5 files changed, 15 insertions, 6 deletions
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 7f6ae5680e7..d617b368065 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -20,6 +20,7 @@
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
+#include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendActions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
@@ -37,7 +38,6 @@
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/Atomic.h"
 #include "llvm/Support/CrashRecoveryContext.h"
-#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Mutex.h"
@@ -1421,7 +1421,7 @@ llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
              REnd = PreprocessorOpts.remapped_file_end();
            !AnyFileChanged && R != REnd;
            ++R) {
-        llvm::sys::fs::file_status Status;
+        vfs::Status Status;
         if (FileMgr->getNoncachedStatValue(R->second, Status)) {
           // If we can't stat the file we're remapping to, assume that something
           // horrible happened.
@@ -1457,7 +1457,7 @@ llvm::MemoryBuffer *ASTUnit::getMainBufferWithPrecompiledPreamble(
         }
         
         // The file was not remapped; check whether it has changed on disk.
-        llvm::sys::fs::file_status Status;
+        vfs::Status Status;
         if (FileMgr->getNoncachedStatValue(F->first(), Status)) {
           // If we can't stat the file, assume that something horrible happened.
           AnyFileChanged = true;
diff --git a/clang/lib/Frontend/CacheTokens.cpp b/clang/lib/Frontend/CacheTokens.cpp
index 0c30b049579..5cb364e3f5c 100644
--- a/clang/lib/Frontend/CacheTokens.cpp
+++ b/clang/lib/Frontend/CacheTokens.cpp
@@ -516,8 +516,8 @@ public:
   ~StatListener() {}
 
   LookupResult getStat(const char *Path, FileData &Data, bool isFile,
-                       int *FileDescriptor) {
-    LookupResult Result = statChained(Path, Data, isFile, FileDescriptor);
+                       vfs::File **F, vfs::FileSystem &FS) {
+    LookupResult Result = statChained(Path, Data, isFile, F, FS);
 
     if (Result == CacheMissing) // Failed 'stat'.
       PM.insert(PTHEntryKeyVariant(Path), PTHEntry());
diff --git a/clang/lib/Frontend/ChainedIncludesSource.cpp b/clang/lib/Frontend/ChainedIncludesSource.cpp
index 442177ec319..d6d63bfb005 100644
--- a/clang/lib/Frontend/ChainedIncludesSource.cpp
+++ b/clang/lib/Frontend/ChainedIncludesSource.cpp
@@ -101,6 +101,7 @@ ChainedIncludesSource *ChainedIncludesSource::create(CompilerInstance &CI) {
     Clang->setDiagnostics(Diags.getPtr());
     Clang->setTarget(TargetInfo::CreateTargetInfo(Clang->getDiagnostics(),
                                                   &Clang->getTargetOpts()));
+    Clang->createVirtualFileSystem();
     Clang->createFileManager();
     Clang->createSourceManager(Clang->getFileManager());
     Clang->createPreprocessor();
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 61fe26c9222..0e9b0c0ebe3 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -194,9 +194,14 @@ CompilerInstance::createDiagnostics(DiagnosticOptions *Opts,
   return Diags;
 }
 
+void CompilerInstance::createVirtualFileSystem() {
+  VirtualFileSystem = vfs::getRealFileSystem();
+}
+
 // File Manager
 
 void CompilerInstance::createFileManager() {
+  assert(hasVirtualFileSystem() && "expected virtual file system");
   FileMgr = new FileManager(getFileSystemOpts());
 }
 
@@ -867,6 +872,8 @@ static void compileModule(CompilerInstance &ImportingInstance,
                                    ImportingInstance.getDiagnosticClient()),
                              /*ShouldOwnClient=*/true);
 
+  Instance.setVirtualFileSystem(&ImportingInstance.getVirtualFileSystem());
+
   // Note that this module is part of the module build stack, so that we
   // can detect cycles in the module graph.
   Instance.createFileManager(); // FIXME: Adopt file manager from importer?
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 0baf3e5e1fb..4e04c2c0e83 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -159,7 +159,6 @@ ASTConsumer* FrontendAction::CreateWrappedASTConsumer(CompilerInstance &CI,
   return new MultiplexConsumer(Consumers);
 }
 
-
 bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
                                      const FrontendInputFile &Input) {
   assert(!Instance && "Already processing a source file!");
@@ -213,6 +212,8 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
   }
 
   // Set up the file and source managers, if needed.
+  if (!CI.hasVirtualFileSystem())
+    CI.createVirtualFileSystem();
   if (!CI.hasFileManager())
     CI.createFileManager();
   if (!CI.hasSourceManager())