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Merge #9941
9941: feat: include full path in the cyclic deps error r=matklad a=matklad
bors r+
🤖
Co-authored-by: Aleksey Kladov <[email protected]>
| -rw-r--r-- | crates/base_db/src/input.rs | 57 |
1 files changed, 42 insertions, 15 deletions
diff --git a/crates/base_db/src/input.rs b/crates/base_db/src/input.rs index 3abe570336..671039e46b 100644 --- a/crates/base_db/src/input.rs +++ b/crates/base_db/src/input.rs @@ -247,12 +247,17 @@ impl CrateGraph { to: CrateId, ) -> Result<(), CyclicDependenciesError> { let _p = profile::span("add_dep"); - if self.dfs_find(from, to, &mut FxHashSet::default()) { - return Err(CyclicDependenciesError { - from: (from, self[from].display_name.clone()), - to: (to, self[to].display_name.clone()), - }); + + // Check if adding a dep from `from` to `to` creates a cycle. To figure + // that out, look for a path in the *opposite* direction, from `to` to + // `from`. + if let Some(path) = self.find_path(&mut FxHashSet::default(), to, from) { + let path = path.into_iter().map(|it| (it, self[it].display_name.clone())).collect(); + let err = CyclicDependenciesError { path }; + assert!(err.from().0 == from && err.to().0 == to); + return Err(err); } + self.arena.get_mut(&from).unwrap().add_dep(name, to); Ok(()) } @@ -361,22 +366,29 @@ impl CrateGraph { start } - fn dfs_find(&self, target: CrateId, from: CrateId, visited: &mut FxHashSet<CrateId>) -> bool { + fn find_path( + &self, + visited: &mut FxHashSet<CrateId>, + from: CrateId, + to: CrateId, + ) -> Option<Vec<CrateId>> { if !visited.insert(from) { - return false; + return None; } - if target == from { - return true; + if from == to { + return Some(vec![to]); } for dep in &self[from].dependencies { let crate_id = dep.crate_id; - if self.dfs_find(target, crate_id, visited) { - return true; + if let Some(mut path) = self.find_path(visited, crate_id, to) { + path.push(from); + return Some(path); } } - false + + None } // Work around for https://github.com/rust-analyzer/rust-analyzer/issues/6038. @@ -481,8 +493,16 @@ impl std::error::Error for ParseEditionError {} #[derive(Debug)] pub struct CyclicDependenciesError { - from: (CrateId, Option<CrateDisplayName>), - to: (CrateId, Option<CrateDisplayName>), + path: Vec<(CrateId, Option<CrateDisplayName>)>, +} + +impl CyclicDependenciesError { + fn from(&self) -> &(CrateId, Option<CrateDisplayName>) { + self.path.first().unwrap() + } + fn to(&self) -> &(CrateId, Option<CrateDisplayName>) { + self.path.last().unwrap() + } } impl fmt::Display for CyclicDependenciesError { @@ -491,7 +511,14 @@ impl fmt::Display for CyclicDependenciesError { Some(it) => format!("{}({:?})", it, id), None => format!("{:?}", id), }; - write!(f, "cyclic deps: {} -> {}", render(&self.from), render(&self.to)) + let path = self.path.iter().rev().map(render).collect::<Vec<String>>().join(" -> "); + write!( + f, + "cyclic deps: {} -> {}, alternative path: {}", + render(&self.from()), + render(&self.to()), + path + ) } } |