5 files changed, 16 insertions, 3 deletions
diff --git a/lib/Basic/LangOptions.cpp b/lib/Basic/LangOptions.cpp
index 5f479dbb77..991992a477 100644
--- a/lib/Basic/LangOptions.cpp
+++ b/lib/Basic/LangOptions.cpp
@@ -26,5 +26,7 @@ void LangOptions::resetNonModularOptions() {
 #define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
   Name = Default;
 #include "clang/Basic/LangOptions.def"
+  
+  CurrentModule.clear();
 }
 
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 0e3b25168f..ea2c3bd6c6 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -278,9 +278,7 @@ void CompilerInstance::createPreprocessor() {
     llvm::sys::path::append(SpecificModuleCache,
                             getInvocation().getModuleHash());
   PP->getHeaderSearchInfo().configureModules(SpecificModuleCache,
-    getPreprocessorOpts().ModuleBuildPath.empty()
-      ? std::string()
-      : getPreprocessorOpts().ModuleBuildPath.back());
+                                             getLangOpts().CurrentModule);
 
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
@@ -992,6 +990,9 @@ static void compileModule(CompilerInstance &ImportingInstance,
   Invocation->getLangOpts().resetNonModularOptions();
   Invocation->getPreprocessorOpts().resetNonModularOptions();
 
+  // Note the name of the module we're building.
+  Invocation->getLangOpts().CurrentModule = ModuleName;
+
   // Note that this module is part of the module build path, so that we
   // can detect cycles in the module graph.
   Invocation->getPreprocessorOpts().ModuleBuildPath.push_back(ModuleName);
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index c247e21737..015288c853 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -788,6 +788,8 @@ static void LangOptsToArgs(const LangOptions &Opts,
     Res.push_back("-fdeprecated-macro");
   if (Opts.ApplePragmaPack)
     Res.push_back("-fapple-pragma-pack");
+  if (!Opts.CurrentModule.empty())
+    Res.push_back("-fmodule-name=" + Opts.CurrentModule);
 }
 
 static void PreprocessorOptsToArgs(const PreprocessorOptions &Opts,
@@ -1785,6 +1787,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.ParseUnknownAnytype = Args.hasArg(OPT_funknown_anytype);
   Opts.DebuggerSupport = Args.hasArg(OPT_fdebugger_support);
   Opts.ApplePragmaPack = Args.hasArg(OPT_fapple_pragma_pack);
+  Opts.CurrentModule = Args.getLastArgValue(OPT_fmodule_name);
 
   // Record whether the __DEPRECATED define was requested.
   Opts.Deprecated = Args.hasFlag(OPT_fdeprecated_macro,
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 6192fb7751..8961974856 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2789,6 +2789,10 @@ bool ASTReader::ParseLanguageOptions(
   LangOpts.set##Name(static_cast<LangOptions::Type>(Record[Idx++]));
 #include "clang/Basic/LangOptions.def"
     
+    unsigned Length = Record[Idx++];
+    LangOpts.CurrentModule.assign(Record.begin() + Idx, 
+                                  Record.begin() + Idx + Length);
+    Idx += Length;
     return Listener->ReadLanguageOptions(LangOpts);
   }
 
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 4fa3cf8756..6893dbd9f5 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1063,6 +1063,9 @@ void ASTWriter::WriteLanguageOptions(const LangOptions &LangOpts) {
 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
 #include "clang/Basic/LangOptions.def"  
+  
+  Record.push_back(LangOpts.CurrentModule.size());
+  Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
 }