,7 @@ struct GatherLoanCtxt {
     id_range: id_range,
     all_loans: @mut ~[Loan],
     item_ub: ast::node_id,
-    repeating_ids: ~[ast::node_id],
-    ignore_adjustments: HashSet<ast::node_id>
+    repeating_ids: ~[ast::node_id]
 }
 
 pub fn gather_loans(bccx: @BorrowckCtxt,
@@ -79,8 +78,7 @@ pub fn gather_loans(bccx: @BorrowckCtxt,
         id_range: id_range::max(),
         all_loans: @mut ~[],
         item_ub: body.node.id,
-        repeating_ids: ~[body.node.id],
-        ignore_adjustments: HashSet::new()
+        repeating_ids: ~[body.node.id]
     };
     let v = visit::mk_vt(@visit::Visitor {visit_expr: gather_loans_in_expr,
                                           visit_block: gather_loans_in_block,
@@ -147,13 +145,8 @@ fn gather_loans_in_expr(ex: @ast::expr,
     self.id_range.add(ex.callee_id);
 
     // If this expression is borrowed, have to ensure it remains valid:
-    {
-        let this = &mut *self; // FIXME(#5074)
-        if !this.ignore_adjustments.contains(&ex.id) {
-            for tcx.adjustments.find(&ex.id).each |&adjustments| {
-                this.guarantee_adjustments(ex, *adjustments);
-            }
-        }
+    for tcx.adjustments.find(&ex.id).each |&adjustments| {
+        self.guarantee_adjustments(ex, *adjustments);
     }
 
     // Special checks for various kinds of expressions:
@@ -178,46 +171,20 @@ fn gather_loans_in_expr(ex: @ast::expr,
         visit::visit_expr(ex, self, vt);
       }
 
-      ast::expr_index(rcvr, _) |
-      ast::expr_binary(_, rcvr, _) |
-      ast::expr_unary(_, rcvr) |
-      ast::expr_assign_op(_, rcvr, _)
+      ast::expr_index(_, arg) |
+      ast::expr_binary(_, _, arg)
       if self.bccx.method_map.contains_key(&ex.id) => {
-        // Receivers in method calls are always passed by ref.
-        //
-        // Here, in an overloaded operator, the call is this expression,
-        // and hence the scope of the borrow is this call.
-        //
-        // FIX? / NOT REALLY---technically we should check the other
-        // argument and consider the argument mode.  But how annoying.
-        // And this problem when goes away when argument modes are
-        // phased out.  So I elect to leave this undone.
-        let scope_r = ty::re_scope(ex.id);
-        let rcvr_cmt = self.bccx.cat_expr(rcvr);
-        self.guarantee_valid(rcvr.id, rcvr.span, rcvr_cmt, m_imm, scope_r);
-
-        // FIXME (#3387): Total hack: Ignore adjustments for the left-hand
-        // side. Their regions will be inferred to be too large.
-        self.ignore_adjustments.insert(rcvr.id);
-
-        visit::visit_expr(ex, self, vt);
+          // Arguments in method calls are always passed by ref.
+          //
+          // Currently these do not use adjustments, so we have to
+          // hardcode this check here (note that the receiver DOES use
+          // adjustments).
+          let scope_r = ty::re_scope(ex.id);
+          let arg_cmt = self.bccx.cat_expr(arg);
+          self.guarantee_valid(arg.id, arg.span, arg_cmt, m_imm, scope_r);
+          visit::visit_expr(ex, self, vt);
       }
 
