use rustc_data_structures::sync::{AtomicU32, Lrc, MappedReadGuard, ReadGuard, RwLock};
use std::cmp;
use std::hash::Hash;
-use std::path::{Path, PathBuf};
+use std::path::{self, Path, PathBuf};
use std::sync::atomic::Ordering;
use std::fs;
pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
source_file.add_external_src(|| {
- match source_file.name {
- FileName::Real(ref name) if let Some(local_path) = name.local_path() => {
- self.file_loader.read_file(local_path).ok()
+ let FileName::Real(ref name) = source_file.name else {
+ return None;
+ };
+
+ let local_path: Cow<'_, Path> = match name {
+ RealFileName::LocalPath(local_path) => local_path.into(),
+ RealFileName::Remapped { local_path: Some(local_path), .. } => local_path.into(),
+ RealFileName::Remapped { local_path: None, virtual_name } => {
+ // The compiler produces better error messages if the sources of dependencies
+ // are available. Attempt to undo any path mapping so we can find remapped
+ // dependencies.
+ // We can only use the heuristic because `add_external_src` checks the file
+ // content hash.
+ self.path_mapping.reverse_map_prefix_heuristically(virtual_name)?.into()
}
- _ => None,
- }
+ };
+
+ self.file_loader.read_file(&local_path).ok()
})
}
}
}
}
+
+ /// Attempts to (heuristically) reverse a prefix mapping.
+ ///
+ /// Returns [`Some`] if there is exactly one mapping where the "to" part is
+ /// a prefix of `path` and has at least one non-empty
+ /// [`Normal`](path::Component::Normal) component. The component
+ /// restriction exists to avoid reverse mapping overly generic paths like
+ /// `/` or `.`).
+ ///
+ /// This is a heuristic and not guaranteed to return the actual original
+ /// path! Do not rely on the result unless you have other means to verify
+ /// that the mapping is correct (e.g. by checking the file content hash).
+ #[instrument(level = "debug", skip(self), ret)]
+ fn reverse_map_prefix_heuristically(&self, path: &Path) -> Option<PathBuf> {
+ let mut found = None;
+
+ for (from, to) in self.mapping.iter() {
+ let has_normal_component = to.components().any(|c| match c {
+ path::Component::Normal(s) => !s.is_empty(),
+ _ => false,
+ });
+
+ if !has_normal_component {
+ continue;
+ }
+
+ let Ok(rest) = path.strip_prefix(to) else {
+ continue;
+ };
+
+ if found.is_some() {
+ return None;
+ }
+
+ found = Some(from.join(rest));
+ }
+
+ found
+ }
}