[Support] Fix FileNameLength passed to SetFileInformationByHandle

The rename_internal function used for Windows has a minor bug where the
filename length is passed as a character count instead of a byte count.
Windows internally ignores this field, but other tools that hook NT
api's may use the documented behavior:

MSDN documentation specifying the size should be in bytes:
https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_rename_info

Patch by Ben Hillis.

Differential Revision: https://reviews.llvm.org/D55624

llvm-svn: 348995

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index 678c9a819d8..d34aa763124 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -416,7 +416,7 @@ static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
       *reinterpret_cast<FILE_RENAME_INFO *>(RenameInfoBuf.data());
   RenameInfo.ReplaceIfExists = ReplaceIfExists;
   RenameInfo.RootDirectory = 0;
-  RenameInfo.FileNameLength = ToWide.size();
+  RenameInfo.FileNameLength = ToWide.size() * sizeof(wchar_t);
   std::copy(ToWide.begin(), ToWide.end(), &RenameInfo.FileName[0]);
 
   SetLastError(ERROR_SUCCESS);