-      // FIXME--#3387
-      // ast::expr_binary(_, lhs, rhs) => {
-      //     // Universal comparison operators like ==, >=, etc
-      //     // take their arguments by reference.
-      //     let lhs_ty = ty::expr_ty(self.tcx(), lhs);
-      //     if !ty::type_is_scalar(lhs_ty) {
-      //         let scope_r = ty::re_scope(ex.id);
-      //         let lhs_cmt = self.bccx.cat_expr(lhs);
-      //         self.guarantee_valid(lhs_cmt, m_imm, scope_r);
-      //         let rhs_cmt = self.bccx.cat_expr(rhs);
-      //         self.guarantee_valid(rhs_cmt, m_imm, scope_r);
-      //     }
-      //     visit::visit_expr(ex, self, vt);
-      // }
-
       // see explanation attached to the `root_ub` field:
       ast::expr_while(cond, ref body) => {
           // during the condition, can only root for the condition
diff --git a/src/librustc/middle/typeck/check/regionck.rs b/src/librustc/middle/typeck/check/regionck.rs
index fd19738b321..1b0a22752a5 100644
--- a/src/librustc/middle/typeck/check/regionck.rs
+++ b/src/librustc/middle/typeck/check/regionck.rs
@@ -236,9 +236,16 @@ fn visit_expr(expr: @ast::expr, rcx: @mut Rcx, v: rvt) {
     // overloaded.  See #3511.
     let tcx = rcx.fcx.tcx();
     match expr.node {
+        // You'd think that x += y where `+=` is overloaded would be a
+        // cleanup scope. You'd be... kind of right. In fact the
+        // handling of `+=` and friends in trans for overloaded
+        // operators is a hopeless mess and I can't figure out how to
+        // represent it. - ndm
+        //
+        // ast::expr_assign_op(*) |
+
         ast::expr_index(*) |
         ast::expr_binary(*) |
-        ast::expr_assign_op(*) |
         ast::expr_unary(*) if has_method_map => {
             tcx.region_maps.record_cleanup_scope(expr.id);
         }
diff --git a/src/libstd/arc.rs b/src/libstd/arc.rs
index 027bf93b481..98d7a01b928 100644
--- a/src/libstd/arc.rs
+++ b/src/libstd/arc.rs
@@ -598,8 +598,8 @@ mod tests {
         let arc = ~RWARC(1);
         let arc2 = (*arc).clone();
         do task::try || {
-            do arc2.write_downgrade |write_mode| {
-                do (&write_mode).write |one| {
+            do arc2.write_downgrade |mut write_mode| {
+                do write_mode.write |one| {
                     assert!(*one == 2);
                 }
             }
@@ -733,8 +733,8 @@ mod tests {
         }
 
         // Downgrader (us)
-        do arc.write_downgrade |write_mode| {
-            do (&write_mode).write_cond |state, cond| {
+        do arc.write_downgrade |mut write_mode| {
+            do write_mode.write_cond |state, cond| {
                 wc1.send(()); // send to another writer who will wake us up
                 while *state == 0 {
                     cond.wait();
diff --git a/src/libstd/rope.rs b/src/libstd/rope.rs
index 1292d2a8585..93364f8a319 100644
--- a/src/libstd/rope.rs
+++ b/src/libstd/rope.rs
@@ -1256,22 +1256,24 @@ mod tests {
         match (r) {
           node::Empty => return ~"",
           node::Content(x) => {
-            let str = @mut ~"";
-            fn aux(str: @mut ~str, node: @node::Node) {
+            let mut str = ~"";
+            fn aux(str: &mut ~str, node: @node::Node) {
                 match (*node) {
-                  node::Leaf(x) => {
-                    *str += str::slice(
-                        *x.content, x.byte_offset,
-                        x.byte_offset + x.byte_len).to_owned();
-                  }
-                  node::Concat(ref x) => {
-                    aux(str, x.left);
-                    aux(str, x.right);
-                  }
+                    node::Leaf(x) => {
+                        str::push_str(
+                            str,
+                            str::slice(
+                                *x.content, x.byte_offset,
+                                x.byte_offset + x.byte_len));
+                    }
+                    node::Concat(ref x) => {
+                        aux(str, x.left);
+                        aux(str, x.right);
+                    }
                 }
             }
-            aux(str, x);
-            return *str
+            aux(&mut str, x);
+            return str
           }
         }
     }
diff --git a/src/libstd/sort.rs b/src/libstd/sort.rs
index f3d30ecd5cd..119b47c904e 100644
--- a/src/libstd/sort.rs
+++ b/src/libstd/sort.rs
@@ -22,12 +22,12 @@ type Le<'self, T> = &'self fn(v1: &T, v2: &T) -> bool;
  * Has worst case O(n log n) performance, best case O(n), but
  * is not space efficient. This is a stable sort.
  */
-pub fn merge_sort<T:Copy>(v: &const [T], le: Le<T>) -> ~[T] {
+pub fn merge_sort<T:Copy>(v: &[T], le: Le<T>) -> ~[T] {
     type Slice = (uint, uint);
 
     return merge_sort_(v, (0u, len(v)), le);
 
