Include st_dev to make the result of getUniqueID actually unique.

This will let us use getUniqueID instead of st_dev directly on clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187378 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 19 deletions

diff --git a/lib/Support/Windows/Path.inc b/lib/Support/Windows/Path.inc
index 9936343167..f3460e4c19 100644
--- a/lib/Support/Windows/Path.inc
+++ b/lib/Support/Windows/Path.inc
@@ -269,6 +269,14 @@ std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
   return ret != MAX_PATH ? pathname : "";
 }
 
+UniqueID file_status::getUniqueID() {
+  // The file is uniquely identified by the volume serial number along
+  // with the 64-bit file identifier.
+  uint64_t FileID = (static_cast<uint64_t>(FileIndexHigh) << 32ULL) |
+                    static_cast<uint64_t>(FileIndexLow);
+
+  return UniqueID(VolumeSerialNumber, FileID);
+}
 
 TimeValue file_status::getLastModificationTime() const {
   ULARGE_INTEGER UI;
@@ -533,25 +541,6 @@ error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   return error_code::success();
 }
 
-error_code getUniqueID(const Twine Path, uint64_t &Result) {
-  file_status Status;
-  if (error_code E = status(Path, Status))
-    return E;
-
-  // The file is uniquely identified by the volume serial number along
-  // with the 64-bit file identifier.
-  Result = (static_cast<uint64_t>(Status.FileIndexHigh) << 32ULL) |
-           static_cast<uint64_t>(Status.FileIndexLow);
-  
-  // Because the serial number is 32-bits, but we've already used up all 64
-  // bits for the file index, XOR the serial number into the high 32 bits of
-  // the resulting value.  We could potentially get collisons from this, but
-  // the likelihood is low.
-  Result ^= (static_cast<uint64_t>(Status.VolumeSerialNumber) << 32ULL);
-
-  return error_code::success();
-}
-
 static bool isReservedName(StringRef path) {
   // This list of reserved names comes from MSDN, at:
   // http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx