5 files changed, 39 insertions, 6 deletions
diff --git a/include/clang/Basic/Module.h b/include/clang/Basic/Module.h
index 4f5280738f..4eaa1be291 100644
--- a/include/clang/Basic/Module.h
+++ b/include/clang/Basic/Module.h
@@ -58,17 +58,33 @@ public:
   /// \brief Whether this is an explicit submodule.
   bool IsExplicit;
   
+  /// \brief Describes the visibility of the various names within a
+  /// particular module.
+  enum NameVisibilityKind {
+    /// \brief All of the names in this module are hidden.
+    ///
+    Hidden,
+    /// \brief Only the macro names in this module are visible.
+    MacrosVisible,
+    /// \brief All of the names in this module are visible.
+    AllVisible
+  };  
+  
+  ///\ brief The visibility of names within this particular module.
+  NameVisibilityKind NameVisibility;
+  
   /// \brief Construct a top-level module.
   explicit Module(StringRef Name, SourceLocation DefinitionLoc,
                   bool IsFramework)
     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(0), UmbrellaHeader(0),
-      IsFramework(IsFramework), IsExplicit(false) { }
+      IsFramework(IsFramework), IsExplicit(false), NameVisibility(Hidden) { }
   
   /// \brief Construct  a new module or submodule.
   Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent, 
          bool IsFramework, bool IsExplicit)
     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent), 
-      UmbrellaHeader(0), IsFramework(IsFramework), IsExplicit(IsExplicit) { }
+      UmbrellaHeader(0), IsFramework(IsFramework), IsExplicit(IsExplicit), 
+      NameVisibility(Hidden) { }
   
   ~Module();
   
diff --git a/include/clang/Frontend/ASTUnit.h b/include/clang/Frontend/ASTUnit.h
index 4cab303ba4..d65da5d67b 100644
--- a/include/clang/Frontend/ASTUnit.h
+++ b/include/clang/Frontend/ASTUnit.h
@@ -781,7 +781,8 @@ public:
   /// \returns True if an error occurred, false otherwise.
   bool serialize(raw_ostream &OS);
   
-  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path) {
+  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path,
+                             Module::NameVisibilityKind Visibility) {
     // ASTUnit doesn't know how to load modules (not that this matters).
     return 0;
   }
diff --git a/include/clang/Frontend/CompilerInstance.h b/include/clang/Frontend/CompilerInstance.h
index 9cd09ee10c..21f8eeead3 100644
--- a/include/clang/Frontend/CompilerInstance.h
+++ b/include/clang/Frontend/CompilerInstance.h
@@ -641,7 +641,8 @@ public:
 
   /// }
   
-  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path);
+  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path,
+                             Module::NameVisibilityKind Visibility);
 };
 
 } // end namespace clang
diff --git a/include/clang/Lex/ModuleLoader.h b/include/clang/Lex/ModuleLoader.h
index 6a7fe0204f..0bd97b6bd4 100644
--- a/include/clang/Lex/ModuleLoader.h
+++ b/include/clang/Lex/ModuleLoader.h
@@ -14,13 +14,13 @@
 #ifndef LLVM_CLANG_LEX_MODULE_LOADER_H
 #define LLVM_CLANG_LEX_MODULE_LOADER_H
 
+#include "clang/Basic/Module.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/ADT/ArrayRef.h"
 
 namespace clang {
 
 class IdentifierInfo;
-class Module;
   
 /// \brief A sequence of identifier/location pairs used to describe a particular
 /// module or submodule, e.g., std.vector.
@@ -41,12 +41,17 @@ public:
   /// parameters.
   ///
   /// \param ImportLoc The location of the 'import' keyword.
+  ///
   /// \param Path The identifiers (and their locations) of the module
   /// "path", e.g., "std.vector" would be split into "std" and "vector".
+  /// 
+  /// \param Visibility The visibility provided for the names in the loaded
+  /// module.
   ///
   /// \returns If successful, returns the loaded module. Otherwise, returns 
   /// NULL to indicate that the module could not be loaded.
-  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path) = 0;
+  virtual Module *loadModule(SourceLocation ImportLoc, ModuleIdPath Path,
+                             Module::NameVisibilityKind Visibility) = 0;
 };
   
 }
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 0e659acfa0..3f66eb5118 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -803,6 +803,16 @@ public:
   /// the actual file in the file system.
   ASTReadResult validateFileEntries(ModuleFile &M);
 
+  /// \brief Make the entities in the given module and any of its (non-explicit)
+  /// submodules visible to name lookup.
+  ///
+  /// \param Mod The module whose names should be made visible.
+  ///
+  /// \param Visibility The level of visibility to give the names in the module.
+  /// Visibility can only be increased over time.
+  void makeModuleVisible(Module *Mod, 
+                         Module::NameVisibilityKind NameVisibility);
+  
   /// \brief Set the AST callbacks listener.
   void setListener(ASTReaderListener *listener) {
     Listener.reset(listener);