6 files changed, 35 insertions, 9 deletions
diff --git a/include/clang/Basic/FileManager.h b/include/clang/Basic/FileManager.h
index 826859fb50..ea8ed9f02f 100644
--- a/include/clang/Basic/FileManager.h
+++ b/include/clang/Basic/FileManager.h
@@ -179,18 +179,21 @@ public:
   /// getDirectory - Lookup, cache, and verify the specified directory
   /// (real or virtual).  This returns NULL if the directory doesn't exist.
   ///
-  const DirectoryEntry *getDirectory(StringRef DirName);
+  /// \param CacheFailure If true and the file does not exist, we'll cache
+  /// the failure to find this file.
+  const DirectoryEntry *getDirectory(StringRef DirName,
+                                     bool CacheFailure = true);
 
   /// \brief Lookup, cache, and verify the specified file (real or
   /// virtual).  This returns NULL if the file doesn't exist.
   ///
-  /// \param openFile if true and the file exists, it will be opened.
-  const FileEntry *getFile(StringRef Filename, bool openFile = false);
+  /// \param OpenFile if true and the file exists, it will be opened.
+  ///
+  /// \param CacheFailure If true and the file does not exist, we'll cache
+  /// the failure to find this file.
+  const FileEntry *getFile(StringRef Filename, bool OpenFile = false,
+                           bool CacheFailure = true);
 
-  /// \brief Forget any information about the given file name, because (for 
-  /// example) something within this process has changed the file in some way.
-  void forgetFile(StringRef Filename);
-  
   /// \brief Returns the current file system options
   const FileSystemOptions &getFileSystemOptions() { return FileSystemOpts; }
 
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index e3d79ac385..9969abb600 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -608,7 +608,9 @@ def nobuiltininc : Flag<"-nobuiltininc">,
 def fmodule_cache_path : JoinedOrSeparate<"-fmodule-cache-path">, 
   MetaVarName<"<directory>">,
   HelpText<"Specify the module cache path">;           
-
+def fdisable_module_hash : Flag<"-fdisable-module-hash">,
+  HelpText<"Disable the module hash">;
+  
 def F : JoinedOrSeparate<"-F">, MetaVarName<"<directory>">,
   HelpText<"Add directory to framework include search path">;
 def I : JoinedOrSeparate<"-I">, MetaVarName<"<directory>">,
diff --git a/include/clang/Frontend/CompilerInvocation.h b/include/clang/Frontend/CompilerInvocation.h
index 23ddc84304..f09c97ec3f 100644
--- a/include/clang/Frontend/CompilerInvocation.h
+++ b/include/clang/Frontend/CompilerInvocation.h
@@ -123,6 +123,10 @@ public:
   static void setLangDefaults(LangOptions &Opts, InputKind IK,
                    LangStandard::Kind LangStd = LangStandard::lang_unspecified);
   
+  /// \brief Retrieve a module hash string that is suitable for uniquely 
+  /// identifying the conditions under which the module was built.
+  std::string getModuleHash() const;
+  
   /// @}
   /// @name Option Subgroups
   /// @{
diff --git a/include/clang/Frontend/HeaderSearchOptions.h b/include/clang/Frontend/HeaderSearchOptions.h
index a81a0cb992..e0f80e3bdf 100644
--- a/include/clang/Frontend/HeaderSearchOptions.h
+++ b/include/clang/Frontend/HeaderSearchOptions.h
@@ -78,6 +78,12 @@ public:
   /// \brief The directory used for the module cache.
   std::string ModuleCachePath;
   
+  /// \brief Whether we should disable the use of the hash string within the
+  /// module cache.
+  ///
+  /// Note: Only used for testing!
+  unsigned DisableModuleHash : 1;
+  
   /// Include the compiler builtin includes.
   unsigned UseBuiltinIncludes : 1;
 
@@ -95,7 +101,7 @@ public:
 
 public:
   HeaderSearchOptions(StringRef _Sysroot = "/")
-    : Sysroot(_Sysroot), UseBuiltinIncludes(true),
+    : Sysroot(_Sysroot), DisableModuleHash(0), UseBuiltinIncludes(true),
       UseStandardIncludes(true), UseStandardCXXIncludes(true), UseLibcxx(false),
       Verbose(false) {}
 
diff --git a/include/clang/Frontend/PreprocessorOptions.h b/include/clang/Frontend/PreprocessorOptions.h
index 3df6512600..4065ae6ff6 100644
--- a/include/clang/Frontend/PreprocessorOptions.h
+++ b/include/clang/Frontend/PreprocessorOptions.h
@@ -195,10 +195,17 @@ public:
   /// module.
   void resetNonModularOptions() {
     Macros.clear();
+    Includes.clear();
+    Modules.clear();
     MacroIncludes.clear();
+    ChainedIncludes.clear();
     DumpDeserializedPCHDecls = false;
+    ImplicitPCHInclude.clear();
+    ImplicitPTHInclude.clear();
     TokenCache.clear();
     RetainRemappedFileBuffers = true;
+    PrecompiledPreambleBytes.first = 0;
+    PrecompiledPreambleBytes.second = 0;
   }
 };
 
diff --git a/include/clang/Lex/HeaderSearch.h b/include/clang/Lex/HeaderSearch.h
index 74c1080df8..86aa7c974a 100644
--- a/include/clang/Lex/HeaderSearch.h
+++ b/include/clang/Lex/HeaderSearch.h
@@ -319,6 +319,9 @@ public:
   /// \brief Search in the module cache path for a module with the given
   /// name.
   ///
+  /// \param If non-NULL, will be set to the module file name we expected to
+  /// find (regardless of whether it was actually found or not).
+  ///
   /// \param UmbrellaHeader If non-NULL, and no module was found in the module
   /// cache, this routine will search in the framework paths to determine
   /// whether a module can be built from an umbrella header. If so, the pointee
@@ -327,6 +330,7 @@ public:
   /// \returns A file describing the named module, if available, or NULL to
   /// indicate that the module could not be found.
   const FileEntry *lookupModule(StringRef ModuleName,
+                                std::string *ModuleFileName = 0,
                                 std::string *UmbrellaHeader = 0);
   
   void IncrementFrameworkLookupCount() { ++NumFrameworkLookups; }