Add lastAccessedTime to file_status

[mehdi_amini]

Note: I didn't test the windows part, I wrote it by reading https://msdn.microsoft.com/en-us/library/windows/desktop/ms724320(v=vs.85).aspx

[• rafael]

So, the code looks fine, but given how limited the OS support is, is this
useful?

What cache replacement policy is used by clang? Or by ccache?

Cheers,
Rafael

[mehdi_amini]

(Mark as accepted per Rafael on the mailing list)

[mehdi_amini]

r264392

include/llvm/Support/FileSystem.h

 
 /// file_status - Represents the result of a call to stat and friends. It has
 ///               a platform-specific member to store the result.
 class file_status
 {
   #if defined(LLVM_ON_UNIX)
   dev_t fs_st_dev;
   ino_t fs_st_ino;
+  time_t fs_st_atime;
   time_t fs_st_mtime;
   uid_t fs_st_uid;
   gid_t fs_st_gid;
   off_t fs_st_size;
   #elif defined (LLVM_ON_WIN32)
+  uint32_t LastAccessedTimeHigh;
+  uint32_t LastAccessedTimeLow;
   uint32_t LastWriteTimeHigh;
   uint32_t LastWriteTimeLow;
   uint32_t VolumeSerialNumber;
   uint32_t FileSizeHigh;
   uint32_t FileSizeLow;
   uint32_t FileIndexHigh;
   uint32_t FileIndexLow;
   #endif
   friend bool equivalent(file_status A, file_status B);
   file_type Type;
   perms Perms;
 
 public:
   #if defined(LLVM_ON_UNIX)
-    file_status() : fs_st_dev(0), fs_st_ino(0), fs_st_mtime(0),
+  file_status()
+      : fs_st_dev(0), fs_st_ino(0), fs_st_atime(0), fs_st_mtime(0),
         fs_st_uid(0), fs_st_gid(0), fs_st_size(0),
         Type(file_type::status_error), Perms(perms_not_known) {}
 
-    file_status(file_type Type) : fs_st_dev(0), fs_st_ino(0), fs_st_mtime(0),
+  file_status(file_type Type)
+      : fs_st_dev(0), fs_st_ino(0), fs_st_atime(0), fs_st_mtime(0),
         fs_st_uid(0), fs_st_gid(0), fs_st_size(0), Type(Type),
         Perms(perms_not_known) {}
 
-    file_status(file_type Type, perms Perms, dev_t Dev, ino_t Ino, time_t MTime,
-                uid_t UID, gid_t GID, off_t Size)
-        : fs_st_dev(Dev), fs_st_ino(Ino), fs_st_mtime(MTime), fs_st_uid(UID),
-          fs_st_gid(GID), fs_st_size(Size), Type(Type), Perms(Perms) {}
+              time_t ATime, uid_t UID, gid_t GID, off_t Size)
+      : fs_st_dev(Dev), fs_st_ino(Ino), fs_st_atime(ATime), fs_st_mtime(MTime),
+        fs_st_uid(UID), fs_st_gid(GID), fs_st_size(Size), Type(Type),
+        Perms(Perms) {}
   #elif defined(LLVM_ON_WIN32)
-    file_status() : LastWriteTimeHigh(0), LastWriteTimeLow(0),
-        VolumeSerialNumber(0), FileSizeHigh(0), FileSizeLow(0),
-        FileIndexHigh(0), FileIndexLow(0), Type(file_type::status_error),
-        Perms(perms_not_known) {}
+  file_status()
+      : LastAccessedTimeHigh(0), LastAccessedTimeLow(0), LastWriteTimeHigh(0),
+        LastWriteTimeLow(0), VolumeSerialNumber(0), FileSizeHigh(0),
+        FileSizeLow(0), FileIndexHigh(0), FileIndexLow(0),
+        Type(file_type::status_error), Perms(perms_not_known) {}
 
-    file_status(file_type Type) : LastWriteTimeHigh(0), LastWriteTimeLow(0),
-        VolumeSerialNumber(0), FileSizeHigh(0), FileSizeLow(0),
-        FileIndexHigh(0), FileIndexLow(0), Type(Type),
+  file_status(file_type Type)
+      : LastAccessedTimeHigh(0), LastAccessedTimeLow(0), LastWriteTimeHigh(0),
+        LastWriteTimeLow(0), VolumeSerialNumber(0), FileSizeHigh(0),
+        FileSizeLow(0), FileIndexHigh(0), FileIndexLow(0), Type(Type),
         Perms(perms_not_known) {}
 
-    file_status(file_type Type, uint32_t LastWriteTimeHigh,
-                uint32_t LastWriteTimeLow, uint32_t VolumeSerialNumber,
-                uint32_t FileSizeHigh, uint32_t FileSizeLow,
-                uint32_t FileIndexHigh, uint32_t FileIndexLow)
-        : LastWriteTimeHigh(LastWriteTimeHigh),
-          LastWriteTimeLow(LastWriteTimeLow),
-          VolumeSerialNumber(VolumeSerialNumber), FileSizeHigh(FileSizeHigh),
-          FileSizeLow(FileSizeLow), FileIndexHigh(FileIndexHigh),
-          FileIndexLow(FileIndexLow), Type(Type), Perms(perms_not_known) {}
+      : LastAccessedTimeHigh(0), LastAccessedTimeLow(0),
+        LastWriteTimeHigh(LastWriteTimeHigh),
   #endif
 
   // getters
   file_type type() const { return Type; }
   perms permissions() const { return Perms; }
+  TimeValue getLastAccessedTime() const;
   TimeValue getLastModificationTime() const;
   UniqueID getUniqueID() const;
 
   #if defined(LLVM_ON_UNIX)
   uint32_t getUser() const { return fs_st_uid; }
   uint32_t getGroup() const { return fs_st_gid; }
   uint64_t getSize() const { return fs_st_size; }
   #elif defined (LLVM_ON_WIN32)

lib/Support/Unix/Path.inc

#elif defined(HAVE_DLFCN_H)
   if (realpath(DLInfo.dli_fname, link_path))
     return link_path;
 #else
 #error GetMainExecutable is not implemented on this host yet.
 #endif
   return "";
 }
 
+TimeValue file_status::getLastAccessedTime() const {
+  TimeValue Ret;
+  Ret.fromEpochTime(fs_st_atime);
+  return Ret;
+}
+
 TimeValue file_status::getLastModificationTime() const {
   TimeValue Ret;
   Ret.fromEpochTime(fs_st_mtime);
   return Ret;
 }
 
 UniqueID file_status::getUniqueID() const {
   return UniqueID(fs_st_dev, fs_st_ino);
else if (S_ISCHR(Status.st_mode))
     Type = file_type::character_file;
   else if (S_ISFIFO(Status.st_mode))
     Type = file_type::fifo_file;
   else if (S_ISSOCK(Status.st_mode))
     Type = file_type::socket_file;
 
   perms Perms = static_cast<perms>(Status.st_mode);
   Result =
-      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
-                  Status.st_uid, Status.st_gid, Status.st_size);
+      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_atime,
+                  Status.st_mtime, Status.st_uid, Status.st_gid,
+                  Status.st_size);
 
   return std::error_code();
 }
 
 std::error_code status(const Twine &Path, file_status &Result) {
   SmallString<128> PathStorage;
   StringRef P = Path.toNullTerminatedStringRef(PathStorage);
 

lib/Support/Windows/Path.inc

UniqueID file_status::getUniqueID() const {
   // 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::getLastAccessedTime() const {
+  ULARGE_INTEGER UI;
+  UI.LowPart = LastAccessedTimeLow;
+  UI.HighPart = LastAccessedTimeHigh;
+
+  TimeValue Ret;
+  Ret.fromWin32Time(UI.QuadPart);
+  return Ret;
+}
+
 TimeValue file_status::getLastModificationTime() const {
   ULARGE_INTEGER UI;
   UI.LowPart = LastWriteTimeLow;
   UI.HighPart = LastWriteTimeHigh;
 
   TimeValue Ret;
   Ret.fromWin32Time(UI.QuadPart);
   return Ret;

 
 bool can_execute(const Twine &Path) {
   return !access(Path, AccessMode::Execute) ||
          !access(Path + ".exe", AccessMode::Execute);
 }
 
 bool equivalent(file_status A, file_status B) {
   assert(status_known(A) && status_known(B));
-  return A.FileIndexHigh      == B.FileIndexHigh &&
-         A.FileIndexLow       == B.FileIndexLow &&
-         A.FileSizeHigh       == B.FileSizeHigh &&
-         A.FileSizeLow        == B.FileSizeLow &&
-         A.LastWriteTimeHigh  == B.LastWriteTimeHigh &&
-         A.LastWriteTimeLow   == B.LastWriteTimeLow &&
-         A.VolumeSerialNumber == B.VolumeSerialNumber;
+  return A.FileIndexHigh         == B.FileIndexHigh &&
+         A.FileIndexLow          == B.FileIndexLow &&
+         A.FileSizeHigh          == B.FileSizeHigh &&
+         A.FileSizeLow           == B.FileSizeLow &&
+         A.LastAccessedTimeHigh  == B.LastAccessedTimeHigh &&
+         A.LastAccessedTimeLow   == B.LastAccessedTimeLow &&
+         A.LastWriteTimeHigh     == B.LastWriteTimeHigh &&
+         A.LastWriteTimeLow      == B.LastWriteTimeLow &&
+         A.VolumeSerialNumber    == B.VolumeSerialNumber;
 }
 
 std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   file_status fsA, fsB;
   if (std::error_code ec = status(A, fsA))
     return ec;
   if (std::error_code ec = status(B, fsB))
     return ec;
static std::error_code getStatus(HANDLE FileHandle, file_status &Result) {
   if (!::GetFileInformationByHandle(FileHandle, &Info))
     goto handle_status_error;
 
   {
     file_type Type = (Info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
                          ? file_type::directory_file
                          : file_type::regular_file;
     Result =
-        file_status(Type, Info.ftLastWriteTime.dwHighDateTime,
+        file_status(Type, Info.lpLastAccessTime.dwHighDateTime,
+                    Info.lpLastAccessTime.dwLowDateTime,
+                    Info.ftLastWriteTime.dwHighDateTime,
                     Info.ftLastWriteTime.dwLowDateTime,
                     Info.dwVolumeSerialNumber, Info.nFileSizeHigh,
                     Info.nFileSizeLow, Info.nFileIndexHigh, Info.nFileIndexLow);
     return std::error_code();
   }
 
 handle_status_error:
   DWORD LastError = ::GetLastError();