use middle::dataflow::BitwiseOperator;
use middle::dataflow::DataFlowOperator;
use euv = middle::expr_use_visitor;
+use mc = middle::mem_categorization;
use middle::ty;
use syntax::ast;
use syntax::ast_util;
pub type AssignDataFlow<'a> = DataFlowContext<'a, AssignDataFlowOperator>;
+fn loan_path_is_precise(loan_path: &LoanPath) -> bool {
+ match *loan_path {
+ LpVar(_) => {
+ true
+ }
+ LpExtend(_, _, LpInterior(mc::InteriorElement(_))) => {
+ // Paths involving element accesses do not refer to a unique
+ // location, as there is no accurate tracking of the indices.
+ false
+ }
+ LpExtend(ref lp_base, _, _) => {
+ loan_path_is_precise(&**lp_base)
+ }
+ }
+}
+
impl MoveData {
pub fn new() -> MoveData {
MoveData {
path: MovePathIndex,
kill_id: ast::NodeId,
dfcx_moves: &mut MoveDataFlow) {
- self.each_applicable_move(path, |move_index| {
- dfcx_moves.add_kill(kill_id, move_index.get());
- true
- });
+ // We can only perform kills for paths that refer to a unique location,
+ // since otherwise we may kill a move from one location with an
+ // assignment referring to another location.
+
+ let loan_path = self.path_loan_path(path);
+ if loan_path_is_precise(&*loan_path) {
+ self.each_applicable_move(path, |move_index| {
+ dfcx_moves.add_kill(kill_id, move_index.get());
+ true
+ });
+ }
}
}
--- /dev/null
+// 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.
+
+fn f() {
+ let mut a = [box 0, box 1];
+ drop(a[0]);
+ a[1] = box 2;
+ drop(a[0]); //~ ERROR use of moved value: `a[..]`
+}
+
+fn main() {
+ f();
+}
+