3 files changed, 36 insertions, 2 deletions
diff --git a/include/clang/Lex/HeaderSearch.h b/include/clang/Lex/HeaderSearch.h
index b56fba538a..a6d7520f29 100644
--- a/include/clang/Lex/HeaderSearch.h
+++ b/include/clang/Lex/HeaderSearch.h
@@ -207,6 +207,15 @@ public:
     //LookupFileCache.clear();
   }
 
+  /// AddSearchPath - Add an additional search path.
+  void AddSearchPath(const DirectoryLookup &dir, bool isAngled) {
+    unsigned idx = isAngled ? SystemDirIdx : AngledDirIdx;
+    SearchDirs.insert(SearchDirs.begin() + idx, dir);
+    if (!isAngled)
+      AngledDirIdx++;
+    SystemDirIdx++;
+  }
+
   /// \brief Set the path to the module cache and the name of the module
   /// we're building
   void configureModules(StringRef CachePath, StringRef BuildingModule) {
@@ -266,7 +275,8 @@ public:
                               const FileEntry *CurFileEnt,
                               SmallVectorImpl<char> *SearchPath,
                               SmallVectorImpl<char> *RelativePath,
-                              ModuleMap::Module **SuggestedModule);
+                              ModuleMap::Module **SuggestedModule,
+                              bool SkipCache = false);
 
   /// LookupSubframeworkHeader - Look up a subframework for the specified
   /// #include file.  For example, if #include'ing <HIToolbox/HIToolbox.h> from
diff --git a/include/clang/Lex/PPCallbacks.h b/include/clang/Lex/PPCallbacks.h
index 1fc1a05db6..0c783d474d 100644
--- a/include/clang/Lex/PPCallbacks.h
+++ b/include/clang/Lex/PPCallbacks.h
@@ -58,6 +58,23 @@ public:
                            SrcMgr::CharacteristicKind FileType) {
   }
 
+  /// FileNotFound - This callback is invoked whenever an inclusion directive
+  /// results in a file-not-found error.
+  ///
+  /// \param FileName The name of the file being included, as written in the 
+  /// source code.
+  ///
+  /// \param RecoveryPath If this client indicates that it can recover from 
+  /// this missing file, the client should set this as an additional header
+  /// search patch.
+  ///
+  /// \returns true to indicate that the preprocessor should attempt to recover
+  /// by adding \p RecoveryPath as a header search path.
+  virtual bool FileNotFound(StringRef FileName,
+                            SmallVectorImpl<char> &RecoveryPath) {
+    return false;
+  }
+
   /// \brief This callback is invoked whenever an inclusion directive of
   /// any kind (\c #include, \c #import, etc.) has been processed, regardless
   /// of whether the inclusion will actually result in an inclusion.
@@ -231,6 +248,12 @@ public:
     Second->FileSkipped(ParentFile, FilenameTok, FileType);
   }
 
+  virtual bool FileNotFound(StringRef FileName,
+                            SmallVectorImpl<char> &RecoveryPath) {
+    return First->FileNotFound(FileName, RecoveryPath) ||
+           Second->FileNotFound(FileName, RecoveryPath);
+  }
+
   virtual void InclusionDirective(SourceLocation HashLoc,
                                   const Token &IncludeTok,
                                   StringRef FileName,
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 90f64c4554..cf77824120 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -1008,7 +1008,8 @@ public:
                               const DirectoryLookup *&CurDir,
                               SmallVectorImpl<char> *SearchPath,
                               SmallVectorImpl<char> *RelativePath,
-                              ModuleMap::Module **SuggestedModule);
+                              ModuleMap::Module **SuggestedModule,
+                              bool SkipCache = false);
 
   /// GetCurLookup - The DirectoryLookup structure used to find the current
   /// FileEntry, if CurLexer is non-null and if applicable.  This allows us to