Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/load-cargo/src/lib.rs')
| -rw-r--r-- | crates/load-cargo/src/lib.rs | 84 |
1 files changed, 63 insertions, 21 deletions
diff --git a/crates/load-cargo/src/lib.rs b/crates/load-cargo/src/lib.rs index cb785195a0..de68b86714 100644 --- a/crates/load-cargo/src/lib.rs +++ b/crates/load-cargo/src/lib.rs @@ -285,28 +285,54 @@ impl SourceRootConfig { /// If a `SourceRoot` doesn't have a parent and is local then it is not contained in this mapping but it can be asserted that it is a root `SourceRoot`. pub fn source_root_parent_map(&self) -> FxHashMap<SourceRootId, SourceRootId> { let roots = self.fsc.roots(); - roots - .iter() - .enumerate() - .filter(|(_, (_, id))| self.local_filesets.contains(id)) - .filter_map(|(idx, (root, root_id))| { - // We are interested in parents if they are also local source roots. - // So instead of a non-local parent we may take a local ancestor as a parent to a node. - // - // Here paths in roots are sorted lexicographically, so if a root - // is a parent of another root, it will be before it in the list. - roots[..idx].iter().find_map(|(root2, root2_id)| { - if self.local_filesets.contains(root2_id) - && root.starts_with(root2) - && root_id != root2_id - { - return Some((root_id, root2_id)); + + let mut map = FxHashMap::default(); + + // See https://github.com/rust-lang/rust-analyzer/issues/17409 + // + // We can view the connections between roots as a graph. The problem is + // that this graph may contain cycles, so when adding edges, it is necessary + // to check whether it will lead to a cycle. + // + // Since we ensure that each node has at most one outgoing edge (because + // each SourceRoot can have only one parent), we can use a disjoint-set to + // maintain the connectivity between nodes. If an edge’s two nodes belong + // to the same set, they are already connected. + let mut dsu = FxHashMap::default(); + fn find_parent(dsu: &mut FxHashMap<u64, u64>, id: u64) -> u64 { + if let Some(&parent) = dsu.get(&id) { + let parent = find_parent(dsu, parent); + dsu.insert(id, parent); + parent + } else { + id + } + } + + for (idx, (root, root_id)) in roots.iter().enumerate() { + if !self.local_filesets.contains(root_id) + || map.contains_key(&SourceRootId(*root_id as u32)) + { + continue; + } + + for (root2, root2_id) in roots[..idx].iter().rev() { + if self.local_filesets.contains(root2_id) + && root_id != root2_id + && root.starts_with(root2) + { + // check if the edge will create a cycle + if find_parent(&mut dsu, *root_id) != find_parent(&mut dsu, *root2_id) { + map.insert(SourceRootId(*root_id as u32), SourceRootId(*root2_id as u32)); + dsu.insert(*root_id, *root2_id); } - None - }) - }) - .map(|(&child, &parent)| (SourceRootId(child as u32), SourceRootId(parent as u32))) - .collect() + + break; + } + } + } + + map } } @@ -592,4 +618,20 @@ mod tests { assert_eq!(vc, vec![(SourceRootId(1), SourceRootId(0)),]) } + + #[test] + fn circular_reference() { + let mut builder = FileSetConfigBuilder::default(); + builder.add_file_set(vec![ + VfsPath::new_virtual_path("/ROOT/def".to_owned()), + VfsPath::new_virtual_path("/ROOT/def/abc/def".to_owned()), + ]); + builder.add_file_set(vec![VfsPath::new_virtual_path("/ROOT/def/abc".to_owned())]); + let fsc = builder.build(); + let src = SourceRootConfig { fsc, local_filesets: vec![0, 1] }; + let mut vc = src.source_root_parent_map().into_iter().collect::<Vec<_>>(); + vc.sort_by(|x, y| x.0 .0.cmp(&y.0 .0)); + + assert_eq!(vc, vec![(SourceRootId(1), SourceRootId(0)),]) + } } |