-    fn merge_sort_<T:Copy>(v: &const [T], slice: Slice, le: Le<T>)
+    fn merge_sort_<T:Copy>(v: &[T], slice: Slice, le: Le<T>)
         -> ~[T] {
         let begin = slice.first();
         let end = slice.second();
@@ -179,7 +179,7 @@ fn qsort3<T:Copy + Ord + Eq>(arr: &mut [T], left: int, right: int) {
  */
 pub fn quick_sort3<T:Copy + Ord + Eq>(arr: &mut [T]) {
     if arr.len() <= 1 { return; }
-    let len = arr.len() - 1; // FIXME(#5074) nested calls
+    let len = arr.len(); // FIXME(#5074) nested calls
     qsort3(arr, 0, (len - 1) as int);
 }
 
@@ -263,7 +263,7 @@ fn binarysort<T:Copy + Ord>(array: &mut [T], start: uint) {
         assert!(left == right);
         let n = start-left;
 
-        copy_vec(array, left+1, array, left, n);
+        shift_vec(array, left+1, left, n);
         array[left] = pivot;
         start += 1;
     }
@@ -309,8 +309,8 @@ fn count_run_ascending<T:Copy + Ord>(array: &mut [T]) -> uint {
     return run;
 }
 
-fn gallop_left<T:Copy + Ord>(key: &const T,
-                             array: &const [T],
+fn gallop_left<T:Copy + Ord>(key: &T,
+                             array: &[T],
                              hint: uint)
                           -> uint {
     let size = array.len();
@@ -360,8 +360,8 @@ fn gallop_left<T:Copy + Ord>(key: &const T,
     return ofs;
 }
 
-fn gallop_right<T:Copy + Ord>(key: &const T,
-                              array: &const [T],
+fn gallop_right<T:Copy + Ord>(key: &T,
+                              array: &[T],
                               hint: uint)
                            -> uint {
     let size = array.len();
@@ -457,15 +457,15 @@ impl<T:Copy + Ord> MergeState<T> {
         }
 
         let k = { // constrain lifetime of slice below
-            let slice = vec::mut_slice(array, b1, b1+l1);
-            gallop_right(&const array[b2], slice, 0)
+            let slice = vec::slice(array, b1, b1+l1);
+            gallop_right(&array[b2], slice, 0)
         };
         b1 += k;
         l1 -= k;
         if l1 != 0 {
             let l2 = { // constrain lifetime of slice below
-                let slice = vec::mut_slice(array, b2, b2+l2);
-                gallop_left(&const array[b1+l1-1],slice,l2-1)
+                let slice = vec::slice(array, b2, b2+l2);
+                gallop_left(&array[b1+l1-1],slice,l2-1)
             };
             if l2 > 0 {
                 if l1 <= l2 {
@@ -497,11 +497,11 @@ impl<T:Copy + Ord> MergeState<T> {
         dest += 1; c2 += 1; len2 -= 1;
 
         if len2 == 0 {
-            copy_vec(array, dest, tmp, 0, len1);
+            copy_vec(array, dest, tmp.slice(0, len1));
             return;
         }
         if len1 == 1 {
-            copy_vec(array, dest, array, c2, len2);
+            shift_vec(array, dest, c2, len2);
             array[dest+len2] <-> tmp[c1];
             return;
         }
@@ -539,10 +539,12 @@ impl<T:Copy + Ord> MergeState<T> {
             loop {
                 assert!(len1 > 1 && len2 != 0);
 
-                let tmp_view = vec::const_slice(tmp, c1, c1+len1);
-                count1 = gallop_right(&const array[c2], tmp_view, 0);
+                count1 = {
+                    let tmp_view = vec::slice(tmp, c1, c1+len1);
+                    gallop_right(&array[c2], tmp_view, 0)
+                };
                 if count1 != 0 {
-                    copy_vec(array, dest, tmp, c1, count1);
+                    copy_vec(array, dest, tmp.slice(c1, c1+count1));
                     dest += count1; c1 += count1; len1 -= count1;
                     if len1 <= 1 { break_outer = true; break; }
                 }
@@ -550,10 +552,12 @@ impl<T:Copy + Ord> MergeState<T> {
                 dest += 1; c2 += 1; len2 -= 1;
                 if len2 == 0 { break_outer = true; break; }
 
