Make init_locking return a reference to the initialized data

Author: spastorino

src/librustc_data_structures/sync.rs

@@ -497,13 +497,15 @@ impl<T> Once<T> {
  /// If the value was already initialized the closure is not called and `false` is returned,
  /// otherwise if the value from the closure initializes the inner value, `true` is returned
  #[inline]
- pub fn init_locking<F: FnOnce() -> T>(&self, f: F) -> bool {
- let mut lock = self.0.lock();
- if lock.is_some() {
- return false;
+ pub fn init_locking<F: FnOnce() -> T>(&self, f: F) -> &T {
+ {
+ let mut lock = self.0.lock();
+ if lock.is_none() {
+ *lock = Some(f());
+ }
  }
- *lock = Some(f());
- true
+
+ self.borrow()
  }
 
  /// Tries to initialize the inner value by calling the closure without ensuring that no-one

src/librustc_metadata/decoder.rs

@@ -1351,9 +1351,7 @@ impl<'a, 'tcx> CrateMetadata {
  translated_source_file: local_version,
  }
  }).collect()
- });
-
- self.source_map_import_info.borrow()
+ })
  }
 
  /// Get the `DepNodeIndex` corresponding this crate. The result of this