Use status to implement file_size.

The status function is already using a syscall that returns the file size.
Remember it and implement file_size as a simple wrapper.

No functionally change, but clients that already use status now can avoid
calling file_size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186016 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/FileSystem.h

@@ -153,6 +153,7 @@ class file_status
   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 LastWriteTimeHigh;
   uint32_t LastWriteTimeLow;
@@ -180,6 +181,7 @@ public:
   #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)
   uint32_t getUser() const {
     return 9999; // Not applicable to Windows, so...
@@ -187,6 +189,9 @@ public:
   uint32_t getGroup() const {
     return 9999; // Not applicable to Windows, so...
   }
+  uint64_t getSize() const {
+    return (uint64_t(FileSizeHigh) << 32) + FileSizeLow;
+  }
   #endif
 
   // setters
@@ -435,7 +440,14 @@ inline bool equivalent(const Twine &A, const Twine &B) {
 /// @param result Set to the size of the file in \a path.
 /// @returns errc::success if result has been successfully set, otherwise a
 ///          platform specific error_code.
-error_code file_size(const Twine &path, uint64_t &result);
+inline error_code file_size(const Twine &Path, uint64_t &Result) {
+  file_status Status;
+  error_code EC = status(Path, Status);
+  if (EC)
+    return EC;
+  Result = Status.getSize();
+  return error_code::success();
+}
 
 /// @brief Does status represent a directory?
 ///

lib/Support/Unix/Path.inc

@@ -529,20 +529,6 @@ error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   return error_code::success();
 }
 
-error_code file_size(const Twine &path, uint64_t &result) {
-  SmallString<128> path_storage;
-  StringRef p = path.toNullTerminatedStringRef(path_storage);
-
-  struct stat status;
-  if (::stat(p.begin(), &status) == -1)
-    return error_code(errno, system_category());
-  if (!S_ISREG(status.st_mode))
-    return make_error_code(errc::operation_not_permitted);
-
-  result = status.st_size;
-  return error_code::success();
-}
-
 error_code getUniqueID(const Twine Path, uint64_t &Result) {
   SmallString<128> Storage;
   StringRef P = Path.toNullTerminatedStringRef(Storage);
@@ -591,6 +577,7 @@ error_code status(const Twine &path, file_status &result) {
   result.fs_st_mtime = status.st_mtime;
   result.fs_st_uid = status.st_uid;
   result.fs_st_gid = status.st_gid;
+  result.fs_st_size = status.st_size;
 
   return error_code::success();
 }

lib/Support/Windows/Path.inc

@@ -555,27 +555,6 @@ error_code equivalent(const Twine &A, const Twine &B, bool &result) {
   return error_code::success();
 }
 
-error_code file_size(const Twine &path, uint64_t &result) {
-  SmallString<128> path_storage;
-  SmallVector<wchar_t, 128> path_utf16;
-
-  if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
-                                  path_utf16))
-    return ec;
-
-  WIN32_FILE_ATTRIBUTE_DATA FileData;
-  if (!::GetFileAttributesExW(path_utf16.begin(),
-                              ::GetFileExInfoStandard,
-                              &FileData))
-    return windows_error(::GetLastError());
-
-  result =
-    (uint64_t(FileData.nFileSizeHigh) << (sizeof(FileData.nFileSizeLow) * 8))
-    + FileData.nFileSizeLow;
-
-  return error_code::success();
-}
-
 error_code getUniqueID(const Twine Path, uint64_t &Result) {
   file_status Status;
   if (error_code E = status(Path, Status))