-                let tmp_view = vec::const_slice(array, c2, c2+len2);
-                count2 = gallop_left(&const tmp[c1], tmp_view, 0);
+                count2 = {
+                    let tmp_view = vec::slice(array, c2, c2+len2);
+                    gallop_left(&tmp[c1], tmp_view, 0)
+                };
                 if count2 != 0 {
-                    copy_vec(array, dest, array, c2, count2);
+                    shift_vec(array, dest, c2, count2);
                     dest += count2; c2 += count2; len2 -= count2;
                     if len2 == 0 { break_outer = true; break; }
                 }
@@ -573,14 +577,14 @@ impl<T:Copy + Ord> MergeState<T> {
 
         if len1 == 1 {
             assert!(len2 > 0);
-            copy_vec(array, dest, array, c2, len2);
+            shift_vec(array, dest, c2, len2);
             array[dest+len2] <-> tmp[c1];
         } else if len1 == 0 {
             fail!(~"Comparison violates its contract!");
         } else {
             assert!(len2 == 0);
             assert!(len1 > 1);
-            copy_vec(array, dest, tmp, c1, len1);
+            copy_vec(array, dest, tmp.slice(c1, c1+len1));
         }
     }
 
@@ -603,13 +607,13 @@ impl<T:Copy + Ord> MergeState<T> {
         dest -= 1; c1 -= 1; len1 -= 1;
 
         if len1 == 0 {
-            copy_vec(array, dest-(len2-1), tmp, 0, len2);
+            copy_vec(array, dest-(len2-1), tmp.slice(0, len2));
             return;
         }
         if len2 == 1 {
             dest -= len1;
             c1 -= len1;
-            copy_vec(array, dest+1, array, c1+1, len1);
+            shift_vec(array, dest+1, c1+1, len1);
             array[dest] <-> tmp[c2];
             return;
         }
@@ -650,12 +654,12 @@ impl<T:Copy + Ord> MergeState<T> {
                 { // constrain scope of tmp_view:
                     let tmp_view = vec::mut_slice (array, base1, base1+len1);
                     count1 = len1 - gallop_right(
-                        &const tmp[c2], tmp_view, len1-1);
+                        &tmp[c2], tmp_view, len1-1);
                 }
 
                 if count1 != 0 {
                     dest -= count1; c1 -= count1; len1 -= count1;
-                    copy_vec(array, dest+1, array, c1+1, count1);
+                    shift_vec(array, dest+1, c1+1, count1);
                     if len1 == 0 { break_outer = true; break; }
                 }
 
@@ -666,14 +670,14 @@ impl<T:Copy + Ord> MergeState<T> {
                 let count2;
                 { // constrain scope of tmp_view
                     let tmp_view = vec::mut_slice(tmp, 0, len2);
-                    count2 = len2 - gallop_left(&const array[c1],
+                    count2 = len2 - gallop_left(&array[c1],
                                                 tmp_view,
                                                 len2-1);
                 }
 
                 if count2 != 0 {
                     dest -= count2; c2 -= count2; len2 -= count2;
-                    copy_vec(array, dest+1, tmp, c2+1, count2);
+                    copy_vec(array, dest+1, tmp.slice(c2+1, c2+1+count2));
                     if len2 <= 1 { break_outer = true; break; }
                 }
                 array[dest] <-> array[c1];
@@ -695,14 +699,14 @@ impl<T:Copy + Ord> MergeState<T> {
             assert!(len1 > 0);
             dest -= len1;
             c1 -= len1;
-            copy_vec(array, dest+1, array, c1+1, len1);
+            shift_vec(array, dest+1, c1+1, len1);
             array[dest] <-> tmp[c2];
         } else if len2 == 0 {
             fail!(~"Comparison violates its contract!");
         } else {
             assert!(len1 == 0);
             assert!(len2 != 0);
-            copy_vec(array, dest-(len2-1), tmp, 0, len2);
+            copy_vec(array, dest-(len2-1), tmp.slice(0, len2));
         }
     }
 
@@ -738,21 +742,25 @@ impl<T:Copy + Ord> MergeState<T> {
 #[inline(always)]
 fn copy_vec<T:Copy>(dest: &mut [T],
                     s1: uint,
-                    from: &const [T],
-                    s2: uint,
-                    len: uint) {
-    assert!(s1+len <= dest.len() && s2+len <= from.len());
-
-    let mut slice = ~[];
-    for uint::range(s2, s2+len) |i| {
-        slice.push(from[i]);
-    }
+                    from: &[T]) {
+    assert!(s1+from.len() <= dest.len());
 
-    for slice.eachi |i, v| {
+    for from.eachi |i, v| {
         dest[s1+i] = *v;
     }
 }
 
