diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 5c16782..d97ebb0 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -300,12 +300,16 @@
 
 // File Manager
 
-void CompilerInstance::createFileManager() {
+FileManager *CompilerInstance::createFileManager() {
   if (!hasVirtualFileSystem()) {
-    // TODO: choose the virtual file system based on the CompilerInvocation.
-    setVirtualFileSystem(vfs::getRealFileSystem());
+    if (IntrusiveRefCntPtr<vfs::FileSystem> VFS =
+            createVFSFromCompilerInvocation(getInvocation(), getDiagnostics()))
+      setVirtualFileSystem(VFS);
+    else
+      return nullptr;
   }
   FileMgr = new FileManager(getFileSystemOpts(), VirtualFileSystem);
+  return FileMgr.get();
 }
 
 // Source Manager