rustc_metadata: Privatize CrateMetadata::dependencies

Author: petrochenkov

src/librustc_metadata/creader.rs

@@ -428,7 +428,7 @@ impl<'a> CrateLoader<'a> {
 
         // Propagate the extern crate info to dependencies.
         extern_crate.dependency_of = cnum;
-        for &dep_cnum in cmeta.dependencies.borrow().iter() {
+        for &dep_cnum in cmeta.dependencies().iter() {
             self.update_extern_crate(dep_cnum, extern_crate, visited);
         }
     }
@@ -829,7 +829,7 @@ impl<'a> CrateLoader<'a> {
             }
 
             info!("injecting a dep from {} to {}", cnum, krate);
-            data.dependencies.borrow_mut().push(krate);
+            data.add_dependency(krate);
         });
     }
 

src/librustc_metadata/cstore.rs

@@ -66,7 +66,7 @@ impl CStore {
     fn push_dependencies_in_postorder(&self, deps: &mut Vec<CrateNum>, cnum: CrateNum) {
         if !deps.contains(&cnum) {
             let data = self.get_crate_data(cnum);
-            for &dep in data.dependencies.borrow().iter() {
+            for &dep in data.dependencies().iter() {
                 if dep != cnum {
                     self.push_dependencies_in_postorder(deps, dep);
                 }

src/librustc_metadata/rmeta/decoder.rs

@@ -4,7 +4,7 @@ use crate::rmeta::*;
 use crate::rmeta::table::{FixedSizeEncoding, Table};
 
 use rustc_index::vec::{Idx, IndexVec};
-use rustc_data_structures::sync::{Lrc, Lock, Once, AtomicCell};
+use rustc_data_structures::sync::{Lrc, Lock, LockGuard, Once, AtomicCell};
 use rustc::hir::map::{DefKey, DefPath, DefPathData, DefPathHash};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc::hir;
@@ -97,7 +97,7 @@ crate struct CrateMetadata {
     /// IDs as they are seen from the current compilation session.
     cnum_map: CrateNumMap,
     /// Same ID set as `cnum_map` plus maybe some injected crates like panic runtime.
-    crate dependencies: Lock<Vec<CrateNum>>,
+    dependencies: Lock<Vec<CrateNum>>,
     /// How to link (or not link) this crate to the currently compiled crate.
     crate dep_kind: Lock<DepKind>,
     /// Filesystem location of this crate.
@@ -1517,6 +1517,14 @@ impl<'a, 'tcx> CrateMetadata {
 
         dep_node_index
     }
+
+    crate fn dependencies(&self) -> LockGuard<'_, Vec<CrateNum>> {
+        self.dependencies.borrow()
+    }
+
+    crate fn add_dependency(&self, cnum: CrateNum) {
+        self.dependencies.borrow_mut().push(cnum);
+    }
 }
 
 // Cannot be implemented on 'ProcMacro', as libproc_macro