1 files changed, 42 insertions, 0 deletions
diff --git a/clangd/FSProvider.h b/clangd/FSProvider.h
new file mode 100644
index 00000000..70dfb441
--- /dev/null
+++ b/clangd/FSProvider.h
@@ -0,0 +1,42 @@
+//===--- FSProvider.h - VFS provider for ClangdServer ------------*- C++-*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_FSPROVIDER_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_FSPROVIDER_H
+
+#include "clang/Basic/VirtualFileSystem.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+
+namespace clang {
+namespace clangd {
+
+// Wrapper for vfs::FileSystem for use in multithreaded programs like clangd.
+// As FileSystem is not threadsafe, concurrent threads must each obtain one.
+class FileSystemProvider {
+public:
+  virtual ~FileSystemProvider() = default;
+  /// Called by ClangdServer to obtain a vfs::FileSystem to be used for parsing.
+  /// Context::current() will be the context passed to the clang entrypoint,
+  /// such as addDocument(), and will also be propagated to result callbacks.
+  /// Embedders may use this to isolate filesystem accesses.
+  virtual IntrusiveRefCntPtr<vfs::FileSystem> getFileSystem() = 0;
+};
+
+class RealFileSystemProvider : public FileSystemProvider {
+public:
+  // FIXME: returns the single real FS instance, which is not threadsafe.
+  IntrusiveRefCntPtr<vfs::FileSystem> getFileSystem() override {
+    return vfs::getRealFileSystem();
+  }
+};
+
+} // namespace clangd
+} // namespace clang
+
+#endif