Reland [clang] DirectoryWatcher

This reverts commit f561227d133224d2d6a5a016abe4be051fa75501.

- DirectoryWatcher
- Fix the build for platforms that don't have DW implementated.
- Fix the threading dependencies (thanks to compnerd).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@365954 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/DirectoryWatcher/DirectoryScanner.h b/lib/DirectoryWatcher/DirectoryScanner.h
new file mode 100644
index 0000000000..55731225e2
--- /dev/null
+++ b/lib/DirectoryWatcher/DirectoryScanner.h
@@ -0,0 +1,29 @@
+//===- DirectoryScanner.h - Utility functions for DirectoryWatcher --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/DirectoryWatcher/DirectoryWatcher.h"
+#include "llvm/Support/FileSystem.h"
+#include <string>
+#include <vector>
+
+namespace clang {
+
+/// Gets names (filenames) of items in directory at \p Path.
+/// \returns empty vector if \p Path is not a directory, doesn't exist or can't
+/// be read from.
+std::vector<std::string> scanDirectory(llvm::StringRef Path);
+
+/// Create event with EventKind::Added for every element in \p Scan.
+std::vector<DirectoryWatcher::Event>
+getAsFileEvents(const std::vector<std::string> &Scan);
+
+/// Gets status of file (or directory) at \p Path.
+/// \returns llvm::None if \p Path doesn't exist or can't get the status.
+llvm::Optional<llvm::sys::fs::file_status> getFileStatus(llvm::StringRef Path);
+
+} // namespace clang
\ No newline at end of file