Honour -ivfsoverlay in ASTUnit to match clang

This allows code indexing, etc. to use the VFS in the same way as the
compiler.

llvm-svn: 206309

1 files changed, 7 insertions, 24 deletions

diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index dc4dd89371a..dfe3d85ba73 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -211,30 +211,13 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
     return true;
   }
 
-  if (!CI.getHeaderSearchOpts().VFSOverlayFiles.empty()) {
-    IntrusiveRefCntPtr<vfs::OverlayFileSystem>
-        Overlay(new vfs::OverlayFileSystem(vfs::getRealFileSystem()));
-    // earlier vfs files are on the bottom
-    const std::vector<std::string> &Files =
-        CI.getHeaderSearchOpts().VFSOverlayFiles;
-    for (std::vector<std::string>::const_iterator I = Files.begin(),
-                                                  E = Files.end();
-         I != E; ++I) {
-      std::unique_ptr<llvm::MemoryBuffer> Buffer;
-      if (llvm::errc::success != llvm::MemoryBuffer::getFile(*I, Buffer)) {
-        CI.getDiagnostics().Report(diag::err_missing_vfs_overlay_file) << *I;
-        goto failure;
-      }
-
-      IntrusiveRefCntPtr<vfs::FileSystem> FS =
-          vfs::getVFSFromYAML(Buffer.release(), /*DiagHandler*/ 0);
-      if (!FS.getPtr()) {
-        CI.getDiagnostics().Report(diag::err_invalid_vfs_overlay) << *I;
-        goto failure;
-      }
-      Overlay->pushOverlay(FS);
-    }
-    CI.setVirtualFileSystem(Overlay);
+  if (!CI.hasVirtualFileSystem()) {
+    if (IntrusiveRefCntPtr<vfs::FileSystem> VFS =
+          createVFSFromCompilerInvocation(CI.getInvocation(),
+                                          CI.getDiagnostics()))
+      CI.setVirtualFileSystem(VFS);
+    else
+      goto failure;
   }
 
   // Set up the file and source managers, if needed.