9941: feat: include full path in the cyclic deps error r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
This commit is contained in:
bors[bot] 2021-08-18 12:36:18 +00:00 committed by GitHub
commit 320bb72b7f
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@ -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
)
}
}