Add a version of sys::fs::status that uses fstat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186378 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 71 insertions, 40 deletions

diff --git a/include/llvm/Support/FileSystem.h b/include/llvm/Support/FileSystem.h
index 8b63015..5ed151d 100644
--- a/include/llvm/Support/FileSystem.h
+++ b/include/llvm/Support/FileSystem.h
@@ -529,6 +529,9 @@ error_code is_symlink(const Twine &path, bool &result);
 ///          platform specific error_code.
 error_code status(const Twine &path, file_status &result);
 
+/// @brief A version for when a file descriptor is already available.
+error_code status(int FD, file_status &Result);
+
 /// @brief Get file size.
 ///
 /// @param Path Input path.
diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index 484296c..9795b6e 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -541,43 +541,55 @@ error_code getUniqueID(const Twine Path, uint64_t &Result) {
   return error_code::success();
 }
 
-error_code status(const Twine &path, file_status &result) {
-  SmallString<128> path_storage;
-  StringRef p = path.toNullTerminatedStringRef(path_storage);
-
-  struct stat status;
-  if (::stat(p.begin(), &status) != 0) {
+static error_code fillStatus(int StatRet, const struct stat &Status,
+                             file_status &Result) {
+  if (StatRet != 0) {
     error_code ec(errno, system_category());
     if (ec == errc::no_such_file_or_directory)
-      result = file_status(file_type::file_not_found);
+      Result = file_status(file_type::file_not_found);
     else
-      result = file_status(file_type::status_error);
+      Result = file_status(file_type::status_error);
     return ec;
   }
 
-  perms prms = static_cast<perms>(status.st_mode);
   file_type Type = file_type::type_unknown;
 
-  if (S_ISDIR(status.st_mode))
+  if (S_ISDIR(Status.st_mode))
     Type = file_type::directory_file;
-  else if (S_ISREG(status.st_mode))
+  else if (S_ISREG(Status.st_mode))
     Type = file_type::regular_file;
-  else if (S_ISBLK(status.st_mode))
+  else if (S_ISBLK(Status.st_mode))
     Type = file_type::block_file;
-  else if (S_ISCHR(status.st_mode))
+  else if (S_ISCHR(Status.st_mode))
     Type = file_type::character_file;
-  else if (S_ISFIFO(status.st_mode))
+  else if (S_ISFIFO(Status.st_mode))
     Type = file_type::fifo_file;
-  else if (S_ISSOCK(status.st_mode))
+  else if (S_ISSOCK(Status.st_mode))
     Type = file_type::socket_file;
 
-  result =
-      file_status(Type, prms, status.st_dev, status.st_ino, status.st_mtime,
-                  status.st_uid, status.st_gid, status.st_size);
+  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);
 
   return error_code::success();
 }
 
+error_code status(const Twine &Path, file_status &Result) {
+  SmallString<128> PathStorage;
+  StringRef P = Path.toNullTerminatedStringRef(PathStorage);
+
+  struct stat Status;
+  int StatRet = ::stat(P.begin(), &Status);
+  return fillStatus(StatRet, Status, Result);
+}
+
+error_code status(int FD, file_status &Result) {
+  struct stat Status;
+  int StatRet = ::fstat(FD, &Status);
+  return fillStatus(StatRet, Status, Result);
+}
+
 error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
 #if defined(HAVE_FUTIMENS)
   timespec Times[2];
diff --git a/lib/Support/Windows/Path.inc b/lib/Support/Windows/Path.inc
index 1ecd803..5787636 100644
--- a/lib/Support/Windows/Path.inc
+++ b/lib/Support/Windows/Path.inc
@@ -598,6 +598,35 @@ static bool isReservedName(StringRef path) {
   return false;
 }
 
+static error_code getStatus(HANDLE FileHandle, file_status &Result) {
+  if (FileHandle == INVALID_HANDLE_VALUE)
+    goto handle_status_error;
+
+  BY_HANDLE_FILE_INFORMATION Info;
+  if (!::GetFileInformationByHandle(FileHandle, &Info))
+    goto handle_status_error;
+
+  Result = file_status(
+        file_type::regular_file, Info.ftLastWriteTime.dwHighDateTime,
+        Info.ftLastWriteTime.dwLowDateTime, Info.dwVolumeSerialNumber,
+        Info.nFileSizeHigh, Info.nFileSizeLow, Info.nFileIndexHigh,
+        Info.nFileIndexLow);
+  return error_code::success();
+
+handle_status_error:
+  error_code EC = windows_error(::GetLastError());
+  if (EC == windows_error::file_not_found ||
+      EC == windows_error::path_not_found)
+    Result = file_status(file_type::file_not_found);
+  else if (EC == windows_error::sharing_violation)
+    Result = file_status(file_type::type_unknown);
+  else {
+    Result = file_status(file_type::status_error);
+    return EC;
+  }
+  return error_code::success();
+}
+
 error_code status(const Twine &path, file_status &result) {
   SmallString<128> path_storage;
   SmallVector<wchar_t, 128> path_utf16;
@@ -613,7 +642,7 @@ error_code status(const Twine &path, file_status &result) {
 
   DWORD attr = ::GetFileAttributesW(path_utf16.begin());
   if (attr == INVALID_FILE_ATTRIBUTES)
-    goto handle_status_error;
+    return getStatus(INVALID_HANDLE_VALUE, result);
 
   // Handle reparse points.
   if (attr & FILE_ATTRIBUTE_REPARSE_POINT) {
@@ -626,7 +655,7 @@ error_code status(const Twine &path, file_status &result) {
                     FILE_FLAG_BACKUP_SEMANTICS,
                     0));
     if (!h)
-      goto handle_status_error;
+      return getStatus(INVALID_HANDLE_VALUE, result);
   }
 
   if (attr & FILE_ATTRIBUTE_DIRECTORY)
@@ -641,32 +670,19 @@ error_code status(const Twine &path, file_status &result) {
                     FILE_FLAG_BACKUP_SEMANTICS,
                     0));
     if (!h)
-      goto handle_status_error;
+      return getStatus(INVALID_HANDLE_VALUE, result);
     BY_HANDLE_FILE_INFORMATION Info;
     if (!::GetFileInformationByHandle(h, &Info))
-      goto handle_status_error;
+      return getStatus(INVALID_HANDLE_VALUE, result);
 
-    result = file_status(
-        file_type::regular_file, Info.ftLastWriteTime.dwHighDateTime,
-        Info.ftLastWriteTime.dwLowDateTime, Info.dwVolumeSerialNumber,
-        Info.nFileSizeHigh, Info.nFileSizeLow, Info.nFileIndexHigh,
-        Info.nFileIndexLow);
+    return getStatus(h, result);
   }
   return error_code::success();
+}
 
-handle_status_error:
-  error_code ec = windows_error(::GetLastError());
-  if (ec == windows_error::file_not_found ||
-      ec == windows_error::path_not_found)
-    result = file_status(file_type::file_not_found);
-  else if (ec == windows_error::sharing_violation)
-    result = file_status(file_type::type_unknown);
-  else {
-    result = file_status(file_type::status_error);
-    return ec;
-  }
-
-  return error_code::success();
+error_code status(int FD, file_status &Result) {
+  HANDLE FileHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
+  return getStatus(FileHandle, Result);
 }
 
 error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {