Use llvm::sys::fs::UniqueID for windows and unix.

This unifies the unix and windows versions of FileManager::UniqueDirContainer
and FileManager::UniqueFileContainer by using UniqueID.

We cannot just replace "struct stat" with llvm::sys::fs::file_status, since we
want to be able to construct fake ones, and file_status has different members
on unix and windows.

What the patch does is:

* Record only the information that clang is actually using.
* Use llvm::sys::fs::status instead of stat and fstat.
* Use llvm::sys::fs::UniqueID
* Delete the old windows versions of UniqueDirContainer and
UniqueFileContainer since the "unix" one now works on windows too.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/FileSystemStatCache.cpp b/lib/Basic/FileSystemStatCache.cpp
index b71259e..7a01bff 100644
--- a/lib/Basic/FileSystemStatCache.cpp
+++ b/lib/Basic/FileSystemStatCache.cpp
@@ -30,6 +30,16 @@
 
 void FileSystemStatCache::anchor() { }
 
+static void copyStatusToFileData(const llvm::sys::fs::file_status &Status,
+                                 FileData &Data) {
+  Data.Size = Status.getSize();
+  Data.ModTime = Status.getLastModificationTime().toEpochTime();
+  Data.UniqueID = Status.getUniqueID();
+  Data.IsDirectory = is_directory(Status);
+  Data.IsNamedPipe = Status.type() == llvm::sys::fs::file_type::fifo_file;
+  Data.InPCH = false;
+}
+
 /// FileSystemStatCache::get - Get the 'stat' information for the specified
 /// path, using the cache to accelerate it if possible.  This returns true if
 /// the path does not exist or false if it exists.
@@ -39,19 +49,24 @@
 /// success for directories (not files).  On a successful file lookup, the
 /// implementation can optionally fill in FileDescriptor with a valid
 /// descriptor and the client guarantees that it will close it.
-bool FileSystemStatCache::get(const char *Path, struct stat &StatBuf,
-                              bool isFile, int *FileDescriptor,
-                              FileSystemStatCache *Cache) {
+bool FileSystemStatCache::get(const char *Path, FileData &Data, bool isFile,
+                              int *FileDescriptor, FileSystemStatCache *Cache) {
   LookupResult R;
   bool isForDir = !isFile;
 
   // If we have a cache, use it to resolve the stat query.
   if (Cache)
-    R = Cache->getStat(Path, StatBuf, isFile, FileDescriptor);
+    R = Cache->getStat(Path, Data, isFile, FileDescriptor);
   else if (isForDir || !FileDescriptor) {
     // If this is a directory or a file descriptor is not needed and we have
     // no cache, just go to the file system.
-    R = ::stat(Path, &StatBuf) != 0 ? CacheMissing : CacheExists;
+    llvm::sys::fs::file_status Status;
+    if (llvm::sys::fs::status(Path, Status)) {
+      R = CacheMissing;
+    } else {
+      R = CacheExists;
+      copyStatusToFileData(Status, Data);
+    }
   } else {
     // Otherwise, we have to go to the filesystem.  We can always just use
     // 'stat' here, but (for files) the client is asking whether the file exists
@@ -69,9 +84,11 @@
       // Otherwise, the open succeeded.  Do an fstat to get the information
       // about the file.  We'll end up returning the open file descriptor to the
       // client to do what they please with it.
-      if (::fstat(*FileDescriptor, &StatBuf) == 0)
+      llvm::sys::fs::file_status Status;
+      if (!llvm::sys::fs::status(*FileDescriptor, Status)) {
         R = CacheExists;
-      else {
+        copyStatusToFileData(Status, Data);
+      } else {
         // fstat rarely fails.  If it does, claim the initial open didn't
         // succeed.
         R = CacheMissing;
@@ -86,7 +103,7 @@
   
   // If the path exists, make sure that its "directoryness" matches the clients
   // demands.
-  if (S_ISDIR(StatBuf.st_mode) != isForDir) {
+  if (Data.IsDirectory != isForDir) {
     // If not, close the file if opened.
     if (FileDescriptor && *FileDescriptor != -1) {
       ::close(*FileDescriptor);
@@ -99,12 +116,11 @@
   return false;
 }
 
-
 MemorizeStatCalls::LookupResult
-MemorizeStatCalls::getStat(const char *Path, struct stat &StatBuf,
-                           bool isFile, int *FileDescriptor) {
-  LookupResult Result = statChained(Path, StatBuf, isFile, FileDescriptor);
-  
+MemorizeStatCalls::getStat(const char *Path, FileData &Data, bool isFile,
+                           int *FileDescriptor) {
+  LookupResult Result = statChained(Path, Data, isFile, FileDescriptor);
+
   // Do not cache failed stats, it is easy to construct common inconsistent
   // situations if we do, and they are not important for PCH performance (which
   // currently only needs the stats to construct the initial FileManager
@@ -113,8 +129,8 @@
     return Result;
   
   // Cache file 'stat' results and directories with absolutely paths.
-  if (!S_ISDIR(StatBuf.st_mode) || llvm::sys::path::is_absolute(Path))
-    StatCalls[Path] = StatBuf;
-  
+  if (!Data.IsDirectory || llvm::sys::path::is_absolute(Path))
+    StatCalls[Path] = Data;
+
   return Result;
 }