+#[inline(always)]
+fn shift_vec<T:Copy>(dest: &mut [T],
+                     s1: uint,
+                     s2: uint,
+                     len: uint) {
+    assert!(s1+len <= dest.len());
+
+    let tmp = dest.slice(s2, s2+len).to_vec();
+    copy_vec(dest, s1, tmp);
+}
+
 #[cfg(test)]
 mod test_qsort3 {
     use sort::*;
@@ -764,8 +772,7 @@ mod test_qsort3 {
         quick_sort3::<int>(v1);
         let mut i = 0;
         while i < len {
-            // debug!(v2[i]);
-            assert!((v2[i] == v1[i]));
+            assert_eq!(v2[i], v1[i]);
             i += 1;
         }
     }
@@ -1036,7 +1043,7 @@ mod big_tests {
         tabulate_managed(low, high);
     }
 
-    fn multiplyVec<T:Copy>(arr: &const [T], num: uint) -> ~[T] {
+    fn multiplyVec<T:Copy>(arr: &[T], num: uint) -> ~[T] {
         let size = arr.len();
         let res = do vec::from_fn(num) |i| {
             arr[i % size]
@@ -1052,7 +1059,7 @@ mod big_tests {
     }
 
     fn tabulate_unique(lo: uint, hi: uint) {
-        fn isSorted<T:Ord>(arr: &const [T]) {
+        fn isSorted<T:Ord>(arr: &[T]) {
             for uint::range(0, arr.len()-1) |i| {
                 if arr[i] > arr[i+1] {
                     fail!(~"Array not sorted");
@@ -1123,7 +1130,7 @@ mod big_tests {
     }
 
     fn tabulate_managed(lo: uint, hi: uint) {
-        fn isSorted<T:Ord>(arr: &const [@T]) {
+        fn isSorted<T:Ord>(arr: &[@T]) {
             for uint::range(0, arr.len()-1) |i| {
                 if arr[i] > arr[i+1] {
                     fail!(~"Array not sorted");
diff --git a/src/libstd/std.rc b/src/libstd/std.rc
index d9af8b111bb..9d1ddb8ec54 100644
--- a/src/libstd/std.rc
+++ b/src/libstd/std.rc
@@ -69,7 +69,14 @@ pub mod list;
 pub mod priority_queue;
 pub mod rope;
 pub mod smallintmap;
+
+#[cfg(stage0)]
+#[path="sort_stage0.rs"]
+pub mod sort;
+
+#[cfg(not(stage0))]
 pub mod sort;
+
 pub mod dlist;
 pub mod treemap;
 
diff --git a/src/test/compile-fail/borrowck-loan-in-overloaded-op.rs b/src/test/compile-fail/borrowck-loan-in-overloaded-op.rs
index 482d1b6b8b6..0361213af22 100644
--- a/src/test/compile-fail/borrowck-loan-in-overloaded-op.rs
+++ b/src/test/compile-fail/borrowck-loan-in-overloaded-op.rs
@@ -8,18 +8,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// xfail-test #3387
-
 struct foo(~uint);
 
 impl Add<foo, foo> for foo {
-    fn add(f: &foo) -> foo {
-        foo(~(**self + **(*f)))
+    fn add(&self, f: &foo) -> foo {
+        foo(~(***self + **(*f)))
     }
 }
 
 fn main() {
     let x = foo(~3);
-    let _y = x + x;
-    //~^ ERROR moving out of immutable local variable prohibited due to outstanding loan
+    let _y = x + {x}; // the `{x}` forces a move to occur
+    //~^ ERROR cannot move out of `x`
 }
diff --git a/src/test/run-pass/auto-ref-slice-plus-ref.rs b/src/test/run-pass/auto-ref-slice-plus-ref.rs
index 1dc56132875..07629651e56 100644
--- a/src/test/run-pass/auto-ref-slice-plus-ref.rs
+++ b/src/test/run-pass/auto-ref-slice-plus-ref.rs
@@ -17,13 +17,13 @@ trait MyIter {
 }
 
 impl<'self> MyIter for &'self [int] {
-    fn test_imm(&self) { assert!(self[0] == 1) }
-    fn test_const(&const self) { assert!(self[0] == 1) }
+    fn test_imm(&self) { assert_eq!(self[0], 1) }
+    fn test_const(&const self) { assert_eq!(self[0], 1) }
 }
 
 impl<'self> MyIter for &'self str {
-    fn test_imm(&self) { assert!(*self == "test") }
-    fn test_const(&const self) { assert!(*self == "test") }
+    fn test_imm(&self) { assert_eq!(*self, "test") }
+    fn test_const(&const self) { assert_eq!(self[0], 't') }
 }
 
 pub fn main() {