2 files changed, 38 insertions, 22 deletions
diff --git a/clang/include/clang/Serialization/GlobalModuleIndex.h b/clang/include/clang/Serialization/GlobalModuleIndex.h
index 703025ea2e7..38ccb26970f 100644
--- a/clang/include/clang/Serialization/GlobalModuleIndex.h
+++ b/clang/include/clang/Serialization/GlobalModuleIndex.h
@@ -93,9 +93,6 @@ class GlobalModuleIndex {
   /// identifier.
   unsigned NumIdentifierLookupHits;
 
-  /// \brief The number of modules provided via skip sets.
-  unsigned NumIdentifierModulesSkipped;
-
   /// \brief Internal constructor. Use \c readIndex() to read an index.
   explicit GlobalModuleIndex(FileManager &FileMgr, llvm::MemoryBuffer *Buffer,
                              llvm::BitstreamCursor Cursor);
@@ -142,31 +139,20 @@ public:
   void getModuleDependencies(const FileEntry *ModuleFile,
                              SmallVectorImpl<const FileEntry *> &Dependencies);
 
+  /// \brief A set of module files in which we found a result.
+  typedef llvm::SmallPtrSet<const FileEntry *, 4> HitSet;
+  
   /// \brief Look for all of the module files with a namespace-scope binding
   /// for the given identifier, e.g., a global function, variable, or type with
   /// that name, or declare a method with the selector.
   ///
   /// \param Name The identifier to look for.
   ///
-  /// \param ModuleFiles Will be populated with the list of module
+  /// \param Hits Will be populated with the set of module
   /// files that declare entities with the given name.
   ///
-  /// \returns true if any module files were found, false otherwise.
-  bool lookupIdentifier(StringRef Name,
-                        SmallVectorImpl<const FileEntry *> &ModuleFiles);
-
-  /// \brief A set of module files into which name lookup can be skipped,
-  /// because they are known not to contain any bindings for the given name.
-  typedef llvm::SmallPtrSet<const FileEntry *, 16> SkipSet;
-
-  /// \brief Compute the "skip set", meaning those known modules that do not
-  /// have some particular property.
-  ///
-  /// \param ModuleFiles The set of module files that has some property.
-  ///
-  /// \returns The set of known modules that do not have the property exhibited
-  /// by the files in \p ModuleFiles.
-  SkipSet computeSkipSet(const SmallVectorImpl<const FileEntry *> &ModuleFiles);
+  /// \returns true if the identifier is known to the index, false otherwise.
+  bool lookupIdentifier(StringRef Name, HitSet &Hits);
 
   /// \brief Print statistics to standard error.
   void printStats();
diff --git a/clang/include/clang/Serialization/ModuleManager.h b/clang/include/clang/Serialization/ModuleManager.h
index 465da767879..05d702664e8 100644
--- a/clang/include/clang/Serialization/ModuleManager.h
+++ b/clang/include/clang/Serialization/ModuleManager.h
@@ -21,6 +21,8 @@
 
 namespace clang { 
 
+class GlobalModuleIndex;
+
 namespace serialization {
   
 /// \brief Manages the set of modules loaded by an AST reader.
@@ -42,6 +44,25 @@ class ModuleManager {
   /// \brief The visitation order.
   SmallVector<ModuleFile *, 4> VisitOrder;
 
+  /// \brief The list of module files that both we and the global module index
+  /// know about.
+  ///
+  /// Either the global index or the module manager may have modules that the
+  /// other does not know about, because the global index can be out-of-date
+  /// (in which case the module manager could have modules it does not) and
+  /// this particular translation unit might not have loaded all of the modules
+  /// known to the global index.
+  SmallVector<ModuleFile *, 4> ModulesInCommonWithGlobalIndex;
+
+  /// \brief The global module index, if one is attached.
+  ///
+  /// The global module index will actually be owned by the ASTReader; this is
+  /// just an non-owning pointer.
+  GlobalModuleIndex *GlobalIndex;
+
+  /// \brief Update the set of modules files we know about known to the global index.
+  void updateModulesInCommonWithGlobalIndex();
+
 public:
   typedef SmallVector<ModuleFile*, 2>::iterator ModuleIterator;
   typedef SmallVector<ModuleFile*, 2>::const_iterator ModuleConstIterator;
@@ -117,7 +138,10 @@ public:
 
   /// \brief Add an in-memory buffer the list of known buffers
   void addInMemoryBuffer(StringRef FileName, llvm::MemoryBuffer *Buffer);
-  
+
+  /// \brief Set the global module index.
+  void setGlobalIndex(GlobalModuleIndex *Index);
+
   /// \brief Visit each of the modules.
   ///
   /// This routine visits each of the modules, starting with the
@@ -136,7 +160,13 @@ public:
   ///
   /// \param UserData User data associated with the visitor object, which
   /// will be passed along to the visitor.
-  void visit(bool (*Visitor)(ModuleFile &M, void *UserData), void *UserData);
+  ///
+  /// \param ModuleFilesHit If non-NULL, contains the set of module files
+  /// that we know we need to visit because the global module index told us to.
+  /// Any module that is known to both the global module index and the module
+  /// manager that is *not* in this set can be skipped.
+  void visit(bool (*Visitor)(ModuleFile &M, void *UserData), void *UserData,
+             llvm::SmallPtrSet<const FileEntry *, 4> *ModuleFilesHit = 0);
   
   /// \brief Visit each of the modules with a depth-first traversal.
   ///