From 5908affee9a96df72480d7cb963d6412a91556a2 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Tue, 21 Nov 2017 01:52:44 +0000
Subject: [PATCH] Split a rename_handle out of rename on windows.

llvm-svn: 318725
---
 llvm/lib/Support/Windows/Path.inc | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index df39ac7..1830625 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -418,14 +418,13 @@ static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
   return std::error_code();
 }
 
+static std::error_code rename_handle(HANDLE Handle, const Twine &To);
+
 std::error_code rename(const Twine &From, const Twine &To) {
   // Convert to utf-16.
   SmallVector<wchar_t, 128> WideFrom;
-  SmallVector<wchar_t, 128> WideTo;
   if (std::error_code EC = widenPath(From, WideFrom))
     return EC;
-  if (std::error_code EC = widenPath(To, WideTo))
-    return EC;
 
   ScopedFileHandle FromHandle;
   // Retry this a few times to defeat badly behaved file system scanners.
@@ -442,6 +441,14 @@ std::error_code rename(const Twine &From, const Twine &To) {
   if (!FromHandle)
     return mapWindowsError(GetLastError());
 
+  return rename_handle(FromHandle, To);
+}
+
+static std::error_code rename_handle(HANDLE FromHandle, const Twine &To) {
+  SmallVector<wchar_t, 128> WideTo;
+  if (std::error_code EC = widenPath(To, WideTo))
+    return EC;
+
   // We normally expect this loop to succeed after a few iterations. If it
   // requires more than 200 tries, it's more likely that the failures are due to
   // a true error, so stop trying.
@@ -452,6 +459,9 @@ std::error_code rename(const Twine &From, const Twine &To) {
         std::error_code(ERROR_CALL_NOT_IMPLEMENTED, std::system_category())) {
       // Wine doesn't support SetFileInformationByHandle in rename_internal.
       // Fall back to MoveFileEx.
+      SmallVector<wchar_t, MAX_PATH> WideFrom;
+      if (std::error_code EC2 = realPathFromHandle(FromHandle, WideFrom))
+        return EC2;
       if (::MoveFileExW(WideFrom.begin(), WideTo.begin(),
                         MOVEFILE_REPLACE_EXISTING))
         return std::error_code();
-- 
2.7.4