update_extern_crate belongs to CrateMetadata

This also allows us to make extern_crate field private

src/librustc_metadata/creader.rs

@@ -18,7 +18,7 @@ use rustc::hir::map::Definitions;
 use rustc::hir::def_id::LOCAL_CRATE;
 
 use std::path::Path;
-use std::{cmp, fs};
+use std::fs;
 
 use syntax::ast;
 use syntax::attr;
@@ -412,47 +412,6 @@ impl<'a> CrateLoader<'a> {
         }
     }
 
-    fn update_extern_crate(&self,
-                           cnum: CrateNum,
-                           mut extern_crate: ExternCrate,
-                           visited: &mut FxHashSet<(CrateNum, bool)>)
-    {
-        if !visited.insert((cnum, extern_crate.is_direct())) { return }
-
-        let cmeta = self.cstore.get_crate_data(cnum);
-        let mut old_extern_crate = cmeta.extern_crate.borrow_mut();
-
-        // Prefer:
-        // - something over nothing (tuple.0);
-        // - direct extern crate to indirect (tuple.1);
-        // - shorter paths to longer (tuple.2).
-        let new_rank = (
-            true,
-            extern_crate.is_direct(),
-            cmp::Reverse(extern_crate.path_len),
-        );
-        let old_rank = match *old_extern_crate {
-            None => (false, false, cmp::Reverse(usize::max_value())),
-            Some(ref c) => (
-                true,
-                c.is_direct(),
-                cmp::Reverse(c.path_len),
-            ),
-        };
-        if old_rank >= new_rank {
-            return; // no change needed
-        }
-
-        *old_extern_crate = Some(extern_crate);
-        drop(old_extern_crate);
-
-        // Propagate the extern crate info to dependencies.
-        extern_crate.dependency_of = cnum;
-        for &dep_cnum in cmeta.dependencies.borrow().iter() {
-            self.update_extern_crate(dep_cnum, extern_crate, visited);
-        }
-    }
-
     // Go through the crate metadata and load any crates that it references
     fn resolve_crate_deps(&mut self,
                           root: &CratePaths,
@@ -889,7 +848,9 @@ impl<'a> CrateLoader<'a> {
 
                 let def_id = definitions.opt_local_def_id(item.id).unwrap();
                 let path_len = definitions.def_path(def_id.index).data.len();
-                self.update_extern_crate(
+
+                let cmeta = self.cstore.get_crate_data(cnum);
+                cmeta.update_extern_crate(
                     cnum,
                     ExternCrate {
                         src: ExternCrateSource::Extern(def_id),
@@ -908,7 +869,8 @@ impl<'a> CrateLoader<'a> {
     pub fn process_path_extern(&mut self, name: Symbol, span: Span) -> CrateNum {
         let cnum = self.resolve_crate(name, span, DepKind::Explicit, None);
 
-        self.update_extern_crate(
+        let cmeta = self.cstore.get_crate_data(cnum);
+        cmeta.update_extern_crate(
             cnum,
             ExternCrate {
                 src: ExternCrateSource::Path,
@@ -926,7 +888,8 @@ impl<'a> CrateLoader<'a> {
     pub fn maybe_process_path_extern(&mut self, name: Symbol, span: Span) -> Option<CrateNum> {
         let cnum = self.maybe_resolve_crate(name, span, DepKind::Explicit, None).ok()?;
 
-        self.update_extern_crate(
+        let cmeta = self.cstore.get_crate_data(cnum);
+        cmeta.update_extern_crate(
             cnum,
             ExternCrate {
                 src: ExternCrateSource::Path,

src/librustc_metadata/cstore.rs

@@ -16,7 +16,7 @@ use rustc::middle::cstore::{
 use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
 use rustc::mir::{Body, Promoted};
 use rustc::mir::interpret::AllocDecodingState;
-use rustc::util::nodemap::FxHashMap;
+use rustc::util::nodemap::{FxHashMap, FxHashSet};
 use rustc::session::Session;
 use rustc::ty::{self, Ty, TyCtxt};
 use rustc_data_structures::sync::{Lrc, Lock, MetadataRef, Once, AtomicCell};
@@ -110,7 +110,7 @@ crate struct CrateMetadata {
 
