Bazel client, Windows: impl. ForEachDirectoryEntry

Implement ForEachDirectoryEntry on Windows using
FindFirstFileW / FindNextFileW.

Supports long paths and traversing junctions.

See https://github.com/bazelbuild/bazel/issues/2107
See https://github.com/bazelbuild/bazel/issues/2181

--
PiperOrigin-RevId: 145062749
MOS_MIGRATED_REVID=145062749

2 files changed, 29 insertions, 6 deletions

diff --git a/src/main/cpp/util/file_posix.cc b/src/main/cpp/util/file_posix.cc
index a1d806a9d9..c45eb3915c 100644
--- a/src/main/cpp/util/file_posix.cc
+++ b/src/main/cpp/util/file_posix.cc
@@ -364,7 +364,6 @@ string GetCwd() {
 bool ChangeDirectory(const string& path) {
   return chdir(path.c_str()) == 0;
 }
-#endif  // not __CYGWIN__
 
 void ForEachDirectoryEntry(const string &path,
                            DirectoryEntryConsumer *consume) {
@@ -398,5 +397,6 @@ void ForEachDirectoryEntry(const string &path,
 
   closedir(dir);
 }
+#endif  // not __CYGWIN__
 
 }  // namespace blaze_util
diff --git a/src/main/cpp/util/file_windows.cc b/src/main/cpp/util/file_windows.cc
index b1fadddf4a..bea092d9ff 100644
--- a/src/main/cpp/util/file_windows.cc
+++ b/src/main/cpp/util/file_windows.cc
@@ -993,14 +993,37 @@ bool ChangeDirectory(const string& path) {
   return true;
 }
 
-#ifdef COMPILER_MSVC
 void ForEachDirectoryEntry(const string &path,
                            DirectoryEntryConsumer *consume) {
-  // TODO(bazel-team): implement this.
-  pdie(255, "blaze_util::ForEachDirectoryEntry is not implemented on Windows");
+  wstring wpath;
+  if (path.empty() || IsDevNull(path)) {
+    return;
+  }
+  if (!AsWindowsPath(path, &wpath)) {
+    pdie(blaze_exit_code::LOCAL_ENVIRONMENTAL_ERROR,
+         "ForEachDirectoryEntry(%s): AsWindowsPath failed", path.c_str());
+  }
+
+  static const wstring kDot(L".");
+  static const wstring kDotDot(L"..");
+
+  wpath = L"\\\\?\\" + wpath + L"\\";
+  WIN32_FIND_DATAW metadata;
+  windows_util::AutoHandle handle(
+      FindFirstFileW((wpath + L"*").c_str(), &metadata));
+  if (handle.handle == INVALID_HANDLE_VALUE) {
+    return;  // directory does not exist or is empty
+  }
+
+  do {
+    if (kDot != metadata.cFileName && kDotDot != metadata.cFileName) {
+      wstring wname = wpath + metadata.cFileName;
+      string name(WstringToCstring(/* omit prefix */ 4 + wname.c_str()).get());
+      bool is_dir = (metadata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
+      consume->Consume(name, is_dir);
+    }
+  } while (FindNextFileW(handle.handle, &metadata));
 }
-#else   // not COMPILER_MSVC
-#endif  // COMPILER_MSVC
 
 string NormalizeWindowsPath(string path) {
   if (path.empty()) {