[Support] NFC: Allow modifying access/modification times independently in sys::fs::setLastModificationAndAccessTime.

Summary:
Add an overload to sys::fs::setLastModificationAndAccessTime that allows setting last access and modification times separately. This will allow tools to use this API when they want to preserve both the access and modification times from an input file, which may be different.

Also note that both the POSIX (futimens/futimes) and Windows (SetFileTime) APIs take the two timestamps in the order of (1) access (2) modification time, so this renames the method to "setLastAccessAndModificationTime" to make it clear which timestamp is which.

For existing callers, the 1-arg overload just sets both timestamps to the same thing.

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50521

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339628 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/FileSystem.h

@@ -666,7 +666,15 @@ inline std::error_code file_size(const Twine &Path, uint64_t &Result) {
 /// @returns errc::success if the file times were successfully set, otherwise a
 ///          platform-specific error_code or errc::function_not_supported on
 ///          platforms where the functionality isn't available.
-std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time);
+std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
+                                                 TimePoint<> ModificationTime);
+
+/// Simpler version that sets both file modification and access time to the same
+/// time.
+inline std::error_code setLastAccessAndModificationTime(int FD,
+                                                        TimePoint<> Time) {
+  return setLastAccessAndModificationTime(FD, Time, Time);
+}
 
 /// Is status available?
 ///

lib/Support/Unix/Path.inc

@@ -583,17 +583,22 @@ std::error_code setPermissions(const Twine &Path, perms Permissions) {
   return std::error_code();
 }
 
-std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) {
+std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
+                                                 TimePoint<> ModificationTime) {
 #if defined(HAVE_FUTIMENS)
   timespec Times[2];
-  Times[0] = Times[1] = sys::toTimeSpec(Time);
+  Times[0] = sys::toTimeSpec(AccessTime);
+  Times[1] = sys::toTimeSpec(ModificationTime);
   if (::futimens(FD, Times))
     return std::error_code(errno, std::generic_category());
   return std::error_code();
 #elif defined(HAVE_FUTIMES)
   timeval Times[2];
-  Times[0] = Times[1] = sys::toTimeVal(
-      std::chrono::time_point_cast<std::chrono::microseconds>(Time));
+  Times[0] = sys::toTimeVal(
+      std::chrono::time_point_cast<std::chrono::microseconds>(AccessTime));
+  Times[1] =
+      sys::toTimeVal(std::chrono::time_point_cast<std::chrono::microseconds>(
+          ModificationTime));
   if (::futimes(FD, Times))
     return std::error_code(errno, std::generic_category());
   return std::error_code();

lib/Support/Windows/Path.inc

@@ -766,10 +766,12 @@ std::error_code setPermissions(const Twine &Path, perms Permissions) {
   return std::error_code();
 }
 
-std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) {
-  FILETIME FT = toFILETIME(Time);
+std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
+                                                 TimePoint<> ModificationTime) {
+  FILETIME AccessFT = toFILETIME(AccessTime);
+  FILETIME ModifyFT = toFILETIME(ModificationTime);
   HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
-  if (!SetFileTime(FileHandle, NULL, &FT, &FT))
+  if (!SetFileTime(FileHandle, NULL, &AccessFT, &ModifyFT))
     return mapWindowsError(::GetLastError());
   return std::error_code();
 }

tools/llvm-ar/llvm-ar.cpp

@@ -410,7 +410,7 @@ static void doExtract(StringRef Name, const object::Archive::Child &C) {
     auto ModTimeOrErr = C.getLastModified();
     failIfError(ModTimeOrErr.takeError());
     failIfError(
-        sys::fs::setLastModificationAndAccessTime(FD, ModTimeOrErr.get()));
+        sys::fs::setLastAccessAndModificationTime(FD, ModTimeOrErr.get()));
   }
 
   if (close(FD))

unittests/Support/Path.cpp

@@ -1297,7 +1297,7 @@ TEST_F(FileSystemTest, OpenFileForRead) {
   ASSERT_NO_ERROR(sys::fs::openFileForWrite(Twine(TempPath), FileDescriptor,
                                             fs::CD_OpenExisting));
   TimePoint<> Epoch(std::chrono::milliseconds(0));
-  ASSERT_NO_ERROR(fs::setLastModificationAndAccessTime(FileDescriptor, Epoch));
+  ASSERT_NO_ERROR(fs::setLastAccessAndModificationTime(FileDescriptor, Epoch));
   ::close(FileDescriptor);
 
   // Open the file and ensure access time is updated, when forced.