1 files changed, 8 insertions, 2 deletions
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 66bec7c4ae..633b82c2e0 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -40,8 +40,7 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
 
   // AST files follow a very different path, since they share objects via the
   // AST unit.
-  bool IsAST = InputKind == IK_AST;
-  if (IsAST) {
+  if (InputKind == IK_AST) {
     assert(!usesPreprocessorOnly() &&
            "Attempt to pass AST file to preprocessor only action!");
     assert(hasASTSupport() && "This action does not have AST support!");
@@ -73,6 +72,13 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
     return true;
   }
 
+  // Setup the file and source managers, if needed, and the preprocessor.
+  if (!CI.hasFileManager())
+    CI.createFileManager();
+  if (!CI.hasSourceManager())
+    CI.createSourceManager();
+  CI.createPreprocessor();
+
   // Inform the diagnostic client we are processing a source file.
   CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(),
                                            &CI.getPreprocessor());