[dsymutil] Simplify temporary file handling.

Dsymutil's update functionality was broken on Windows because we tried
to rename a file while we're holding open handles to that file. TempFile
provides a solution for this through its keep(Twine) method. This patch
changes dsymutil to make use of that functionality.

Differential revision: https://reviews.llvm.org/D49860

llvm-svn: 338216

2 files changed, 8 insertions, 4 deletions

diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index a806da23ec5..098230290ed 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -1157,9 +1157,13 @@ Error TempFile::keep(const Twine &Name) {
     setDeleteDisposition(H, true);
 #else
   std::error_code RenameEC = fs::rename(TmpName, Name);
-  // If we can't rename, discard the temporary file.
-  if (RenameEC)
-    remove(TmpName);
+  if (RenameEC) {
+    // If we can't rename, try to copy to work around cross-device link issues.
+    RenameEC = sys::fs::copy_file(TmpName, Name);
+    // If we can't rename or copy, discard the temporary file.
+    if (RenameEC)
+      remove(TmpName);
+  }
   sys::DontRemoveFileOnSignal(TmpName);
 #endif
 
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index f425d607af4..b64b013d740 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -450,7 +450,7 @@ static std::error_code rename_handle(HANDLE FromHandle, const Twine &To) {
       if (std::error_code EC2 = realPathFromHandle(FromHandle, WideFrom))
         return EC2;
       if (::MoveFileExW(WideFrom.begin(), WideTo.begin(),
-                        MOVEFILE_REPLACE_EXISTING))
+                        MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED))
         return std::error_code();
       return mapWindowsError(GetLastError());
     }