     /// Information about the `extern crate` item or path that caused this crate to be loaded.
     /// If this is `None`, then the crate was injected (e.g., by the allocator).
-    crate extern_crate: Lock<Option<ExternCrate>>,
+    extern_crate: Lock<Option<ExternCrate>>,
 }
 
 impl<'a, 'tcx> CrateMetadata {
@@ -464,6 +464,61 @@ impl<'a, 'tcx> CrateMetadata {
         });
     }
 
+    crate fn get_extern_crate_arenas(&self, tcx: TyCtxt<'tcx>) -> Option<&'tcx ExternCrate> {
+        let r = *self.extern_crate.lock();
+        r.map(|c| &*tcx.arena.alloc(c))
+    }
+
+    crate fn is_extern_crate_direct(&self) -> bool {
+        match *self.extern_crate.borrow() {
+            Some(extern_crate) if !extern_crate.is_direct() => true,
+            _ => false,
+        }
+    }
+
+    // let cmeta = self.cstore.get_crate_data(cnum);
+    crate fn update_extern_crate(
+        &self,
+        cnum: CrateNum,
+        mut extern_crate: ExternCrate,
+        visited: &mut FxHashSet<(CrateNum, bool)>,
+    ) {
+        if !visited.insert((cnum, extern_crate.is_direct())) { return }
+
+        let mut old_extern_crate = self.extern_crate.borrow_mut();
+
+        // Prefer:
+        // - something over nothing (tuple.0);
+        // - direct extern crate to indirect (tuple.1);
+        // - shorter paths to longer (tuple.2).
+        let new_rank = (
+            true,
+            extern_crate.is_direct(),
+            cmp::Reverse(extern_crate.path_len),
+        );
+        let old_rank = match *old_extern_crate {
+            None => (false, false, cmp::Reverse(usize::max_value())),
+            Some(ref c) => (
+                true,
+                c.is_direct(),
+                cmp::Reverse(c.path_len),
+            ),
+        };
+        if old_rank >= new_rank {
+            return; // no change needed
+        }
+
+        *old_extern_crate = Some(extern_crate);
+        drop(old_extern_crate);
+
+        // Propagate the extern crate info to dependencies.
+        extern_crate.dependency_of = cnum;
+        for &dep_cnum in self.dependencies.borrow().iter() {
+            self.update_extern_crate(dep_cnum, extern_crate, visited);
+        }
+    }
+
+
     /// Iterates over the diagnostic items in the given crate.
     crate fn get_diagnostic_items(
         &self,

src/librustc_metadata/cstore_impl.rs

@@ -160,10 +160,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     is_sanitizer_runtime => { cdata.root.sanitizer_runtime }
     is_profiler_runtime => { cdata.root.profiler_runtime }
     panic_strategy => { cdata.root.panic_strategy }
-    extern_crate => {
-        let r = *cdata.extern_crate.lock();
-        r.map(|c| &*tcx.arena.alloc(c))
-    }
+    extern_crate => { cdata.get_extern_crate_arenas(tcx) }
     is_no_builtins => { cdata.root.no_builtins }
     symbol_mangling_version => { cdata.root.symbol_mangling_version }
     impl_defaultness => { cdata.get_impl_defaultness(def_id.index) }
@@ -223,13 +220,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     diagnostic_items => { cdata.get_diagnostic_items(tcx) }
     missing_lang_items => { cdata.get_missing_lang_items(tcx) }
 
-    missing_extern_crate_item => {
-        let r = match *cdata.extern_crate.borrow() {
-            Some(extern_crate) if !extern_crate.is_direct() => true,
-            _ => false,
-        };
-        r
-    }
+    missing_extern_crate_item => { cdata.is_extern_crate_direct() }
 
     used_crate_source => { Lrc::new(cdata.source.clone()) }