4 files changed, 35 insertions, 10 deletions
diff --git a/include/clang/Basic/Module.h b/include/clang/Basic/Module.h
index 43edcfacec..422449b6bb 100644
--- a/include/clang/Basic/Module.h
+++ b/include/clang/Basic/Module.h
@@ -78,6 +78,10 @@ public:
   
   ///\ brief The visibility of names within this particular module.
   NameVisibilityKind NameVisibility;
+
+  /// \brief The set of modules imported by this module, and on which this
+  /// module depends.
+  llvm::SmallVector<Module *, 2> Imports;
   
   /// \brief Describes an exported module.
   ///
@@ -89,7 +93,7 @@ public:
   llvm::SmallVector<ExportDecl, 2> Exports;
   
   /// \brief Describes an exported module that has not yet been resolved
-  /// (perhaps because the module it refers to has not yet been loaded).
+  /// (perhaps because tASThe module it refers to has not yet been loaded).
   struct UnresolvedExportDecl {
     /// \brief The location of the 'export' keyword in the module map file.
     SourceLocation ExportLoc;
diff --git a/include/clang/Lex/ModuleMap.h b/include/clang/Lex/ModuleMap.h
index 40488b29fc..fdd5ddbf5f 100644
--- a/include/clang/Lex/ModuleMap.h
+++ b/include/clang/Lex/ModuleMap.h
@@ -167,6 +167,16 @@ public:
   /// false otherwise.
   bool resolveExports(Module *Mod, bool Complain);
 
+  /// \brief Infers the (sub)module based on the given source location and 
+  /// source manager.
+  ///
+  /// \param Loc The location within the source that we are querying, along
+  /// with its source manager.
+  ///
+  /// \returns The module that owns this source location, or null if no
+  /// module owns this source location.
+  Module *inferModuleFromLocation(FullSourceLoc Loc);
+  
   /// \brief Parse the given module map file, and record any modules we 
   /// encounter.
   ///
diff --git a/include/clang/Serialization/ASTBitCodes.h b/include/clang/Serialization/ASTBitCodes.h
index 3d234d9085..17c9992a6c 100644
--- a/include/clang/Serialization/ASTBitCodes.h
+++ b/include/clang/Serialization/ASTBitCodes.h
@@ -517,9 +517,12 @@ namespace clang {
       SUBMODULE_HEADER = 2,
       /// \brief Metadata for submodules as a whole.
       SUBMODULE_METADATA = 3,
+      /// \brief Specifies the submodules that are imported by this 
+      /// submodule.
+      SUBMODULE_IMPORTS = 4,
       /// \brief Specifies the submodules that are re-exported from this 
       /// submodule.
-      SUBMODULE_EXPORTS = 4
+      SUBMODULE_EXPORTS = 5
     };
     
     /// \defgroup ASTAST AST file AST constants
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 552d1a5bff..5e9da51b97 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -393,21 +393,29 @@ private:
   /// declarations in that submodule that could be made visible.
   HiddenNamesMapType HiddenNamesMap;
   
-  /// \brief A module export that hasn't yet been resolved.
-  struct UnresolvedModuleExport {
+  
+  /// \brief A module import or export that hasn't yet been resolved.
+  struct UnresolvedModuleImportExport {
     /// \brief The file in which this module resides.
     ModuleFile *File;
     
-    /// \brief The module that is exporting, along with a bit that specifies
-    /// whether this is a wildcard export.
-    llvm::PointerIntPair<Module *, 1, bool> ModuleAndWildcard;
+    /// \brief The module that is importing or exporting.
+    Module *Mod;
     
     /// \brief The local ID of the module that is being exported.
-    unsigned ExportedID;
+    unsigned ID;
+    
+    /// \brief Whether this is an import (vs. an export).
+    unsigned IsImport : 1;
+    
+    /// \brief Whether this is a wildcard export.
+    unsigned IsWildcard : 1;
   };
   
-  /// \brief The set of module exports that still need to be resolved.
-  llvm::SmallVector<UnresolvedModuleExport, 2> UnresolvedModuleExports;
+  /// \brief The set of module imports and exports that still need to be 
+  /// resolved.
+  llvm::SmallVector<UnresolvedModuleImportExport, 2> 
+    UnresolvedModuleImportExports;
   
   /// \brief A vector containing selectors that have already been loaded.
   ///