diff options
| -rw-r--r-- | src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs | 45 |
1 files changed, 24 insertions, 21 deletions
diff --git a/src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs b/src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs index 56643c6cbe8..d51e1109ed4 100644 --- a/src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs +++ b/src/tools/miri/src/borrow_tracker/tree_borrows/tree.rs @@ -754,29 +754,32 @@ impl Tree { // list of remaining children back in. let mut children_of_node = mem::take(&mut self.nodes.get_mut(*tag).unwrap().children); - // Remove all useless children, and save them for later. - // The closure needs `&self` and the loop below needs `&mut self`, so we need to `collect` - // in to a temporary list. - let to_remove: Vec<_> = - children_of_node.drain_filter(|x| self.is_useless(*x, live)).collect(); + // Remove all useless children. + children_of_node.retain_mut(|idx| { + if self.is_useless(*idx, live) { + // Note: In the rest of this comment, "this node" refers to `idx`. + // This node has no more children (if there were any, they have already been removed). + // It is also unreachable as determined by the GC, so we can remove it everywhere. + // Due to the API of UniMap we must make sure to call + // `UniValMap::remove` for the key of this node on *all* maps that used it + // (which are `self.nodes` and every range of `self.rperms`) + // before we can safely apply `UniKeyMap::remove` to truly remove + // this tag from the `tag_mapping`. + let node = self.nodes.remove(*idx).unwrap(); + for (_perms_range, perms) in self.rperms.iter_mut_all() { + perms.remove(*idx); + } + self.tag_mapping.remove(&node.tag); + // now delete it + false + } else { + // do nothing, but retain + true + } + }); // Put back the now-filtered vector. self.nodes.get_mut(*tag).unwrap().children = children_of_node; - // Now, all that is left is unregistering the children saved in `to_remove`. - for idx in to_remove { - // Note: In the rest of this comment, "this node" refers to `idx`. - // This node has no more children (if there were any, they have already been removed). - // It is also unreachable as determined by the GC, so we can remove it everywhere. - // Due to the API of UniMap we must make sure to call - // `UniValMap::remove` for the key of this node on *all* maps that used it - // (which are `self.nodes` and every range of `self.rperms`) - // before we can safely apply `UniKeyMap::remove` to truly remove - // this tag from the `tag_mapping`. - let node = self.nodes.remove(idx).unwrap(); - for (_perms_range, perms) in self.rperms.iter_mut_all() { - perms.remove(idx); - } - self.tag_mapping.remove(&node.tag); - } + // We are done, the parent can continue. stack.pop(); continue; |