1 files changed, 21 insertions, 0 deletions
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 00dbfabb45..15db7050e9 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -3335,6 +3335,27 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
        I != E; ++I)
     WriteDeclContextVisibleUpdate(*I);
 
+  // Write the submodules that were imported, if any.
+  RecordData ImportedModules;
+  for (ASTContext::import_iterator I = Context.local_import_begin(),
+                                IEnd = Context.local_import_end();
+       I != IEnd; ++I) {
+    assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
+    ImportedModules.push_back(SubmoduleIDs[I->getImportedModule()]);
+  }
+  if (!ImportedModules.empty()) {
+    // Sort module IDs.
+    llvm::array_pod_sort(ImportedModules.begin(), ImportedModules.end());
+    
+    // Unique module IDs.
+    ImportedModules.erase(std::unique(ImportedModules.begin(), 
+                                      ImportedModules.end()),
+                          ImportedModules.end());
+    
+    Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
+    ImportedModules.clear();
+  }
+  
   WriteDeclUpdatesBlocks();
   WriteDeclReplacementsBlock();
   WriteChainedObjCCategories();