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

3 files changed, 21 insertions, 31 deletions

diff --git a/lib/Support/Path.cpp b/lib/Support/Path.cpp
index 6d10c0e67b..cfd9ed6db3 100644
--- a/lib/Support/Path.cpp
+++ b/lib/Support/Path.cpp
@@ -638,6 +638,15 @@ bool is_relative(const Twine &path) {
 
 namespace fs {
 
+error_code getUniqueID(const Twine Path, UniqueID &Result) {
+  file_status Status;
+  error_code EC = status(Path, Status);
+  if (EC)
+    return EC;
+  Result = Status.getUniqueID();
+  return error_code::success();
+}
+
 error_code createUniqueFile(const Twine &Model, int &ResultFd,
                             SmallVectorImpl<char> &ResultPath, unsigned Mode) {
   return createUniqueEntity(Model, ResultFd, ResultPath, false, Mode, FS_File);
diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index 5386366b54..0c4518c749 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -293,6 +293,10 @@ TimeValue file_status::getLastModificationTime() const {
   return Ret;
 }
 
+UniqueID file_status::getUniqueID() {
+  return UniqueID(fs_st_dev, fs_st_ino);
+}
+
 error_code current_path(SmallVectorImpl<char> &result) {
 #ifdef MAXPATHLEN
   result.reserve(MAXPATHLEN);
@@ -457,18 +461,6 @@ error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   return error_code::success();
 }
 
-error_code getUniqueID(const Twine Path, uint64_t &Result) {
-  SmallString<128> Storage;
-  StringRef P = Path.toNullTerminatedStringRef(Storage);
-
-  struct stat Status;
-  if (::stat(P.begin(), &Status) != 0)
-    return error_code(errno, system_category());
-
-  Result = Status.st_ino;
-  return error_code::success();
-}
-
 static error_code fillStatus(int StatRet, const struct stat &Status,
                              file_status &Result) {
   if (StatRet != 0) {
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